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Biochemistry
FA complete review part 1
| Question | Answer |
|---|---|
| What is the condensed form of DNA called? | Chromatin |
| Which histone is termed the "linker"? | H1 |
| What gives DNA its negative charge? | Phosphate groups |
| What amino acids give histones its positive charge? | Lysine and arginine |
| What is the overall charge of DNA? | Negative |
| What is the charge of histones? | Positive |
| Which histone is not part of the nucleosome? | H1 |
| What are the histones that form the Nucleosome? | H2A, H2B, H3, and H4 (x2) |
| What is an Nucleosome? | Histone octamer surrounded by DNA |
| What is the relation between DNA and a Nucleosome? | DNA loops twice around a histone octamer to form an nucleosome. |
| In which phase is DNA and histone synthesized? | S-phase |
| What happens to DNA during mitosis? | DNA condenses to form chromosomes |
| What is unique about mitochondria in respect to DNA content? | It has its own DNA, which is circular and does not utilize histones |
| Which is the form of condensed chromatin? | Heterochromatin |
| What form of chromatin is transcriptionally inactive and sterically inaccessible? | Heterochromatin |
| Which form of chromatin features an increase in methylation and decrease in acetylation? | Heterochromatin |
| Highly condensed chromatin | Heterochromatin |
| What are Barr bodies? | Inactive X chromosomes |
| Where are Barr bodies usually found? | Periphery of nucleus |
| Which form chromatin appears lighter on EM? | Euchromatin |
| Euchromatin is: | Transcriptionally active and sterically accessible |
| What is does DNA methylation accomplishes? | Changes the expression of DNA segment without changing the sequence |
| What are some situations in which there is DNA methylation involvement? | -Genomic imprinting, X-chromosome inactivation, repression of transposable elements, aging, and carcinogenesis |
| The process of aging is associated with DNA ___________. | Methylation |
| What happens in case of methylation within gene promoter? | Represses gene transcription |
| What are CpG sites? | Regions of DNA where cytosine nucleotide is followed by guanine nucleotide along the linear sequence of bases in the 5'--> 3' direction |
| What happens in Histone methylation? | Reversible transcriptional suppression, but can also cause activation depending on location of methyl groups |
| Mute DNA is produced by which process? | Histone methylation |
| What process causes the relaxation of DNA coiling, allowing for transcription? | Histone acetylation |
| What process makes DNA active? | Histone acetylation |
| What is the compositional difference between a nucleoside and a Nucleotide? | Nucleoside has an added Sugar, while a nucleotide has an added phosphate |
| Base + (deoxy)ribose + phosphate = | Nucleotide |
| What links together the phosphate in a nucleotide? | 3'-5' phosphodiester bond |
| How many rings are in the Purine structure? | 2 |
| A nucleotide with one ring only is a _____________________. | Pyrimidine |
| Which are the two Purines? | Guanine and Adenine |
| Which are the 3 Pyrimidines? | Cytosine, Uracil, and Thiamine |
| Uracil is found in __________. | RNA |
| Thymine is found in ________________. | DNA |
| The methylation of uracil makes ____________. | Thymine |
| What is the added group to thymine, that differs it form Uracil? | Methyl group |
| Which nucleotides for a 3 H bond? | G === C |
| A--T bond has _____ H bonds. | 2 |
| What type of bonds are responsible for increasing the melting point of DNA? | G === C |
| What amino acids are necessary to create Purines? | Glycine, Aspartate, and Glutamine |
| List of drugs that interfere or prevent Pyrimidine synthesis? | -Leflunomide -Methotrexate (MTX), trimethoprim (TMP), and Pyrimethamine - 5- fluorouracil (5-FU) |
| Leflunomide inhibits which enzyme? | dihydroorotate dehydrogenase |
| What components are needed the de novo purine salvage pathway? | Aspartate, glycine, glutamine, and THF |
| What enzyme is inhibited by MTX? | Dihydrofolate reductase |
| A decrease of dTMP in humans is commonly due to use of: | MTX and/or 5-FU |
| What drug is used to inhibit dihydrofolate reductase in bacteria? | TMP |
| What type of dihydrofolate reductase inhibitor is used in Protozoan infections? | Pyrimethamine |
| Which enzyme is inhibited by 5-FU? | Thymidylate synthase |
| What is a common Thymidylate synthase inhibitor? | 5-FU |
| What are 3 common drugs that inhibit Purine synthesis? | - 6-mercaptopurine (6-MP), - Mycophenolate and Ribavirin |
| What is the prodrug of 6-MP? | Azathioprine |
| Azathioprine inhibits the ___________. | de novo purine synthesis |
| What enzyme is inhibited by Mycophenolate and by Ribavirin? | Inosine monophosphate dehydrogenase |
| Enzyme inhibited by Hydroxyurea? | Ribonucleotide reductase |
| Drug that inhibits both, Purine and Pyrimidine, synthesis? | Hydroxyurea |
| CPS2 is used in the ____. | Cytosol |
| What are characteristics shared by Eukaryotic and Prokaryotic DNA replication? | - Semiconservative (involves both continuous and discontinuous synthesis) - Occurs in the 5' ---> 3' direction |
| What is the direction of DNA replication? | 5' -----> 3' |
| What are the name of the discontinuous fragments of DNA replication? | Okazaki fragments |
| What is the Origin of Replication? | Particular consensus sequence of base pairs in genome where DNA replication begins |
| Which type of DNA replication depicts multiple origins of replication? | Eukaryote |
| How many origins of replication are seen in Prokaryotic DNA replication? | Single (one) |
| What would a AT-rich sequence in DNA indicate? | Areas of promoters and origins of replication |
| What is an example of a popular AT-rice sequence area? | TATA box regions |
| What is the Replication fork? | Y-shaped region along DNA template where leading and lagging strands are synthesized |
| What is the role of Helicase? | Unwinds DNA template at replication fork |
| Where does the Helicase work? | Replication Fork |
| What is the role of Single-stranded binding proteins? | Prevent strands from reannealing |
| What prevents DNA strands (leading and lagging) in DNA replication form annealing before time? | Single-stranded binding proteins |
| What is the function of DNA topoisomerases? | Create a single or double-stranded break in the helix to add or remove supercoils |
| What proteins are used to add or remove supercoils in DNA helix at moment of DNA replication? | DNA Topoisomerases |
| In Eukaryotes, TOP I is inhibited by which drugs? | Irinotecan/Topotecan |
| TOP II in eukaryotes is inhibited by: | Etoposide/Teniposide |
| Etoposide inhibits: | Topoisomerase II (TOP II) in eukaryotes cells. |
| Which type of cells do fluoroquinolones work? | Prokaryotes |
| Which TOPs are inhibited by fluoroquinolones? | II and IV |
| What is a common name for Prokaryotic TOP II? | DNA gyrase |
| What is the function of Primase? | Makes an RNA primer on which DNA polymerase III can initiate replication |
| Which DNA pol work on RNA primer to start replication? | III |
| DNA Pol III is found in ____________________ only. | Prokaryotic |
| Which DNA polymerases are only found in Prokaryotic organisms? | I and III |
| What is the role of DNA pol III in the prokaryotic leading strand? | Elongation by adding deoxynucleotides to the 3' end |
