Biochemistry
Regulation Of Enzyme Activity
Compiled By Simon Mwangi
Edition: 2024/25
, Science | Biochemistry I of VI pages
1. 5 says of regulating enzymatic activity
Allosteric controlMultiple forms of enzymes Reversible covalent modification Proteolytic activation
2. Example of reversible covalent modification
Phosphorylation
3. What does allosteric regulation do?
Modulates activity of key enzymes through reversible binding ina different site than active site
4. Is allosteric regulation fast or slow working?
Fast
5. What are allosteric effectors typically?
Small chemicals either positive or negative
6. Example of allosteric enzyme
Aspartate transcarbamoylase (ATCase)
7. What does Aspartate transcarbamoylase (ATCase) catalyse?
First reaction of pyrimidine synythessi
8. What is the committed step?
The step which is determines what reactive pathway youll take, after that step (typically the first step) there
9. What is feedback inhibition
When the last product inhibits the first step so the reaction cant happen againLike negative feedback
10. Is cytidine a pyrimidine or purine?
Pyrimidine
11. What kind of kinetics does ATCase display?
Sigmoidal kinetics
12. How many subunits does native ATCase consist of?
12:6 regulatory (3 dimers)6 catalytic (2 trimers)
13. What is an analog?
Something that is structurally and chemically similar
14. What does PALA do?
Freeze it in the R state (suicide inhibitor)
15. Is ATP a positive or negative regulator?
Postive (favours R-state)
16. Is ATP a positive or negative regulator?
Negative (favours T-state)
Biochemistry 2024/25 Edition
Regulation Of Enzyme Activity
Compiled By Simon Mwangi
Edition: 2024/25
, Science | Biochemistry I of VI pages
1. 5 says of regulating enzymatic activity
Allosteric controlMultiple forms of enzymes Reversible covalent modification Proteolytic activation
2. Example of reversible covalent modification
Phosphorylation
3. What does allosteric regulation do?
Modulates activity of key enzymes through reversible binding ina different site than active site
4. Is allosteric regulation fast or slow working?
Fast
5. What are allosteric effectors typically?
Small chemicals either positive or negative
6. Example of allosteric enzyme
Aspartate transcarbamoylase (ATCase)
7. What does Aspartate transcarbamoylase (ATCase) catalyse?
First reaction of pyrimidine synythessi
8. What is the committed step?
The step which is determines what reactive pathway youll take, after that step (typically the first step) there
9. What is feedback inhibition
When the last product inhibits the first step so the reaction cant happen againLike negative feedback
10. Is cytidine a pyrimidine or purine?
Pyrimidine
11. What kind of kinetics does ATCase display?
Sigmoidal kinetics
12. How many subunits does native ATCase consist of?
12:6 regulatory (3 dimers)6 catalytic (2 trimers)
13. What is an analog?
Something that is structurally and chemically similar
14. What does PALA do?
Freeze it in the R state (suicide inhibitor)
15. Is ATP a positive or negative regulator?
Postive (favours R-state)
16. Is ATP a positive or negative regulator?
Negative (favours T-state)
Biochemistry 2024/25 Edition
