L12 Protein Function Enzymology Flashcards
What do enzymes do?
Enzymes catalyze reactions by lowering activation energy.
What is the induced fit model?
An enzyme changes shape upon substrate binding to improve catalysis.
How do enzymes increase reaction speed?
They lower the activation energy and can catalyze hundreds of reactions per second.
Give an example of enzyme specificity.
Sucrase only hydrolyzes sucrose, not other disaccharides.
Name two industrial applications of enzymes.
Biological detergents (proteases, lipases) and high-fructose corn syrup production (glucose isomerase).
What part of an antigen does an antibody recognize?
The epitope.
Describe the structure of an antibody.
Two heavy and two light chains connected by disulfide bonds, with variable and constant regions.
What determines antigen specificity in antibodies?
The variable region.
How does hemoglobin regulate oxygen binding?
pH and BPG levels influence oxygen affinity.
What is the Bohr effect?
Lower pH enhances oxygen release from hemoglobin.
What is the difference between hemoglobin’s T and R states?
T-state has low O₂ affinity, R-state has high O₂ affinity.
What are the main functions of membrane proteins?
Cell recognition, signal transduction, and transport.
What is unique about the structure of membrane proteins?
Hydrophobic regions interact with membranes, hydrophilic regions face the aqueous environment.
Name a key function of hormone receptors in membranes.
They mediate signal transduction (e.g., beta-blockers target these receptors).
What is the basic repeating unit of collagen?
Gly-X-Y, where X is proline and Y is hydroxyproline.
Why is vitamin C important for collagen?
It is required for hydroxyproline formation; deficiency leads to scurvy.
What is the function of actin and myosin?
Actin forms filaments, and myosin enables muscle contraction.
What are amyloid fibrils?
Insoluble protein aggregates that cause diseases like Alzheimer’s.
How do amyloid fibrils cause damage?
They accumulate and disrupt tissue function