| The elongation of the lagging strand by DNA pol III is stopt as it reaches the _____________. | Primer |
| What is a key characteristic of DNA pol III? | 3' ---> 5' exonuclease activity "proofreads" each added nucleotide |
| What is the direction of DNA pol III synthesis? | 5' --> 3' |
| What is the direction of DNA Pol III proofreading activity? | 3' ---> 5' |
| What is the purpose of drugs having a modified 3' OH? | Prevent the addition of the next nucleotide by DNA pol III |
| What is the function of DNA pol I? | Degrades RNA primer; replaces it with DNA |
| How is the RNA primer excised? | By DNA pol I with 5' --> 3" exonuclease activity |
| What is the function of DNA ligase? | Catalyzes the formation of phosphodiester bond within a strand of dsDNA |
| What protein is in charge of joining Okazaki fragments? | DNA ligase |
| Telomerase is found in ___________ only. | Eukaryotes |
| What is and the function of Telomerase? | Reverse transcriptase that adds DNA to 3' ends of chromosomes to avoid genetic material with every duplication |
| What compound prevents the loss of genetic material everytime a duplication occurs? | Telomerase |
| Which enzyme is often dysregulated and allows cancer cells to have unregulated replication? | Telomerase |
| How is the reverse transcriptase of Telomerase? | RNA-dependent DNA polymerase |
| What is the added DNA by Telomerase reverse transcriptase? | TTAGGG |
| To which end of DNA do Telomerase add the new DNA ? | 3' end |
| What type of mutation of DNA is the most severe? | Frameshift |
| What is more severe, a missense or an nonse mutation of DNA? | Nonsense |
| What kind of DNA mutation is the least severe? | Silent |
| What is a Transition DNA mutation? | Change from a Purine to a purine (or Pyrimidine to Pyrimidine) |
| A DNA mutation the converts a Purine into a Pyrimidine (or vice versa) is known as: | Transversion |
| Nucleotide substitution but codes for the same amino acid. | Silent mutation |
| What is the base change MC seen in a silent mutation? | 3rd base |
| What is tRNA wobble? | Base change in 3rd position of codon |
| Very common disease due to a Missense mutation? | Sickle cell disease |
| What is the mutation seen in Sickle cell disease? | Missense |
| Substitution of Glutamic acid with valine. Dx? | Sickle cell disease |
| Missense mutation definition? | Nucleotide substitution resulting in changed amino acid |
| When is a missense mutation referred as conservative? | If new amino acid is similar in chemical structure |
| What amino acid replaces glutamic acid in Sickle cell disease? | Valine |
| What kind of mutation results in the premature appearance of a Stop codon? | Nonsense |
| What are the Stop Codons? | UAG, UAA, and UGA |
| What is the most common result of a nonsense DNA mutation? | Non-functional proteins |
| Two common condition due to a Frameshift mutation? | 1. Duchenne muscular dystrophy 2. Tay-Sachs disease |
| What is a Frameshift mutation? | Deletion or insertion of a number of nucleotides not divisible by 3, resulting in misreading all nucleotides downstream |
| A mutation at splice site causes: | 1. Retained intron in the mRNA ---> protein with impaired or altered function |
| What is often the cause of a retained intron in mRNA? | Mutation at the splice site |
| What form of Thalassemia is seen with a Splice site mutation? | B-thalassemia |
| B-thalassemia is commonly due to a _____________________ mutation. | Splice site |
| What is the lac operon? | Operon required for the transport and metabolism of lactose in E. coli and many other organisms |
| What the main microbial organism required of the lac operon? | E. coli |
| What is a classic example of response to an environmental change? | The use of lac operon in E. coli in the absence of glucose in the environment |
| What is activated in the metabolism of Lactose by E. coli? | Lac operon |
| What is the relation between lac operon, CAP and glucose level? | Low glucose induces the activation of CAP leading to increase transcription by lac operon in E. coli. |
| Which state creates a strong expression of lac genes? | Low glucose and lactose available |
| No glucose and no lactose available means ? | No lac genes expressed |
| Which level of glucose, low or high, induces or promotes lac gene expression? | Low glucose levels |
| What are the three types of Single strand DNA repairs? | 1. Nucleotide excision repair 2. Base excision repair 3. Mismatch repair |
| What is nucleotide excision repair? | Specific endonucleases release the oligonucleotides containing damaged bases; DNA polymerase and ligase fill and reseal the gap, respectively. |
| Nucleotide excision repair occurs in what phase to the cell cycle? | Phase 1 |
| What is a common condition due to a defective Nucleotide excision repair? | Xeroderma pigmentosum |
| What is defective in Xeroderma pigmentosum? | The nucleotide excision repair is unable to repair DNA pyrimidine dimers caused by UV exposure. |
| What are some important findings of Xeroderma pigmentosum? | Dry skin, extreme light sensitivity, skin cancer |
| What is base excision repair? | Base-specific Glycosylase removes altered base and creates AP site |
| In which end of nucleotide does the AP-endonuclease work? | 5' endo |
| Unlike Nucleotide excision repair, the base excision repair occurs ___________________ of the cell cycle. | Throughout the entire |
| What DNA repair mechanism is especially important in spontaneous/toxic deamination? | Base excision repair |
| What is Mismatch repair? | Newly synthesized strand is recognized, mismatched nucleotides are removed, and the gap is filled an resealed. |
| What condition is due to a defective mismatch repair? | Lynch syndrome ( hereditary nonpolyposis colorectal cancer [NNPCC]) |
| Mismatch repair mainly occurs during which phase of the cell cycle? | S-phase |
| WHat are the two kinds of double strand DNA repair? | 1. Non-homologous end joining 2. Homologous recombination |
| What condition is seen with defective Non-homologous end joining? | Ataxia telangiectasia and Fanconi anemia |
| Defective Homologous recombination gives rise to: | Breast/Ovarian cancer with BRCA1 mutation |
| What is Nonhomologous end joining DNA repair? | The bringing together of 2 ends of DNA fragments to repair double-stranded breaks |
| Which kind of double stranded DNA repair does not require DNA homology? | Nonhomologous end joining |
| Requireds two homologous DNA duplexes | Homologous recombination |
| What describes homologous recombination? | A strand fro the damaged dsDNA is repaired using a complementary strand from the intact homologous dsDNA as a template |
| Which type of double stranded DNA repair does not loss any genetic material? | Homologous recombination |
| What is the mRNA start codon? | AUG |
| AUG is: | mRNA start codon |
| Describe the start codon (AUG) in eukaryotes. | Codes for methionine, which may be removed before translation is completed |
| AUG in eukaryotic cells code for? | Methionine |
| What does AUG codes in prokaryotic cells? | N-formylmethionine (fMet) |
| What is "fMet"? | The coding of UAG in prokaryotes |
| What is a alternate function of fMet? | Stimulation of neutrophil chemotaxis |
| Name the 3 stop codons: | 1. UGA 2. UAA 3. UAG |
