Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cell Biology and Genetics > Regulation of Protein Function > Flashcards

Regulation of Protein Function Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Name 3 ways protein function can be regulated in the short term

A
  • Substrate and product concentration
  • Allosteric regulation
  • Covalent modification
  • Proteolytic cleavage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In which two ways can protein function can be regulated in the long term?

A
  • Change in rate of protein synthesis

- Change in rate of protein degradation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name the 3 ways protein function is regulated by substrate and product concentration

A
  • Isoenzymes (different forms of same enzyme)
  • Limited availability of co-enzymes
  • Product inhibition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name 3 characteristics of allosteric enzymes

A
  • Sigmoid relationship between rate and substrate concentration
  • Multisubunit
  • 2 conformations - T State (low affinity) and R State (high affinity)
  • Substrate binding makes subsequent binding easier
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an allosteric activator?

A
  • A molecule which increases the proportion of enzyme in R state
  • More hyperbolic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is an allosteric inhibitor?

A

Increases proportion of enzyme in the T State

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which enzyme involved in glycolysis is allosterically regulated?

A

Phosphofructokinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name an allosteric activator and inhibitor of phosphofructokinase

A

Activator - AMP, fructose-2,6-bisphosphate

Inhibitor - ATP, Citrate, H+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which process is an example of covalent modification associated with protein regulation?

A

Phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which enzymes activate and reverse phosphorylation?

A

Activate - Kinases

Reverse - Protein Phosphotases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name 3 characteristics or effects of using phosphorylation in protein function regulation

A
  • Adds 2 negative charges
  • Phosphoryl group can make H bonds
  • Rate can be adjusted (phosphorylation/dephosphorylation)
  • Links cell energy status to metabolism through ATP
  • Allows for amplification
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How can the regulation of glycogen synthesis and breakdown be described?

A

Reciprocal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which 2 enzymes regulate glycogen synthesis and breakdown?

A
  • Phosphorylase Kinase

- Glycogen Synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is specific proteolytic cleavage?

A

Common way that inactive enzymes are activated in biological systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Give 3 examples of specific proteolytic cleavage mechanisms

A
  • Digestive enzymes
  • Protein hormones
  • Blood clotting
  • Developmetal processes
  • Apoptosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Is specific proteolytic cleavage reversible?

A

No

17
Q

What controls pancreatic protease activation?

A

Trypsin

18
Q

What regulates specific proteolytic cleavage and how?

A
  • Endogenous inhibitors

- Irreversibly bind to enzyme

19
Q

What is a zymogen?

A

The inactive form of an enzyme

20
Q

What are the main 3 steps in the blood clotting cascade?

A
  1. Factor X activation
  2. Thrombin activation
  3. Formation of fibrin clot
21
Q

What is the inactive form of thrombin?

A

Prothrombin

22
Q

What is the location of thrombin on the protein?

A

C-terminal

23
Q

Which domain keeps prothrombin in the inactive form?

A

Kringle domains

24
Q

What do GLA domains do in relation to thrombin?

A

Target thrombin to appropriate sites for activation

25
Q

What post-translationally modifies clotting factors?

A

GLA domains

26
Q

Name 3 characteristics of fibrinogen

A
  • Fibrous protein
  • Pre-cursor of fibrin
  • 3 globular domains linked by rods
  • Negatively charged N-terminals
27
Q

How does fibrinogen structure prevent fibrinogen aggregation?

A

Negative charge on alpha and beta chains on N-terminal

28
Q

Which enzyme cleaves negatively charged fibrinopeptides?

A

Thrombin

29
Q

How do the N and C terminals of fibrin interact?

A

Globular domains on C terminals interact with N terminal ends

30
Q

How is a fibrin clot stabilised?

A

Amide bonds between lysine and glutamate residues

31
Q

Which enzyme catalyses fibrin clot cross-linking?

A

Transglutaminase

32
Q

What is haemophilia caused by?

A
  • Factor VIII defect

- Limited proteolysis by thrombin

33
Q

What function does thrombin have in the clotting cascade?

A
  • Allosteric feedback regulator

- Forms self-sustaining pathway

34
Q

What 4 mechanisms can help stop the clotting process?

A

Thrombin Localisation - dilution by blood/removal by liver
Digestion by Proteases
Specific Inhibitors
Fibrinolysis - Plasmin breaks down fibrin into fibrin filaments

Cell Biology and Genetics (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions