| Question | Answer |
| Cells | basic living, structural, and functional units of the body |
| Eukaryotic cells | have a defined nucleus
evolved from prokaryotic cells |
| ____ is a necessity in cells. | Specialization |
| 8 Components of Typical Cells | -plasma membrane
-cytoplasmic matrix
-mitochondrion
-nucleus
-endoplasmic reticulum
-golgi apparatus
-lysosomes
-peroxisomes |
| Plasma membrane is composed of these 2 structures | phospolipids
proteins |
| The plasma membrane has ____ and _____ type of layers | hydrophobic
hydrophilic |
| Phospholipids | combination of phosphoglycerideas & phosphingolipids |
| What gives the components of the plasma membrane their functions? | proteins |
| What is the geometry of the plasma membrane? | asymmetrical |
| What type of structures does the membrane contain? (ex. solid or not) | fluid |
| What makes the plasma membrane different from other membranes? | greater CHO and cholesterol content |
| In the plasma membrane, there is a ___ bilayer concenpt. | lipid |
| What is the glycocalyx? | it is the sugar coat on a cell that protects the cell and plasma membrane from bacteria |
| Glycoproteins | important integral membrane proteins in the lipid bilayer of the plasma membrane which plays a role in cell-cell interactions |
| 2 types of membrane proteins | integral
peripheral |
| Integral membrane proteins | in the lipid bilayer |
| Peripheral membrane proteins | through entire membrane and stick out |
| Cytoplasmic Matrix | cytoskeleton providing:
-locomotion
-transport
-structural support |
| 3 components of cytoskeleton | -microtubules
-microfilaments
-intermediate filaments |
| What is the fluid that surrounds the cytoplasmic matrix? | cytoplasm |
| Microtubules | provide mechanical support for the cell to determine its shape |
| Microfilaments | "assembled" or "disassembled" for cell locomotion, changes in cell shape, phagocytosis, etc |
| Intermediate filaments | provide mechanical strength to cells that go thru more stress such as neurons, muscle cells, and epitheial cells |
| Is there communication between cells in the cytoplasmic matrix? | yes, intracelluar |
| What does the cytoplasmic matrix transfer? | DNA/ RNA |
| Structural arrangement of the cytoplasmic matrix influences these metabolic pathways | glycolysis
hexose monophosphate shunt (pentose phosphate pathway)
glycogenesis and glycogenolysis
fatty acid sythesis |
| Fatty acid synthesis | production of nonessential, unsaturated fatty acids |
| Glycogenesis and glycogenolysis | glycogen syntheis and the breakdown f glycogen |
| Hexose monophosphate pathway | generates NADPH and pentoses |
| Glycolysis | metabolic pathway that converts glucose into pyruvate. The free energy released used to form ATP and NADH |
| Role of mitochondrion | energy production and oxygen use site |
| What surrounds the mitochondria? | double membrane called the mitochondrial membrane |
| Mitochondrial membrane (outer & inner) | outer: porous
inner: selectively permeable site of electron transport chain |
| Mitochondria try to increase their surface area why? | it increases the rate of reactions |
| Mitochrondrial matrix is the site of what? | TCA cycle
fatty oxidation synthesis |
| Mitochondrial matrix contains ____ so organelles can ____. | DNA;
divide |
| Mitochondrial DNA is _____ ONLY. | maternal |
| All cells have ____, except _____. | mitochondria;
erythrocytes (need glycolysis) |
| Mitochondria have what? | separate DNA so that they can create more or less of them based on needs of the cells |
| Nucleus | largest organelle |
| Nucleus is surrounded by? | nuclear envelope |
| Nucleus contains? | DNA |
| Cell genome | entire set of genetic information |
| Nucleoli | condensed chromatin |
| Nucleus is the site of? | DNA replication |
| In the nucleus, ____ synthesis occurs. | protein;
followed by transcription, translation, and elongation |
| Nucleus contains these acids | nucleic acids |
| Nucleus holds these 2 genetic materials that are important to chromosomes | DNA and RNA |
| Within the nucleus, macromolecules are formed from units of ____/_____. | nucleotides/bases |
| Which nucleotides/ bases are found in both DNA and RNA? | adenine, guanini, and cytocine (A, G, and C) |
| Which nucleotide/ base is found only in RNA? | uracil (U) |
| Which nucleotide/base is found only in DNA? | Thymine (T) |
| In DNA/ RNA, how do the nucleotides/ bases come together? | by complementary base pairing |
| What are the base pairings? | ex. g-C, A-U or T. |
| In the nucleus, cell replication occurs. What is this? | DNA unravels and nucleotides are added to each strand to make 2 sets |
| In the nucleus, cell transcription occurs. What is this? | mRNA created from sequence of one DNA strand (sense strand)
use of genes (codes for specific protein)
use of introns and exons |
| Genes | code for a specific protein |
| Introns | (transcription)
intervening sequences that help from proteins |
| Exons | no posttranscriptional processing
helps to form protein |
| There are parts of the DNA that aren't ____. | Coding |
| Describe the process of translation | -mRNA codes fro amino acid sequence to from protein
-mRNA is synthesized in nucleus, then moves to the RER
-codons assist in this process by coding for amino acids with the 3 base sequences
-tRNA brings amino acids to mRNA on ribosomes |
| Codons | 3-base sequences that code for amino acids |
| How do different characteristics of amino acids affect codons? | They form with the codons and perform different functions |
| After amino acids (AAs) are postioned, ____ bonds form between them. | peptide |
| Elogation | peptide bonds form in between the positioned amino acids. |
| Are all genes expressed in specialized cells of a given organ expressed? | no! only a few |
| "Nonsense" codon | signals end of protein (termination or stop codon) |