| The promoter is on the _______ end of the gene. | 5' end |
| What makes up the promoter in Eukaryotic genes? | CAAT box and TATA box |
| AATAAA is? | Polyadenylation signal |
| Which end of the gene has the polyadenylation signal? | 3' end |
| What are the main factors or proteins involved in the regulation of gene expression? | Promoters, Enhancers, and Silencers |
| What is the promoter? | Site where RNA polymerase II and multiple other transcription factors bind to DNA upstream for gene locus |
| What is a common result from a promoter mutation? | Dramatic decrease in level of gene transcription |
| Sudden, severe decrease in level of transcription, it most commonly indicate? | Promoter mutation |
| Another name for an Enhancer? | Activator |
| What is the function of Enhancers? | DNA locus where regulatory proteins bind --> increasing expression of a gene on the the same chromosome |
| Which regulator of gene expression increases the expression? | Enhancer |
| DNA locus in which regulatory proteins bind and cause the decrease of gene expression on same chromosome? | Silencer |
| In base excision repair: | Only the damaged base is removed and repair the gap. |
| How many RNA polymerases are in Prokaryotes? | One RNA polymerase makes all 3 kinds of RNA |
| Which drug works by inhibiting DNA-dependent RNA polymerase in prokaryotes? | Rifampin |
| Rifampin works on: | Prokaryotic DNA-dependent RNA polymerase |
| How many types of RNA polymerases are in Eukaryotic organism? | 3 |
| What RNA pol makes rRNA in eukaryotic cell? | RNA pol I |
| What is the most common type of RNA in eukaryotic cells? | rRNA made by RNA pol I |
| Where is rRNA only found? | Nucleolus |
| What is the largest RNA, and most massive RNA in eukaryotic cells? | mRNA |
| Which RNA pol creates mRNA? | RNA pol II |
| In what direction is mRNA read? | 5' to 3' |
| What kind of RNA pol makes 5S rRNA, tRNA? | RNA pol III |
| What is common function of RNA polymerase II? | Opens DNA at proomter site |
| What substance can inhibit RNA pol II/ | a-amanitin |
| Where is a-amanitin found? | Amanita phalloides |
| Actinomycin D MOA? | Inhibits RNA polymerase in both prokaryotes and eukaryotes |
| In RNA processing (eukaryotic) what is the initial transcript? | Heterogenous nuclear RNA (hnRNA) |
| What are 3 important processes occur in the nucleus to RNA processing? | 1. Capping of 5' end 2. Polyadenylation of 3' end 3. Splicing out of introns |
| What occurs by Capping of 5' in RNA processing? | Addition of 7-methylguanosine cap |
| Capped, tailed, and sliced transcript refers to: | mRNA |
| Where is mRNA translated? | Cytosol |
| What is in charge of mRNA quality control? | P-bodies in the cytosol |
| P-bodies contain: | Exonucleases, decapping enzymes, and microRNAs, which all serve as mRNA quality control |
| AAUAAA = | Polyadenylation signal in RNA |
| What are important protein in the first step of Splicing of pre-mRNA? | Small nuclear ribonucleoproteins (snRNPs) |
| During splicing of pre-mRNA, which are taken out, Exons or Introns? | Intron |
| Which end of mRNA suffers the first cleavage during Splicing of introns? | 5' end |
| Which, exon or intron, contains genetic information coding for protein? | Exon |
| Intervening noncoding segments of DNA | Intron |
| What is "Alternative Splicing"? | Splicing that produces a variety of protein products from a single hmRNA sequence |
| What are examples of Alternative splicing? | Tropomyosin variantes in muscle, Dopamine receptors in the brain, Transmembrane vs secreted Ig |
| What is the result of variant splicing of Introns and Exons? | Implicati in oncogenesis and many genetic disorders |
| What are some examples of genetic disoders due to defective Splicing? | B-thalassemia, Gaucher disease, Tay-Sachs disease, Marfan syndrome |
| What are microRNA? | Small, conserved, noncoding RNA molecules that post transcriptional regulate gene expression by targeting the 3' untranslated regions of specific mRNAs for degradation or translational repression |
| What is the possible result of abnormal expression of microRNA? | Certain malignancies due silencing an mRNA form a tumor suppressor gene |
| What is the abbreviation for microRNA? | miRNA |
| What molecules target 3' untranslated region of specific mRNAs? | miRNA |
| What is the structure of tRNA? | 75-90 nucleotides, secondary structure, cloverleaf form, anticodon end opposite 3' aminoacyl end |
| What is found in all, prokaryotic and eukaryotic, tRNA 3' end? | CCA |
| An amino acid is covalently bound to the ______________ of the tRNA. | 3' end |
| What mnemonic is used to remember the CCA 3' end of tRNA? | Can Carry Amino acids |
| Where would an amino acid bind in the tRNA? | CCA 3' end |
| Where in the tRNA does a ribosome binds? | T-arm |
| What is the role or purpose of D-arm in tRNA? | Contains dihydrouridine residues necessary for tRNA recognition by the correct aminoacyl-tRNA synthetase |
| What is the amino acid acceptor site of tRNA? | 5'- CCA-3' |
| What happens with a mischarged tRNA? | Reads usual codon but inserts wrong amino acid |
| What enzyme is in charge of properly charging the amino acid in the tRNA? | Aminoacyl-tRNA synthetase |
| How is the accuracy of amino acid selection properly regulated? | Aminoacyl-tRNA synthetase and boding of charged tRNA to the codon |
| What is another term for referring codon-anticodon? | Pairing |
| In tRNA translation the term charging refer to: | Aminoacylation |
| What is identified by Eukaryotic initiation factors (iEFs)? | The ' cap or an internal ribosome entry site |
| What is the composition of Eukaryotic ribosomes? | 40S + 60S = 80S |
| What is the composition of Prokaryotic ribosomes? | 30S +50S = 70S |
| What type of cells have an 80S ribosome? | Eukaryote |
| Which type of organism are found with 70S ribosomes? | Prokaryote |
| Synthesis of proteins in the ribosomes occurs form the ________ to the ____-terminus. | N- terminus -----> C - terminus |
| What causes the interaction of ATP and tRNA? | Activation (charging) |
| GPT and tRNA associated causes _____________________. | Translocation |
| What are the three steps involved in Protein synthesis? | Initiation --> Elongation --> Termination |
| What is the first step in the ELONGATION part of Protein synthesis? | Aminoacyl-tRNA binds to A site, which requires GTP. |
| What source of energy is required to accomplish the fist step of the Elongation process in protein synthesis? | GTP |
| Which is the only part which is not affected by the aminoacyl-tRNA binding to the A site? | Initiator methionine |
| The A site? | Incoming Aminoacyl-tRNA |
| The P site? | Accommodates growing peptide |
| The E site? | Holds Empty tRNA as it exists |
| What is the second step of elongation process? | rRNA catalyzes peptide bond formation, transfer growing polypeptide to amino acid in A site |
| What is the final and third step in the elongation process of Protein synthesis? | RIbosome advances 3 nucleotides toward 3' end of mRNA, moving peptidyl tRNA to P site |
| What is the termed used to describe the move of peptidyl tRNA to P site? | Translocation |
| Describe the Termination phase of Protein synthesis? | Release factor recognizes stop codon and halts translation --> completed polypeptide is released form ribosome |
| What are two important Post Translational modifications? | 1. Trimming 2. Covalent alterations |
| What is the post translational modification "Trimming"? | The removal of N- or C-terminal propeptides from zymogen to generate mature protein |
| The conversion of Trypsinogen to trypsin is an example of: | Trimming |
| What are the important Covalent alterations classified as Post Translational modifications? | Phosphorylation, glycosylation, hydroxylation, methylation, acetylation, and Ubiquitination |
| What is the main role a chaperone protein? | Facilitating and/or maintaining protein folding |
| What is the purpose of Checkpoints in the Cell cycle? | Control transitions between phases of cell cycle |
| What are the proteins involved in the regulation of the cell cycle? | Cyclins, cyclin-dependent kinases (CDKs), and tumor suppressors |
| Which is the shortest phase of the cell cycle? | M phase |
| What are the main two components or events of the M phase of the cell cycle? | Mitosis and Cytokinesis |
| What are the subdivisions that make up mitosis? | Prophase, Prometaphase, Metaphase, Anaphase, and Telophase |
| What are the cyclins? | Regulatory proteins that control cell cycle events |
| What is used to activate CDKs? | Cyclins |
| What is the role of Cyclin-CDK complexes? | Phosphorylate other proteins to coordinate cell cycle progression |
| What is the function of p53 and Rb tumor suppressors? | p53 induces p21, which inhibits CDKs --> hypophosphorylation of Rb --> inhibition of G1-S phase progression. |
| The hypophosphorylatoin of Rb means: | Activation of Rb |
| What is a common syndrome resulting from mutations in p53 tumor suppressor genes? | Li-Fraumeni syndrome |
| In the G1 to S phase transition growth factors bind to: | Tyrosine kinase receptors |
| What are some common growth factors that bind to Tyrosine kinase receptors? | Insulin, PDGF, EPO, EGF |
| What are examples of Permanent cell types? | Neurons, skeletal and cardiac muscle, RBCs |
| Remain in G 0, regenerate from stem cells | Permanent cells |
| Which are common examples of Stable cells? | Hepatocytes, lymphocytes, PCT, and Periosteal cells |
| What is another name of Stable cells? | Quiescent cells |
| Enter G1 from G0 when stimulated | Stable cells |
| What are the Labile cell examples: | Bone marrow, gut epithelium, skin, hair follicles, and germ cells |
| Never go to G0, divide with a short G1 | Labile cells |
| Which type of cells are the ones most affected by Chemotherapy? | Labile cells |
| What occurs in the Rough Endoplasmic Reticulum (RER)? | Site of synthesis of secretory proteins and of N-linked oligosaccharide addition to many proteins. |
| What are the two main events that occur in the RER? | 1. Synthesis of secretory proteins 2. N-linked oligosaccharide addition to many proteins |
| What is the Nissl bodies? | RER in neurons |
| What is the function of Nissl bodies? | Synthesize peptide neurotransmitters for secretion |
| What are the "free ribosomes"? | Unattached to any membrane; site of synthesis of cytosolic and organellar proteins |
| What are some common cells rich in RER? | 1. Mucus-secreting goblet cells of the small intestine 2. Antibody-secreting plasma cells |
| What is the function of Smooth endoplasmic reticulum (SER)? | Site of steroid synthesis and detoxification of drugs and poisons |
| Which type of endoplasmic reticulum lacks of surface ribosomes? | Smooth |
| Which are some common cells rich in SER? | 1. Liver hepatocytes 2. Steroid hormone-producing cells of the adrenal cortex and gonad |
| What is the function of the Golgi? | Distribution center for proteins and lipids form the ER to the vesicles and plasma membrane |
| What are important tagging actions in the Golgi? | 1. Modifies N-oligosaccharide on Asparagine 2. Adds O-oligosaccharide on serine and threonine 3. Adds mannose-6-phosphate to proteins for trafficking to lysosomes. |
| What are Endosomes? | Sorting centers for material from outside the cell or from the Golgi |
| What is the function of Endosomes? | Sending material from outside the cell or from the Golgi, to lysosomes for destruction or to the membrane/Golgi for further use |
| What is I-cell disease? | Inherited lysosomal storage disease |
| What is the cause of I cell disease? | Defect in N-acetylglucosaminyl-1-phosphotransferase --> failure of the Golgi to phosphorylate mannose residues on glycoproteins, which causes proteins to be secreted extracellularly instead going to lysosomes. |
| What organelle is defective or malfunctioning in I cell disease? | Golgi |
| What are the common features of I cell disease? | Coarse facial features, gingival hyperplasia, clouded corneas, restricted joint movements, claw hand deformity, kyphoscoliosis, and high plasma levels of lysosomal enzymes |
| Which specific residue is wrongly phosphorylated in I cell disease? | Mannose residues (decrease mannose-6-phosphate) |
| What is the Signal recognition particle (SRP)? | Abundan, cytosolic ribonucleoprotein that traffics proteins from the ribosome to the RER |
| What is the result of absent or defective SRP? | Proteins accumulate in the cytosol |
| What are three common vesicular trafficking proteins? | COP I, COP II, and Clathrin |
| Which vesicular trafficking protein has retrograde movement? | COP I |
| Going from the cis-Golgi to the ER means: | Retrograde movement by COP I |
| Which protein helps the protein going anterograde fashion, from ER to the cis-Golgi? | COP II |
| What vesicular trafficking protein help the movement form the trans-Golgi to the Lysosomes? | Clathrin |
| What are the 4 main actions of a Peroxisome? | 1. Beta oxidation of very-long-chain fatty acids (VLCFA) 2. Alpha-oxidation 3. Catabolism of branched-chain fatty acids, amino acids, and ethanol 4. Synthesis of cholesterol, bile acids, and plasmalogens |
| What organelle is defective in Zellweger syndrome? | Peroxisome |
| Which action of a Peroxisome is strictly a peroxisomal process? | Alpha-oxidation |
| What is the inheritance form of Zellweger Syndrome? | Autosomal recessive |
| What is the cause of Zellweger syndrome? | Mutated PEX genes |
| Clinical features of a Zellweger syndrome patient? | Hypotonia, seizures, hepatomegaly, and early death |
| What are common pathological conditions of defective Peroxisome? | Zellweger syndrome, Refsum disease, and Adrenoleukodystrophy. |
| Which Peroxisomal diseases are of AR inheritance? | Zellweger syndrome and Refsum disease |
| X-linked recessive disorder of B-oxidation. Dx? | Adrenoleukodystrophy |
| What disease is caused by a defective alpha oxidation process? | Refsum disease |
| What is the result of defective alpha oxidation in Refsum disease? | Phytanic acid is not metabolised to pristanic acid |
| What is the clinical features of Refsum disease? | Scaly skin, ataxia, cataracts/night blindness, shortening of 4th toe, epiphyseal dysplasia |
| What condition is to be suspected in case of VLCFA buildup in adrenal glands, white matter of brain, and testes? | Adrenoleukodystrophy |
| What is the role/ function of Proteasome? | Barrel-shaped protein complex that degrades damaged or ubiquitin-tagged proteins |
| What are some implications in an defective ubiquitin-proteasome system? | Cases of Parkinson disease |
