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Q1)Which of the following is/are likely to elicit a slow, but long-lasting or ev

ID: 166098 • Letter: Q

Question

Q1)Which of the following is/are likely to elicit a slow, but long-lasting or even permanent cellular response?

An odorant that binds to a G protein-coupled receptor

A growth factor that binds to a receptor tyrosine kinase

A steroid hormone

Both growth factor signaling and steroid hormone signaling

Q2)ras, like many small G-proteins, hydrolyzes GTP somewhat slowly on its own, but the GTPase activity is increased significantly in the presence of GTPase activating proteins (GAPs). Imagine you discovered a novel mutation in a ras GTPase activating protein (a “ras GAP”) that binds to ras less efficiently than normal ras GAP. This mutation would have the effect of:

Increasing cAMP production

Increasing Protein Kinase A activity

Increasing glucose production

Increasing cell proliferation.

All of the above

None of the above

Q3)Which of the following statements is TRUE?

The entropy of a closed system never increases.

The sign (+ or -) of the change in enthalpy tells you whether a reaction is favorable or unfavorable.

G must be < 0.

If the free energy of the products (Gproducts) is greater than that of the reactants (Greactants) the reaction is favorable.

Both the 2nd and 3rd answers above

An odorant that binds to a G protein-coupled receptor

A growth factor that binds to a receptor tyrosine kinase

A steroid hormone

Both growth factor signaling and steroid hormone signaling

Q2)ras, like many small G-proteins, hydrolyzes GTP somewhat slowly on its own, but the GTPase activity is increased significantly in the presence of GTPase activating proteins (GAPs). Imagine you discovered a novel mutation in a ras GTPase activating protein (a “ras GAP”) that binds to ras less efficiently than normal ras GAP. This mutation would have the effect of:

Increasing cAMP production

Increasing Protein Kinase A activity

Increasing glucose production

Increasing cell proliferation.

All of the above

None of the above

Q3)Which of the following statements is TRUE?

The entropy of a closed system never increases.

The sign (+ or -) of the change in enthalpy tells you whether a reaction is favorable or unfavorable.

G must be < 0.

If the free energy of the products (Gproducts) is greater than that of the reactants (Greactants) the reaction is favorable.

Both the 2nd and 3rd answers above

Explanation / Answer

Answer (1) Hormones are slow acting chemical messengers whose actions lasts long.

Answer (2) ras is involved in apoptosis, mutation would results in increased cell proliferation.

Answer (3) both 2nd and third answers are correct. for a reaction to be spontaneous G must be less than zero or negative. the change in sign of delta H always tells about the favourability of reaction. if delta H is negative the reaction is spontaneous.