1. Protein kinase C is mainly activated by which combination of signals?
A.
Diacylglycerol and calcium ions
B.
Cyclic AMP and sodium ions
C.
Nitric oxide and chloride ions
D.
ATP and glucose
Correct Answer:
Diacylglycerol and calcium ions
Explanation:
Many protein kinase C forms are activated when diacylglycerol and calcium ions act together.
2. Which lipid second messenger directly helps activate protein kinase C?
A.
Diacylglycerol
B.
Cholesterol
C.
Triglyceride
D.
Bile salt
Correct Answer:
Diacylglycerol
Explanation:
Diacylglycerol, or DAG, is a lipid second messenger that activates protein kinase C.
3. What type of enzyme is protein kinase C?
A.
A protein-phosphorylating enzyme
B.
A DNA-cutting enzyme
C.
A carbohydrate-digesting enzyme
D.
A lipid-storing enzyme
Correct Answer:
A protein-phosphorylating enzyme
Explanation:
Protein kinase C transfers phosphate groups from ATP to specific target proteins.
4. What is a major effect of protein kinase C activation inside a cell?
A.
Phosphorylation of target proteins
B.
Destruction of all cellular DNA
C.
Conversion of proteins into carbohydrates
D.
Removal of all calcium ions from the body
Correct Answer:
Phosphorylation of target proteins
Explanation:
Activated protein kinase C changes cell activity by phosphorylating specific proteins.
5. Where does activated protein kinase C commonly move before acting on membrane-associated targets?
A.
To the cell membrane
B.
To the extracellular fluid
C.
To the cell wall
D.
To the digestive tract
Correct Answer:
To the cell membrane
Explanation:
Activation commonly causes protein kinase C to move toward the cell membrane, where DAG is present.
6. Which ion commonly participates in the activation of conventional protein kinase C?
A.
Calcium ion
B.
Iron ion
C.
Fluoride ion
D.
Iodide ion
Correct Answer:
Calcium ion
Explanation:
Calcium ions help activate conventional forms of protein kinase C along with diacylglycerol.
7. Protein kinase C belongs to which broad group of signaling proteins?
A.
Protein kinases
B.
Structural carbohydrates
C.
Antibodies
D.
Membrane lipids
Correct Answer:
Protein kinases
Explanation:
Protein kinase C is a protein kinase because it adds phosphate groups to proteins during cell signaling.
8. Which molecule is produced from membrane phospholipid signaling and helps activate protein kinase C?
A.
Diacylglycerol
B.
Hemoglobin
C.
Glycogen
D.
Urea
Correct Answer:
Diacylglycerol
Explanation:
Diacylglycerol is generated during phospholipid signaling and serves as an important activator of protein kinase C.
9. What happens to protein kinase C when it is activated?
A.
Its kinase activity increases
B.
It permanently becomes DNA
C.
It stops interacting with proteins
D.
It changes into a carbohydrate
Correct Answer:
Its kinase activity increases
Explanation:
Activation increases protein kinase C activity, allowing it to phosphorylate downstream target proteins.
10. Why is protein kinase C important in hormone and cell signaling?
A.
It relays signals by modifying target proteins
B.
It carries oxygen through the blood
C.
It forms the cell wall
D.
It digests food in the intestine
Correct Answer:
It relays signals by modifying target proteins
Explanation:
Protein kinase C helps transmit cellular signals by phosphorylating proteins that control cell responses.
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