| A network of protein fibers within the cytoplasm that supports cell structure, cell and organelle movement, and cell division. | Cytoskeletal elements |
| What is the main function of Microfilaments? | Muscle contraction and cytokinesis |
| What are examples of microfilaments? | Actin, and microvilli |
| What is the function of Intermediate filaments? | Maintain cell structure |
| What are some examples of intermediate filaments? | Vementin, desmin, cytokeratin, lamins, glial fibrillary acidic protein (GFAP), and neurofilaments |
| Vimentin is: | Intermediate filament that works to maintain cell structure |
| Cytokeratin is an _______________________ filament. | Intermediate |
| What is the main function of microtubules? | Movement and cell division |
| What are some important examples of Microtubules? | Cilia, flagella, mitotic spindle, axonal trafficking, and centrioles |
| Description of outer structure of a microtubule. | Cylindrical; composed of array of polymerized heterodimers of a- and B-tubulin |
| What is bound to each dimer in a microtubule? | 2 GTP |
| What are Molecular motor proteins function? | Transport cellular cargo toward opposite ends of microtubule |
| What are the two most important molecular motor proteins? | Dynein and Kinesin |
| How is the transport of Dynein? | Retrograde to microtubule (+ --> -) |
| Anterograde to microtubule transport is done by ______________. | Kinesin |
| What are some drugs that act on microtubules? | 1. Mebendazole 2. Griseofulvin 3. Colchicine 4. Vincristine/Vinblastine 5. Paclitaxel |
| What are the anticancer medications that act on microtubules? | Vincristine/Vinblastine and Paclitaxel |
| Which anthelmintic MOA is on the microtubule structure? | Mebendazole |
| What antifungal is used to inhibit microtubule formation? | Griseofulvin |
| What structure is targeted in the use of Colchicine? | Microtubule |
| 9 doublet + 2 singlet arrangement of microtubules describe the structure of _______________. | Cilia |
| How is the basal body of cilia formed? | 9 microtubule triplets with no central microtubules |
| What is the function of Axonemal dynein? | ATPase that links peripheral 9 doublets and causes bending cilium by differential sliding of doublets |
| What structures enable coordinated ciliary movement? | Gap junctions |
| What is the cause of Kartagener syndrome? | Immotile cilia due to a dynein arm defect |
| What is another name for Kartagener syndrome? | Primary ciliary dyskinesia |
| What is the main reproductive affection of Kartagener in both, male and females? | Infertility |
| Why the infertility in males with Kartagener syndrome? | Immotile sperm |
| Dysfunctional fallopian tube cilia, leading to infertility is a common feature of _________________________ syndrome. | Kartagener syndrome |
| What are some clinical developments or features seen in Kartagener syndrome, besides infertility? | Bronchiectasis, recurrent sinusitis, chronic ear infections, conductive hearing loss, and situs inversus |
| Dextrocardia on CXR. Suspect Dx? | Kartagener syndrome |
| The Na-K+ ATPase is located at: | Plasma membrane with ATP side on cytosolic side |
| In regards to the Sodium-Potassium pump, for every 3 Na+ that got out of ceh cell, how many K+ come into cell? | 2 |
| The exit or "pumped out" of 3 Na+ by the Na+K+ ATPase, is called: | Pump phosphorylated |
| When the Na+/K+ pump is referred as dephosphorylated, it indicates the: | 2K+ ions coming into the cell |
| Which cardiac glycoside MOA is to inhibit the binding of K+ to in the Na/K pump? | Ouabain |
| Which cardiac glycoside directly inhibit the Sodium Potassium pump? | Digoxin |
| What is the most abundant protein in the human body? | Collagen |
| What is the main function of Collagen? | Organizes and strengthens extracellular matrix |
| What type of collagen is the most common? | Type I |
| What condition is due to a defective type I collagen? | Osteogenesis imperfecta type I |
| What tissues are made of Type I collagen? | Bone, Skin, Tendon, dentin, fascia, cornea, and late wound repair |
| What tissues are of type II collagen? | Cartilage, vitreous body, and nucleus pulposus |
| What type of collagen makes up Reticulin- skin, blood vessels, uterus, fetal tissue, and granulation tissue? | Type III |
| What is made with type IV collagen? | Basement membrane, basal lamina, and lens |
| Which type of collagen is found in the cornea? | Type I |
| Cartilage is type ___ collagen. | II |
| Blood vessels type _____ collagen. | III |
| Bone, Skin, and tendon are of type ____ collagen. | I |
| What condition is associated to defective type 3 collagen? | Vascular type Ehlers-Danlos syndrome |
| Which type of Ehlers-Danlos syndrome is due to defective type III collagen? | Vascular |
| Type IV collagen is attacked by autoantibodies in which common condition? | Goodpasture syndrome |
| What pathology is seen with defictive Type IV collagen? | Alport syndrome |
| Which two disease are associated by defective/damaged Type IV collagen? | Alport syndrome and Goodpasture syndrome |
| If Collagen type IV is defective, it most likely refers to which condition? | Alport syndrome |
| Which is an autoimmune disease of collagen IV? | Goodpasture syndrome |
| What collagen IV structure is damaged in Alport syndrome? | Basement membrane |
| Where does synthesis of collagen occurs? | Rough Endoplasmic Reticulum |
| Which organelle contains preprocollagen accumulation? | Rough Endoplasmic Reticulum |
| Gly-X-Y (X and Y are proline or lysine). | Preprocollagen |
| What is the best approximate fraction of Glycine content in preprocollagen? | 1/3 |
| In Collagen synthesis which is the order in which reaction occurs FIRST, hydroxylation or glycosylation? | Hydroxylation occurs first |
| What is required in order for Hydroxylation of collagen in the RER to occur? | Vitamin C |
| What is scurvy? | Vitamin C deficiency |
| A person with vitamin C deficiency will have an impaired __________ step in the synthesis of collagen. | Hydroxylation |
| What is hydrolyzed in the hydroxylation step of Collagen synthesis? | Proline and Lysine residues |
| What happens in the Glycosylation of collagen synthesis pathway? | Glycosylation of pro-a-chain hydroxylysine residues and formation of procollagen via hydrogen and disulfide bonds |
| What premature form of collagen is produced by Glycosylation step? | Procollagen |
| What step in collagen synthesis produces the triple helix of 3 collagen a-chains? | Glycosylation |
| Problems forming the triple helix result in development of: | Osteogenesis imperfecta |
| Specifically, Osteogenesis imperfecta is due to a defective ___________________ step in collagen synthesis. | Glycosylation |
| What form of collagen is exocytosed into extracellular space? | Procollagen |
| Defective cleavage of Procollagen leads to development of _____________________ syndrome. | Ehlers-Danlos |
| What is form by the cleavage of disulfide-rich terminal regions of procollagen? | Insoluble tropocollagen |
| What are two disease associated with improper collagen cross linking? | Ehlers-Danlos syndrome and Menkes Disease |
| What is the enzyme used to cross link tropocollagen? | Copper-containing lysyl oxidase |
| What is made by covalent lysine-hydroxylysine cross-linkage of many staggered tropocollagen molecules? | Collagen fibrils |
