Discussion
Home ‣ Biochemistry ‣ Cell Signalling and Transduction Comments
- Question
In paracrine signaling, the signaling molecules affects only
Options- A. target cells close to the cell from which it was secreted
- B. target cells distant from its site of synthesis in cells of an endocrine organ
- C. both (a) and (b)
- D. none of the above
- Correct Answer
- target cells close to the cell from which it was secreted
- 1. Which of the following statement is incorrect?
Options- A. The principal lipophilic hormones that binds to receptors located in the plasma membranes are prostaglandins
- B. Prostaglandins are synthesized from arachidonic acid
- C. Prostaglandins act as paracrine signaling molecules
- D. None of the above Discuss
- 2. The enzyme that catalyzes the splitting of PIP2 into two molecules of inositol triphosphate (IP3) and diacylglycerol in cell signaling, is
Options- A. phosphokinase C
- B. phospholipase C
- C. phosphodiesterase C
- D. lipokinase Discuss
- 3. The binding of ligands to many G-proteins linked receptors leads to shortlived
Options- A. increase in the concentration of certain intracellular signaling molecules called second messenger
- B. decrease in the concentration of certain intracellular signaling molecules called second messenger
- C. increase in the concentration of certain extracellular signaling molecules called first messenger
- D. decrease in the concentration of certain extracellular signaling molecules called first messenger Discuss
- 4. Simple nerve reflexes use signaling molecules called
Options- A. neurotransmitters
- B. nitric oxides
- C. G proteins
- D. proteases Discuss
- 5. The major second messengers are
Options- A. cAMP
- B. cGMP
- C. DAG
- D. All of these Discuss
- 6. A signal cascade induced by adrenaline or thyroxine
Options- A. must begin with receipt of the signal molecule by a surface receptor
- B. involves the activation of a G protein
- C. results in the activation of a sequence of enzymes needed for the cell effect
- D. all of the above Discuss
- 7. Self-phosphorylation is an excellent mechanism for triggering specific catalytic function of the proteins involved in signal cascades because it
Options- A. changes the shape and thus the enzymatic activity of the proteins involved
- B. makes the receptor more likely to capture the signaling, molecule
- C. allows hydrophilic signaling molecules to cross the plasma membrane
- D. None of the above Discuss
- 8. Which of the following is not a type of signaling molecule?
Options- A. Testosterone
- B. Insulin
- C. Thyroxin
- D. Adenylate cyclase Discuss
- 9. When a __________ reaches its __________ , there is a specific means of receiving it and acting on the message. This task is the responsibility of specialized proteins called __________ .
Options- A. signaling molecule; receptor; G proteins
- B. signaling molecule; target cell; G proteins
- C. signaling molecule; target cell; receptors
- D. kinase; receptor; proteases Discuss
- 10. Nitroglycerin has long been administered to human patients suffering from chronic chest pain (angina). This medication works because it
Options- A. mimics the action of signal receptors
- B. is broken down into hormones that affect the heart
- C. interferes with chemical cascades that trigger contraction of heart muscle
- D. breaks down into nitric oxide, which increases blood flow to the heart Discuss
Cell Signalling and Transduction problems
Search Results
Correct Answer: None of the above
Correct Answer: phospholipase C
Correct Answer: increase in the concentration of certain intracellular signaling molecules called second messenger
Correct Answer: neurotransmitters
Correct Answer: All of these
Correct Answer: all of the above
Correct Answer: changes the shape and thus the enzymatic activity of the proteins involved
Correct Answer: Adenylate cyclase
Correct Answer: signaling molecule; target cell; receptors
Correct Answer: breaks down into nitric oxide, which increases blood flow to the heart
Comments
There are no comments.More in Biochemistry:
Programming
Copyright ©CuriousTab. All rights reserved.