Macromolecules Flashcards
a) Feature of collagen
b) What side chains do amino acids in the membrane have
c) How can the affinity of a ligand binding be altered
d) Why does C-N bond in protein secondary structure have partial double bond characteristics
e) What enzymes are mainly associated with allostery
a) High frequency of proline in collagen’s sequence prevents α-helix formation
b) Non-polar side chains
c) The binding of one ligand can alter the affinity of ligand binding at another site
d) Electrons from the nitrogen atom of the peptide bond delocalise to the C-N bond, giving it partial double bond characteristics
e) Multi-subunit enzymes
a) What condition is necessary for a spontaneous chemical reaction
b) How are a-helices stabilized
c) What causes sickle cell anaemia
d) What amino acid side chains are found in the core of cytosolic proteins
e) How does oxygen bind to haemoglobin
a) A decrease in Gibbs free energy (negative ΔG)
b) Stabilized by hydrogen bonds between residue i and residue i + 4
c) Caused by the replacement of a glutamate residue with a valine in the β-subunit
d) Hydrophobic
e) Binding is cooperative and shows sigmoidal binding properties
a) Mechanism of serine proteases
b) How do allosteric activators and inhibitors alter the activity of an enzyme
c) What is ΔGº equal to
d) What are α helices associated with
e) How do enzymes catalyse a chemical reaction
a) Use a reactive serine residue to perform nucleophilic attack on the substrate molcule
b) By changing the shape of the active site
c) -RTlnKeq
d) Characteristic dihedral angles
e) Stabilise the transition state
a) What sort of regulation is allosteric control
b) What does feedback inhibition prevent
c) What is partly controlled by expression of the enzyme
d) What amino acid isn’t found in proteins
e) What amino acid is acetylated in histones
a) A rapid regulation of pathways usually from intracellular cues
b) Prevents accumulation of the products of a given pathway
c) Long-term regulation of flux through a pathway
d) Ornithine
e) Lysine
a) What is an important covalent modification that regulates activity in many enzymes
b) What amino acid can be transaminated to form oxaloacetate
c) What covalent bond is formed between cysteine side chains
d) What is an example of super-secondary structure
e) What is a molecule that decreases enzyme activity by increasing KM without changing Vmax
a) Phosphorylation
b) Aspartate
c) Disulfide bond
d) βαβ motif
e) Competitive inhibitor
a) What contains two essential Asp residues in the active site
b) What is inhibited by penicillin in suicide inhibition
c) What uses a catalytic zinc ion for transition state stabilisation
a) HIV protease
b) Glycopeptide transpeptidase
c) Carbonic anhydrase