| What are the associated gene defects of Osteogenesis Imperfecta? | COLIA1 and COLIA2 |
| Osteogenesis imperfecta is seen clinically with what features? | - Multiple fractues with miniaml trauma - Blue sclerae - Tooth abnormalities (lack of dentin) - Hearing loss |
| What is the cause of hearing loss in Osteogenesis imperfecta? | Abnormal ossicles |
| Why are the teeth a target for Osteogenesis imperfecta? | Dentin is made of Collagen type I, and its deficit lead to easy wear of teeth |
| What is the treatment for OI? | Bisphosphonates to decrease risk of fracture |
| What is the MC form of inheritance seen in Osteogenesis imperfecta? | Autosomal dominant |
| What is the definition of Ehlers-Danlos syndrome? | Faulty collagen synthesis causing hyperextensible skin, hypermobile joints, and tendency to bleed |
| What are some serious complications and associations with Ehlers-Danlos syndrome? | Joint dislocation, Berry and Aortic aneurysms, and organ rupture |
| What is the MC type of Ehlers-Danlos syndrome? | Classical type (joint and skin) due to mutation in type V collagen |
| Deficiency type III procollagen. Dx? | Vascular Ehlers-Danlos syndrome |
| What is Menkes disease? | XR connective tissue disease caused by impaired copper absorption and transport due to defective Menkes protein (ATP7A) |
| What is ATP7A? | Menkes protein |
| The lack of copper leads to a decrease in function of what collagen synthesis enzyme? | Lysyl oxidase |
| What is the clinical manifestation of Menkes disease? | Brittle, "kinky" hair, growth retardation and hypotonia |
| What is elastin? | Stretchy protein within skin, lungs, large arteries, elastic ligaments, vocal cords, ligamenta flava. |
| What enzyme can break Elastin? | Elastase |
| What common enzyme or protein inhibits the actions of Elastase? | alpha-1-antitrypsin (ATT) |
| What is the result of Alpha-1-antitrypsin deficiency? | Unopposed elastase activity, leading to development of COPD |
| What chromosome is affected in Marfan syndrome? | Chromosome 15 |
| AD disorder of connective tissue affecting the skeleton, heart, and eyes, with mutated FBN1 gene. Dx? | Marfan syndrome |
| What are common vascular complications of Marfan syndrome? | Cystic medial necrosis of aorta; aortic root aneurysm rupture or dissection; mitral valve prolapse |
| Description of necrosis seen in Marfan syndrome? | Cystic medial necrosis of aorta |
| How is the lens subluxation in patients with Marfan syndrome? | Upward and temporally |
| How is the lens subluxation in patients with homocystinuria? | Downwards and medially |
| What syndrome is associated with a defective fibrillin protein? | Marfan syndrome |
| What is the sheath around elastin called? | Fibrillin |
| What are the fat soluble vitamins? | A, D, E, K |
| Where are all fat soluble vitamins absorbed? | Ileum and Pancreas |
| Why are fat soluble vitamins more toxic than water soluble? | They accumulate in the fat |
| What conditions can cause Fat-soluble vitamin deficiencies? | 1. Malabsorption syndromes 2. Mineral oil intake |
| What are common examples of Malabsorption syndromes that result in Fat Soluble vitamin deficiencies? | Cystic fibrosis and Celiac disease |
| Of all the water soluble vitamins, which are the only two that get store temporarily in the body? | Cobalamin (Vit B12) in liver for 3~4 years, and Folate (Vit B9) in liver for 3~4 months |
| What are common symptoms seen in B-complex deficiencies? | Dermatitis, glossitis, and diarrhea |
| What is the common name of Vitamin B1? | Thiamine |
| What is the coenzyme associated with Thiamine? | Thiamine pyrophosphate (TPP) |
| Coenzymes associated with Vitamin B2? | FAD and FMN |
| What is another name of Vitamin B2? | Riboflavin |
| Niacin = | Vitamin B3 |
| What coenzyme is associated with Niacin? | NAD+ |
| B5: | Pantothenic acid; CoA (coenzyme) |
| What is the coenzyme of Pyridoxine? | PLP |
| Pyridoxine = | Vitamin B6 |
| What is the common name for Vitamin B7? | Biotin |
| How else is Vitamin B9 and Vitamin B12, named, respectively? | Folate and Cobalamin, respectively. |
| Functions of Vitamin A? | 1. Antioxidant 2. Constituent of visual pigments (retinal) 3. Essential for normal differentiation of epithelial cells into specialized tissue 4. Prevents squamous metaplasia |
| What type of tissue alteration or modification is prevented by Vitamin A? | Squamous metaplasia |
| What cells are greatly affected by Vitamin A aid in epithelial cell differentiation? | Pancreatic cells and Mucus-secreting cells |
| What are some old uses for Vitamin A? | 1. Measles 2. Acute Promyelocytic leukemia (APL) |
| What types of Vitamin A are often used in medicine? | Retinal, retinol, and retinoic acid |
| Which form of vitamin A is used to treat wrinkles and acne? | Topical retinol |
| In which products is vitamin A naturally found? | Liver and leafy vegetables |
| What can be used to treat severe cystic acne? | Oral isotretinoin |
| What are symptoms of Vitamin A deficiency? | 1. Night blindness 2. Dry, scaly skin (Xerosis cutis) 3. Bitot spots 4. Corneal degeneration 5. Immunosuppression |
| What is xerosis cutis? | Dry, scaly skin most likely due to Vitamin A deficiency |
| When are Bitot spots commonly seen? | Vitamin A deficiency |
| What are Bitot spots? | Keratin debris; foamy appearance on conjunctiva |
| What is Keratomalacia? | Corneal degeneration |
| What are the teratogenic effects of Vitamin A? | Cleft palate and cardiac abnormalities |
| Chronic toxicity of Vitamin A excess is clinically seen with: | Alopecia, dry skin, hepatic toxicity and enlargement, arthralgias, and idiopathic intracranial hypertension |
| Thiamine requires what cofactor? | Thiamine pyrophosphate (TPP) |
| What are the 4 enzymes that require Thiamine and TPP? | 1. Branched-chain ketoacid dehydrogenase 2. a-Ketoglutarate dehydrogenase (TCA cycle) 3. Pyruvate dehydrogenase 4. Transketolase |
| What is "linked" by Pyruvate dehydrogenase? | Glycolysis to TCA cycle |
| A deficiency in vitamin _______ will lead to a decrease action of Pyruvate dehydrogenase. | B 1 |
| Which water soluble vitamin is given first to alcoholic patients in order to prevent Wernicke encephalopathy? | Vitamin B1 |
| How is vitamin B1 diagnosis made? | Increase in RBC transketolase activity following vitamin B1 administration |
| What are some conditions seen with Vitamin B1 deficiency? | 1. Wernicke encephalopathy 2. Korsakoff syndrome 3. Wernicke-Korsakoff syndrome 4. Dry beriberi 5. Wet beriberi |
| Describe the classic triad of Wernicke encephalopathy? | Confusion, Ophthalmoplegia, and ataxia |
| Acute, life-threatening, neurologic condition due to Thiamine deficiency? | Wernicke Encephalopathy |
| Describe Korsakoff syndrome | Amnestic disorder due to chronic alcohol consumption; presents with confabulation, personality changes, and permanent memory loss. |
| How is the memory loss Korsakoff syndrome described as? | Permanent |
| What is damaged in Wernicke-Korsakoff syndrome? | Medial dorsal nucleus of thalamus, and mammillary bodies |
| What is the clinical presentation of Dry beriberi? | Polyneuropathy and symmetric muscle wasting |
| What are cardiac involvement seen in Wet beriberi? | High-output cardiac failure (dilated cardiomyopathy), edema |
| The cofactors of Vitamin B2 serve in ______________ reactions. | Redox |
