Term | Definition |
Amino acid | composed of an amino group, an acidic carboxyl group, a hydrogen atom, and a side chain; they make up proteins |
Chiral | there are 4 different substituents attached to the alpha-carbon |
Enantiomers | non-superimposable mirror images |
Proteases | enzymes that degrade protein |
Two important amino acid modifications | hydroxylation and methylation |
Physiological pH | 6.5-8.0 |
Zwitterionic | having two charges, or dipolar |
Ampholytes | molecules that can act either as an acid or a base |
Henderson-Hasselbalch Equation | pH = pKa + log([A-]/[HA]) |
Isoelectric point | the pH at which a molecule carries no net electric charge |
pI (formula) | (pKa1+pKa2)/2 |
cathode | the negative electrode, where positive charges go towards |
anode | the positive electrode where negative charges towards |
electrophoresis | a technique of separating amino acids based on isoelectric points |
buffer | ability to resist changes in pH |
peptide linkage | an amide bond between amino acids |
polypeptide | a term used for any length of a polymer of amino acids |
oligopeptide | 10 or more amino acids linked together |
protein | 100 or more amino acids linked together, into a functional entity |
disulfide bonds | cysteine residues that are joined together covalently, through oxidation |
alpha helix | secondary structures of polypeptides stabilized by hydrogen bonding, and with 3.6 aa per turn, 1.5 angstroms vertical rise per turn, and 100 degrees rotation per turn |
beta sheet | secondary structure of polypeptides that occurs via hydrogen bonding between strands of polypeptide, connected by beta-turns |
heme group | a crevice within myoglobin and hemoglobin subunits that can bind to oxygen |
primary structure | the sequence of amino acids, and the location of disulfide bonds |
secondary structure | the spatial arrangement of amino acids that are close to one another |
tertiary structure | the spatial arrangement of amino acids that are far from one another and is determined by the primary structure |
quaternary structure | the spatial structure of various subunits |
enzymes | proteins that catalyze reactions in cells |
active site or catalytic site | the crevice that a substrate come into contact with where it is bound in such a way that the enzyme can do chemistry on it |
allosteric site | an alternate site on an enzyme where regulation can occur via binding |
aldehyde | a molecule in which the carbonyl group is terminal |
ketone | the molecule in which the carbonyl group is internal |
reference carbon | the chiral carbon in a monosaccharide that is farthest from the carbonyl carbon |
pyranose | six membered sugar ring |
furanose | five membered sugar ring |
anomer | cyclic sugars that differ only in the configuration of the C-1 carbon |
anomeric carbon | the carbon on a sugar ring that determines the alpha or beta form of the sugar ring |
beta sugar rings | the hydroxyl group is on the same side (drawn as a ring) as the CH2OH group |
alpha sugar rings | the hydroxyl group is on the opposite side (drawn as a ring) as the CH2OH group |
hemiacetal | a half acetal. One of the oxygens is still bonded to a hydrogen. |
Hemiketal | a half ketal. One of the oxygens is still bonded to a hydrogen. |
Tollen’s reagent | a reagent used to identify reducing sugars that will precipitate silver if they are present |
Benedict’s reagent | a reagent used to identify reducing sugars, in which case a brick-red precipitate will form |
Sugar with “ide” ending | the sugar is not a reducing sugar |
Acetal group | a fully oxidized aldehyde, where both oxygens are not bound to hydrogens |
Ketal group | a fully oxidized ketone, where both oxygens are not bound to hydrogens |
Saturated fatty acids | fatty acids with no double bonds and all single bonds |
Unsaturated fatty acids | fatty acids with specific double bonds |
Triacylglycerol | fatty acids esterified to a glycerol backbone |
Glycerophosopholipids | a glycerol backbone with two fatty acid chains and one phosphoryl group with another molecule attached to it |
Sphingolipids | lipids derived from amino alcohols |
Ceramide | the structural reside common to all sphingolipids |
Cerebroside | a ceramide with a monosaccharide attached to the C-1 carbon |
Sphingoglycolipids | sphingolipids with sugar attached |
Gangliosides | ceramide with several sugar residues attached. |
Progesterone | steroid hormone that prepares the uterine lining for implantation of an ovum, and the maintaining of endometrial lining of the uterus |
Cortisol | steroid hormone made and secreted from cells in the adrenal gland to increase both glycogen synthesis and gluconeogenesis |
Aldosterone | steroid hormone that increases readsorption of sodium ions |
Testosterone | steroid hormone that facilitates sperm maturation and promotes male secondary characteristics |
Estradiol | steroid hormone the control a number of female characteristics |
Nucleotides | molecules composed of a nitrogenous base, pentose sugar, and phosphoric acid |
Purines | nitrogenous bases with two rings, adenine and guanine |
Pyrimidines | nitrogenous bases with one ring, thymine, guanine, uracil |
Phosphodiester bond | an ester bond with a phosphate group in the middle |
Cell cycle | the sum of all events that occur between the completion of one cell division and the next |
Interphase of cell cycle | intermediate phase of cell cycle |
G1 phase of cell cycle | the first growth phase, where RNA and proteins are actively being synthesized, the centriole pairs separate |
S phase of cell cycle | synthetic phase, where the DNA is replicated once, and centrioles are replicated |
G2 phase of cell cycle | second growth phase, where the chromatin begins to condense |
Aster | starlike structure of microtubules that form during prophase of mitosis |
Centrosome | the region from which microtubules extend outwards during mitosis |
MTOC | the region from which microtubules extend outwards during mitosis |
Mitotic spindle | a structure involved in the separation of the chromosomes during anaphase |
Kinetochore | a specialized area closely associated with the centromere |
Reductive division | another name for what happens in meiosis I |
Leptotene | first part of prophase I in meiosis I where replicated chromosomes have started to condense |
Zygotene | second part of prophase I in meiosis I where homologous chromosomes begin to pari up logintudinally to prepare for crossing over |
Synapsis | the overlapping regions of chromosomes during crossing over |
Synaptonemal comlex | a specialized protine and RNA scaffold that facilitates crossing over |
Pachytene | the third part of prophase I in meiosis I where crossing over takes place |
Diplotene | the fourth part of prophase I in meiosis I where the chromosomes begin to pull apart. Human eggs are arrested at this stage during development |
Diakinesis | the fifth and last part of prophase I in meiosis I where the nuclear envelope breaks down and the homologous chromosomes are moving apart |
Micelles | spherical strcutures that are formed when enough phospholipids congregate together such that heads are outside and tails are inside |
Liposome | a lipid bilayer folded back on itself |
Lateral diffusion | phospholipids exchanging places in a single layer of the membrane |
Transverse diffusion | phospholipids moving from one lipid plane to another, very rare |
Glycolipids | membrane lipid attached to a carbohydrate, usually found on the exterior surface of the membrane |
Glycoproteins | membrane proteins attached with carbohydrates |
Uniport | transporter protein involved in facilitated diffusion of one type of solute molecule |
Symport | transporter protein involved in facilitated diffusion of two types of solute molecules going in the same direction |
Antiport | transporter protein involved in facilitated diffusion of two types of solute molecules going in opposite directions |
Permeases | protein transporters that allow for the movement of a solute across a membrane |
Primary active transport | active transport in which the energy source is ATP directly (Na/K pump) |
Secondary active transport | active transport in which the energy source or diving factor is an ionic gradient (Na/glucose transport) |
Endocytosis | invagination of a portion of the membrane in which the vesicle travels into the cell |
Endosomes | vesicles resulting from endocytosis |
Pinocytosis | endocytosis of liquids |
Phagocytosis | endocytosis of larger particulate matter |
Exocytosis | the export of molecules or liquid via vesicles |
Nucleoplasm | the mixture of chromatin and the aqueous phase of the nucleus |
Nucleolus | a highly organized region within the nucleus centered around certain chromosomes that are involved in ribosomal RNA synthesis |
Signal peptide | a short segment of a polypeptide indicating that a ribosome’s destination is to be on the ER |
Smooth ER functions | synthesis of the majority of cell’s membrane lipids, hydroxylation of toxins, catabolism of glycogen, regulate calcium concentrations |
Rough ER functions | post-translational modification of polypeptides |
Signal sequence | a sequence of amino acids at the N-terminus of a polypeptide which binds to an SRP |
Signal recognition particle | located in the cytoplasm, these direct the ribosome to the ER, and bind to to signal sequence receptors |
Signal sequence receptors | embedded in the ER membrane, which allow for docking of the SRP, which allows the ribosome to be anchored |
Signal peptidase | in the ER lumen, and degrades the signal sequence |
Golgi apparatus | a complex of flattened membraneous sacs called cisternae that are involved in chemical modification of a maturing protein |
Glycosylation | addition of carbohydrates |
Sulfation | addition of inorganic sulfates |
Proteolysis | reducing the size of the protein |
Lysosomes | vesicles originating from the membrane of the Golgi which contain hydrolytic enzymes to degrade polymers into monomeric subunits |
Cocci bacteria | spherical-cell bacteria |
Bacillus | rod-shaped-cell bacteria |
Sprilla | rigidly-twisted-cell bacteria |
Spirochete | flexible-twisted-cell bacteria |
Inclusion bodies | aggregates of organic molecules that facilitate in the prokaryotic cell’s functions (akin to organelles) |
Glycolayx | bacterial capsule, a polysaccharide layer |
Capsid | virus with protein shell without nucleic acid inside |
Nucleocapsid | virus with protein shell with nucleic acid inside |
Viral matrix proteins | proteins that attach the membrane to the enveloped virus |
Hershey and Chase experiment | infected E.coli with radiolabelled phosphorus and sulfur. |
Anfinsen experiment | experiment involving denaturing a ribonuclease with beta-mercapoethanol and 8M, which cleaves disulfide bonds. Enzymatic activity restore after refold. Structure fluctuates but stabilized by other structures. |