Proteolysis

Question 1

What is proteolysis?

Answer 1

Proteolysis is the biochemical process of breaking down proteins into smaller peptides or amino acids.

Question 2

True or False: Proteolysis is essential for protein turnover in cells.

Answer 2

True

Question 3

Fill in the blank: Proteolysis is primarily carried out by enzymes known as ______.

Answer 3

proteases

Question 4

What are the two main types of proteolysis?

Answer 4

Endopeptidase and Exopeptidase.

Question 5

Multiple Choice: Which of the following is NOT a type of protease? A) Serine protease B) Cysteine protease C) Lipase D) Aspartic protease

Answer 5

C) Lipase

Question 6

What role does proteolysis play in digestion?

Answer 6

It breaks down dietary proteins into amino acids for absorption.

Question 7

True or False: Proteolysis can occur both intracellularly and extracellularly.

Answer 7

True

Question 8

Fill in the blank: The process of proteolysis is crucial for ______ regulation.

Answer 8

cellular

Question 9

What is the function of proteasomes in proteolysis?

Answer 9

Proteasomes degrade ubiquitinated proteins within the cell.

Question 10

Multiple Choice: Which enzyme class is primarily responsible for cleaving peptide bonds? A) Lipases B) Glycosidases C) Proteases D) Nucleases

Answer 10

C) Proteases

Question 11

What is the significance of zymogens in proteolysis?

Answer 11

Zymogens are inactive precursors that require activation to become active proteases.

Question 12

True or False: Proteolysis can lead to the activation of signaling pathways.

Answer 12

True

Question 13

Fill in the blank: The amino acids released by proteolysis can be used for ______ synthesis.

Answer 13

protein

Question 14

Multiple Choice: Which of the following conditions can stimulate proteolysis? A) Starvation B) Overeating C) Sleep D) None of the above

Answer 14

A) Starvation

Question 15

What is the role of lysosomes in proteolysis?

Answer 15

Lysosomes contain proteases that degrade proteins within the cell.

Question 16

True or False: Proteolysis is only important for protein breakdown.

Answer 16

False

Question 17

Fill in the blank: Proteolysis is involved in the regulation of ______ and metabolic pathways.

Answer 17

cell cycle

Question 18

What is the relationship between proteolysis and cancer?

Answer 18

Dysregulation of proteolysis can contribute to cancer progression and metastasis.

Question 19

Multiple Choice: Which of the following diseases is associated with abnormal proteolysis? A) Alzheimer’s B) Diabetes C) Hypertension D) All of the above

Answer 19

A) Alzheimer’s

Question 20

What is the role of caspases in proteolysis?

Answer 20

Caspases are proteases that play essential roles in programmed cell death (apoptosis).

Question 21

True or False: Proteolysis can only occur in the presence of water.

Answer 21

True

Question 22

Fill in the blank: The degradation of misfolded proteins is a critical function of ______.

Answer 22

proteolysis

Question 23

What is the effect of proteolysis on cellular signaling?

Answer 23

Proteolysis can activate or deactivate signaling molecules, influencing cellular responses.

Question 24

Multiple Choice: Which type of protease is involved in blood clotting? A) Serine protease B) Metalloprotease C) Cysteine protease D) Aspartic protease

Answer 24

A) Serine protease

Question 25

What are the different classifications of proteases?

Answer 25

1) proteases 2) proteinases 3) peptidase 4) cathepsins

Question 26

What are endopeptidases and exopeptidases?

Answer 26

Endopeptidases- enzymes that break peptide bonds within a protein chain----> beginning of a chain Exopeptidases- enzymes that break peptide bonds at the terminal end of a chain

Question 27

What are aminopeptidases and carboxypeptidases

Answer 27

Aminopeptidases- enzymes that cleave amino acids from N-Terminal of proteins Carboxypeptidases- enzymes that break down proteins by splitting off amino acids

Question 28

What is protein activation and protein degradation?

Answer 28

Protein activation- structural/conformational chances to enhance proteins biological activity. Protein degradation- proteins are broken down into amino acids.

Question 29

What is protein activation and protein degradation?

Answer 29

Protein activation- structural/conformational chances to enhance proteins biological activity. Protein degradation- proteins are broken down into amino acids.

Question 30

Explain protein activation by proteolysis?

Answer 30

This involves the cleavage of specific peptide bonds within a protein---> this leads to structural changes within the protein. 1) Zymogen activation: -zymogens are enzymes/signalling proteins that are synthesised or inactive precursors. 2) Confirmation changes: -cleavage allows the protein to adopt an active site, exposing/creating the active site. 3) Regulatory role: -proteolytic activation serves as a regulatory mechanism this controlling metabolic and physiological processes.

Question 31

What is ubiquitylation?

Answer 31

Ubiquitylation- involves the attachment of ubiquity (small protein) to a target protein.

Question 32

Explain the components of the ubiquitinating enzyme complex

Answer 32

Ubiquitin activation enzyme (E1): -formation of thioester bond between the C-terminus of ubiquitin and a cystein on E1 Ubiquitin-conjugating enzyme (E2): -transfer of ubiquitin to a cystein on E2 Ubiquitin-protein ligase (E3): -transfer of ubiquitin (small protein) from E2 to a lysine on a target protein.

Question 33

Explain the components of the ubiquitinating enzyme complex

Answer 33

Ubiquitin activation enzyme (E1): -formation of thioester bond between the C-terminus of ubiquitin and a cystein on E1 Ubiquitin-conjugating enzyme (E2): -transfer of ubiquitin to a cystein on E2 Ubiquitin-protein ligase (E3): -transfer of ubiquitin (small protein) from E2 to a lysine on a target protein.

Question 34

Explain the N-End rule

Answer 34

This explains the relationship between protein half life and amino terminal amino acid residue. N-terminal residues are associated with rapid degradation. N terminal residues are also tagged for degradation by the ubiquitin-proteasome system

Question 35

Explain the N-End rule

Answer 35

This explains the relationship between protein half life and amino terminal amino acid residue. N-terminal residues are associated with rapid degradation. N terminal residues are also tagged for degradation by the ubiquitin-proteasome system

Question 36

What class of proteases is involved in the coagulation cascade?

Answer 36

Carboxyproteases.

Question 37

What is the role of factor IX proprotein?

Answer 37

Zymogen of the clotting cascade

Question 38

How many proteolytic cleavages are required to convert preproinsulin to mature insulin?

Answer 38

2