| What are the associated cofactors of Riboflavin? | FAD and FMN |
| What is the most important redox reaction in which FAD and FMN are involved? | Succinate dehydrogenase reaction in the TCA cycle. |
| Riboflavin deficiency is seen with: | Cheilosis and Corneal vascularization |
| What is Cheilosis? | Inflammation of lips, scaling and fissures at the corners of the mouth |
| Vitamin B3 is derived from ________________. | Tryptophan |
| What other B-vitamins are required for the formation of Vitamin B3? | Vitamin B2 and B6 |
| What is a common condition treated with Niacin? | Dyslipidemia |
| How many ATP molecules are seen with Vitamin B3? | 3 ATP |
| What vitamin deficiency causes Pellagra? | Vitamin B3 deficiency |
| What causes of Pellagra? | 1. Severe Vitamin B3 deficiency 2. Malignant carcinoid syndrome 3. Isoniazid |
| Why does carcinoid syndrome develops Pellagra? | Increases tryptophan metabolism |
| What is Hartnup disease? | AR; deficiency of neutral amino acid (tryptophan) transporters in Proximal renal tubular cells and on enterocytes |
| What are the main symptoms of Pellagra? | Diarrhea, Dementia, and Dermatitis |
| What is the description of Dermatitis seen with Pellagra? | C3/C4 dermatome circumferential "broad collar" rash, hyperpigmentation of sun-exposed limbs |
| What are some effects of Niacin in excess? | Facial flushing by prostaglandin, hyperglycemia, and hyperuricemia |
| What is different of the Facial flushing seen with Pellagra? | It is due to prostaglandin, and not histamine |
| What can be administer to avoid Niacin-induced facial flushing? | Aspirin with Niacin |
| Podagra is often seen with excess of Vitamin ______. | B3 |
| What is an essential component of CoA? | Vitamin B5 |
| What are some important features seen with Vitamin B5 deficiency? | Dermatitis, enteritis, alopecia, and adrenal insufficiency |
| What does cofactor PLP stand for? | Pyridoxal phosphate |
| For which reactions is PLP important: | - Transamination - Decarboxylation reactions -Glycogen phosphorylase |
| What molecules, proteins and enzymes require Vit B6 for its synthesis? | Glutathione, Cystathionine, heme, niacin, histamine, and Neurotransmitters |
| Which neurotransmitters require Vit B6 for their synthesis? | Serotonin, Epinephrine, Norepinephrine, dopamine, and GABA |
| What is clinically presented in a patient with Vitamin B6 deficiency? | 1. Convulsions, hyperirritability 2. Peripheral Neuropathy 3. Sideroblastic anemia |
| What kind of anemia is seen with pyridoxine deficiency? | Sideroblastic anemia due to impaired hemoglobin synthesis and iron excess |
| What conditions predispose a patient to develop peripheral neuropathy due to Vitamin B6 deficiency? | Deficiency inducible by isoniazid and oral contraceptives |
| Biotin is a cofactor for carboxylation enzymes which add --> | 1-carbon group |
| What are 3 common enzymes that use biotin as a cofactor? | 1. Pyruvate carboxylase 2. Acetyl-CoA carboxylase 3. Propionyl-CoA carboxylase |
| What is a rare cause of biotin deficiency? | Excessive ingestion of raw egg whites |
| What is the function of of Vitamin B9? | Coenzyme for 1-carbon transfer/methylation reactions |
| Where is folate is absorbed? | Jejunum |
| What kind of anemia is seen with Folate deficiency? | Macrocytic, megaloblastic anemia |
| What drugs are associated in precipitating folate deficiency? | Phenytoin, sulfonamides, and MTX |
| What are the labs seen Macrocytic, megaloblastic anemia due to folate deficiency? | Increased homocysteine, normal methylmalonic acid levels |
| Vitamin B12 serves as a cofactor to which two main enzymes: | 1. Methionine synthase 2. Methylmalonyl-CoA mutase |
| Vitamin B12 transfers ________ groups. | CH3 |
| What is the difference anemia between Folate and Cobalamin deficiency? | Cobalamin deficiency anemia is accompanied with neurological symptoms |
| What are some causes of Cobalamin deficiency? | - Malabsorption - Lac of intrinsic factor -Absence of terminal ileum - Drugs -Insufficient intake |
| What are common malabsorption conditions that cause a deficiency in Vitamin B12? | Sprue, enteritis, Diphyllobothrium latum, achlorhydria, bacterial overgrowth, alcohol excess |
| Pernicious anemia is the MCC of: | Megaloblastic anemia due to lack of intrinsic factor |
| Which antibody is diagnostic of Pernicious anemia? | Anti-intrinsic factor antibodies |
| Vitamin C is necessary for: | - Facilitates iron absorption by reducing Fe2+ state - Hydroxylation of proline and lysine in collagen synthesis - Dopamine B-hydroxylase |
| What is the clinical characteristics of Scurvy? | Swollen gums, easy bruising, petechiae, hemarthrosis, anemia, poor wound healing, perifollicular and subperiosteal hemorrhage, "corkscrew" hair |
| What is the name of D3? | Cholecalciferol |
| What is the name of D2? | Ergocalciferol |
| What is the active form of Vitamin D? | 1, 25 -(OH)2 D3 (calcitriol) |
| In which organ converts Vitamin D into active form? | Kidney |
| Functions of Vitamin D: | 1. Increase intestinal absorption of Ca2+ and phosphate 2. Increase bone mineralization at low levels 3. Increase bone resorption at higher levels |
| Condition of children due to vitamin D deficiency. | Rickets |
| What is the condition of vitamin D deficiency in adults? | Osteomalacia |
| What kind of disease are seen with increased levels of Vitamin D? | Granulomatous diseases |
| What is the function of Vitamin E? | Antioxidant by protein RBCs and membranes from free radical damage |
| What are some clinical manifestations of Vitamin E deficiency? | Hemolytic anemia, acanthocytosis, muscle weakness, posterior column and spinocerebellar tract demyelination |
| What is the risk of Vitamin E excess? | Risk of enterocolitis in infants |
| How is the difference in neurologic symptoms in Vitamin E deficiency and Cobalamin deficiency? | Vitamin E deficiency does not causes megaloblastic anemia |
| What vitamin ingestion may enhance the effects of Warfarin? | Vitamin E |
| What are some examples of Vitamin K? | Phytomenadione, phylloquinone, phytonadione, and menaquinone. |
| What is the function of of Vitamin K? | Activated by epoxide reductase to the reduced form, which is a cofactor for the gamma-carboxylation of glutamic acid residues on various proteins required for blood clotting. |
| Where is vitamin K synthesized? | Intestinal flora |
| What clotting factors require vitamin K? | II, VII, IX, X, and proteins C and S. |
| What medication inhibits the synthesis of vitamin K? | Warfarin |
| How are the changes of PT, aPTT, and BT in cases of vitamin K deficiency? | Increased PT and PTT, and a normal BT. |
| Why is a vitamin K injection given at birth? | To prevent hemorrhagic disease of the newborn |
| What are the functions or needs to Zinc? | 1. Mineral essentia. for the activity of 100+ enzymes 2. Formation of zinc fingers (transcription factor motif) |
| What are the clinical manifestations of Zinc deficiency? | Delayed wound healing, suppressed immunity, hypogonadism, decreased adult hair, dysgeusia, anosmia, acrodermatitis enteropathica |
| Dysgeusia, anosmia and cutaneous rash is presented with what kind of mineral deficiency? | Zinc |
| What are two major conditions due to a deficiency in protein-energy malnutrition? | Kwashiorkor and Marasmus |