| Endoplasmic Reticulum | network of membranous channels used to communicate from innermost part of cell to exterior |
| What are the types of ER? | rough ER
smooth ER
sarcoplasmic retitulum |
| Rough ER | (studded with ribosomes)
protein syntheisis |
| Smooth ER | lipid synthesis |
| Sarcoplasmic reticulum | (in muscle)
calcium ion pump |
| Golgi Apparatus | protein trafficking and sorting |
| Golgi Apparatus is made up of? | 4-8 cisternae (stacks) |
| What type of networks are at either end of the golgi apparatus? | tubular;
cis and trans network |
| Cis-Golgi Network | entrance |
| Trans-Golgi network | exit |
| What is the Golgi Apparatus connected to? | ER by transport vesices |
| Lysosomes & Peroxisomes | enzyme-filled organelles |
| Lysosomes | cell's digestive system, it recycles parts of the cell that's not needed anymore |
| Peroxisomes | site of oxidative catabolic reactions (digestion) |
| Lysosome functions | phagocytosis
autolysis
bone resoption
hormone secretion and regualtion |
| Peroxisome functions | oxidize fatty acids to acetyl CoA
amino acid catabolism
detoxifying reactions |
| What are the 3 types of cellular proteins? | -receptors
-transport proteins
-enzymes |
| Receptors | (on the cell membrane)
modify cell's response to environment |
| Transport proteins | (through cell membrane)
regulate flow in and out of cells |
| Enzymes | catalysts (excite a reaction |
| Ligands | molecular stimuli that attach to receptors |
| Types of receptors | bind to ligand and convert it to internal signal
serve as ion channels
internalize stimulus intact
-various responses when bonded or internalized |
| Example of internal chemical signal | 3', 5' -cyclic AMP |
| Ion channel example | receptor for acetylcholine |
| Internalization stimulus example | insulin, triodothyronine |
| Transport proteins may act as ___ or ___. | carriers or pumps |
| Transport proteins may provide ____ through which _____ diffuse. | pores;
molecules |
| What is the most studied ion pump? | sodium |
| The sodium/ potassium pump provides how much energy to maintain ATPase? | 30-40% |
| Catalytic Proteins | (enzymes)
how it functions depends on protein and prosthetic group or coenzyme
-these also have specificity |
| Based on availability of substrate and free energy, most catalytic proteins are ____. | reversible |
| Regulation of catalytic proteins | -covalent modification through hormone stimulation
-modulation of allosteric enzymes
-enzyme induction |
| Allosteric | those with another site |
| Enzyme induction | changes in concentrations of inducible enzymes (down or up regulated at the transcriptional level) |
| Examples of enzyme types | -oxidoreductases
-transferases
-hydrolases
-lyases
-isomerases
-ligases |
| Oxidoreductases | (enzyme type)
reactions in which one compound is oxidized, another reduced (oxidation-reduction reaction) |
| Transferases | functional group transferred from one substrate to another |
| Hydrolases | hydrolysis of carbon bonds (breakdown of carbon molecules) |
| Lyases | cleavage of C-C, C-S. and C-N bonds (no hydrolysis/ O-R) |
| Isomerases | interconversion of optical or geometric isomers (glycolysis; interconverting sugars) |
| Ligases | catalyze formation of C and other bonds (O, S, N, others)
*protein synthesis makes new bonds |
| Clinical Applications of Cellular Enzymes
-conditions for diagnostic suitability | -enzyme's degree of organ/tissue specificity
-steep concentration gradient of enzyme activity between cell and surroundings
-enzyme must function in cytoplasm
-enzyme must be stable |
| What happens when there is increased production of an enzyme? | -malignant disease
-results in tumor markers |
| Oncogenes | mutated genes that encode abnormal, mitosis-signaling proteins that cause unchecked cell division |
| Apoptosis | programmed cell death |
| What are potential mechanisms for apoptosis? | intracellular stimuli
-create DNA damage
-release of cytochrome c
extracellular stimuli
-tumor necrosis facotr family of hormones or agonists
oncosis (swelling of the cell |
| Apoptosis: intracellular stimuli | create DNA damage |
| Apoptosis: extracellular stimuli | tumor necrosis facotr family of hormones or agonists |
| Oncosis | cellular swelling |
| Why does Apoptosis occur? | To pthe spread of harmful effectsrevent |
| What is the major source of biological energy in cells? | ATP |
| ATP is needed for? | exertion
anabolism
active transport
transfer of genetic info |
| Active transport involves? | ion pumps |
| Where does biological energy come from? | chemical reactions
-macronutrients give energy
-transferred from one form to another |
| What are the units of energy used? | cal, kcal, J, kJ |
| What are the equivalents of calories to Joules and kilocalories to kiloJoules? | 1 cal= 4.18 J
1 kcal= 4.18 kJ |
| What type of broad chemical reactions are used to produce biological energy? | exothermic and endothermic |
| Activation Energy | energy to raise reactants to transition state |
| Can chemical reactions be reversed? | yes! most are reversible, but not all. |
| What role does high-energy phosphate have in cells? | provides energy storage |
| What do coupled reactions do? | help to transfer energy
(ex. phosphorylation) |
| Phosphorylation | adding phosphate to a reactions |
| What role do reduction potentials have? | standard reduction potential- tendency of compound to donate and recieve electrons |
| Where is energy used from? | from the bond |
| Nutrigenetics | detecting gene variants within an indiviual |
| Nutrigenomics | seeing how environmental factors have an effect on genes and their interactions to determine applications |
| Nutritional Epigenetics | study of changes in gene expression that do not inviolve changes in the nucleotide sequence or DNA
(ex. adding or subtracting a methyl group to see what happens to the DNA |