| What are the main clinical features of Kwashiorkor? | Malnutrition, Edema, Anemia, fatty Liver, and Skin lesions (hyperkeratosis, and dyspigmentation) |
| Why is edema in Kwashiorkor? | Decrease in plasma oncotic pressure |
| Small child with swollen abdomen and skin lesions. Dx? | Kwashiorkor |
| What protein malnutrition is seen without edema? | Marasmus |
| What is the main symptoms in Marasmus? | Muscle wasting |
| What is the antidote of overdose of Methanol or Ethylene glycol? | Fomepizole |
| What enzyme is inhibited by Fomepizole? | Alcohol dehydrogenase |
| Disulfiram inhibits which enzyme? | Acetaldehyde dehydrogenase |
| What substance is accumulated that contributes to hangover symtposm? | Acetaldehyde |
| What is the limiting reagent of Ethanol metabolism? | NAD+ |
| What is the kinetics of Alcohol dehydrogenase? | Zero-order kinetics |
| What ratio is increased in Ethanol metabolism? | NADH: NAD+ |
| Which reaction of glycolysis, produces NAD+? | Pyruvate -----> Lactate |
| Which TCA cycle reaction of NADH --> NAD+? | Oxaloacetate ----> Malate |
| What are some effects of Ethanol metabolism? | 1. Pyruvate -->lactate (lactic acidosis) 2. Oxaloacetate --> malate (prevents gluconeogenesis --> fasting hypoglycemia) 3. Dihydroxyacetone phosphate --> glycerol-3-phosphate (G3P) --> hepatosteatosis |
| What cycle is disfavored by an increased NADH: NAD+? | TCA cycle |
| What metabolic processes occur exclusively in the Mitochondria? | 1. Fatty acid oxidation (B-oxidation), 2. Acetyl-CoA production 3. TCA cycle 4. Oxidative phosphorylation 5. Ketogenesis |
| What are exclusive cytoplasmic metabolic processes? | 1. Glycolysis 2. HMP shunt 3. Synthesis of steroids (SER), proteins (ribosomes, RER), fatty acids, cholesterol, and nucleotides |
| What 3 metabolic process occur in the mitochondria and the cytoplasm? | 1. Heme synthesis, 2. Urea cycle 3. Gluconeogenesis |
| What is a Kinase? | Enzyme that catalyzes the transfer of phosphate group from a high-energy molecule to a substrate |
| What is the function of a Phosphorylase? | Adds inorganic phosphate onto a substrate WITHOUT using ATP |
| What is an Phosphatase role? | Removes phosphate group from substrate |
| Catalyzes oxidation -reduction (redox) reactions? | Dehydrogenase |
| Adds hydroxyl group (-OH) onto substrate | Hydroxylase |
| What is a common example of an Hydroxylase? | Tyrosine hydroxylase |
| Pyruvate carboxylase is an _________________________. | Carboxylase |
| What is the function of a Carboxylase? | Transfers CO2 groups with the help of biotin |
| What is needed in order to work any carboxylase? | Biotin |
| What is the main action of an mutase? | Relocates a functional group within a molecule |
| Joins to molecules together using a source of energy? | Synthase/synthetase |
| What is the MC high-energy molecule used by a kinase? | ATP |
| Fructose-1, 6-bisphosphatase is an example of ________________. | Phosphatase |
| What is the Rate limiting enzyme of Glycolysis? | Phosphofructokinase-1 (PFK-1) |
| What are stimulators (positive regulators) of Glycolysis? | AMP, and fructose-2, 6-bisphosphate |
| ATP and citrate are: | Inhibitors of Glycolysis |
| What is the rate limiting step of Gluconeogenesis? | Fructose-1, 6- bisphosphatase |
| What is a common negative regulator of Gluconeogenesis? | Fructose-2, 6-bisphosphate |
| What is the rate limiting enzyme of TCA cycle? | Isocitrate dehydrogenase |
| The enzyme is an Glycogen synthase is the rate limiting enzyme of ___________________. | Glycogenesis |
| What is the rate-limiting enzyme of glycogenolysis? | Glycogen phosphorylase |
| G6PD is the rate limiting enzyme is of __________________. | HMP shunt |
| What enzyme is rate limiting of De novo pyrimidine synthesis? | Carbamoyl phosphate synthetase II |
| PRPP is the rate limiting enzyme of ______________________. | De novo purine synthesis |
| What is a positive regulator of Urea cycle? | N-acetylglutamate |
| What is the rate limiting enzyme of Urea cycle? | Carbamoyl phosphate synthetase |
| What is the rate limiting enzyme of Fatty acid synthesis? | Acetyl-CoA carboxylase |
| Fatty acid oxidation uses ________________________ as its rate limiting enzyme. | Carnitine acyltransferase I |
| Cholesterol synthesis rate limiting enzyme is? | HMG-CoA reductase |
| HMG-synthase is the rate limiting enzyme of which metabolic process? | Ketogenesis |
| Enzyme deficiency of mild Galactosemia? | Galactokinase |
| What enzyme is deficient in Severe Galactosemia? | Galactose-1-phosphate uridyltransferase |
| What is the defective enzyme in von Gierke disease? | Glucose-6-phosphatase |
| Deficient Fructokinase. Dx? | Essential fructosuria |
| What condition is due to Aldolase B deficiency? | Fructose intolerance |
| What aerobic shuttle is used by the heart and liver in ATP production? | Malate-Aspartate shuttle |
| How many ATP molecules are produced by each glucose molecule via the Malate-aspartate shuttle? | 32 |
| What "shuttle" is used in muscle in glycolysis in production of ATP? | Glycerol-3-phosphate shuttle |
| What is the net ATP production by aerobic glycolysis via the Glycerol-3-phosphate shuttle? | 30 |
| How many ATP molecules / glucose molecule via the anaerobic glycolysis? | 2 net ATP |
| What metal (poison) causes glycolysis to produce zero net ATP? | Arsenic |
| What are the most common Universal electron acceptors? | 1. Nicotinamides (NAD+, NADP+) 2. Flavin nucleotides (FAD+) |
| FAD+ comes from vitamin ________. | B2 |
| NAD+ and NADP+ comes from vitamin _____. | B3 |
| What processes or enzymes use NADPH? | 1. Anabolic processes 2. Respiratory burst 3. Cytochrome P-450 system 4. Glutathione reductase |
| NAD+ is generally used in ____________ processes to carry reducing equivalents away as NADH. | Catabolic |
| NADPH is a product of ______________________. | HMP shunt |
| What kinases are used to phosphorylation of glucose to yield Glucose-6-phosphate? | Hexokinase and Glucokinase |
| Hexokinase is used in most tissues except for: | Liver and Pancreatic B-cells |
| Which cells use Glucokinase? | Liver, B-cells of pancreas |
| What is the role or function of Glucokinase at high glucose concentration? | Helps to store glucose in liver |
| Which has higher affinity, Hexokinase or Glucokinase? | Hexokinase |
| While Hexokinase has a higher affinity, it also has a ________ capacity. | Lower |
| What protein reverses the actions of FBPase-2 and PFK-2? | Protein kinase A |
| In the regulation of Fructose-2, 6-bisphosphate, which bifunctional enzyme is active in fasting state? | FBPase-2 |
| PFK-2 enzyme is active in which state? | Fed state |
| Increased activity of FBPase-2 leads to overall increase of __________________________. | Gluconeogenesis |
| Upregulation or activity of PFK-2 followed by PFK-1, causes a preference to __________________, metabolic process activity. | Glycolysis |
| What enzyme is used to convert Fructose-1, 6-BP into Fructose-6-phosphate? | FBPase-1 |
| Increased glucagon is seen in _______________ state. | Fasting |
| Increased levels of insulin are seenin __________________ state. | Fed |
| More glycolysis and less gluconeogenesis is seen in _______ state. | Fed |
| Induced less glycolysis and more gluconeogenesis is seen in ________ state. | Fasting |
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