Question

Which reaction is typically catabolic?

A. A --> B + C + Energy

B. A + B + Energy --> C

Which statement about intracellular receptors is NOT true?

A. binding of intracellular receptors can be accomplished by peptide hormones

B. binding of intracellular receptors typically triggers DNA transcription

C. amino-acid derived hormones can bind intracellular receptors

D. hormone classes that bind intracellular receptors can sometimes bind membrane receptors

Which is TRUE of catecholamines?

A. catecholamines are derived from tyrosine

B. catecholamines behave like steroid hormones

C. catecholamines bind intracellular receptors

Answer 1

ANSWER :

1. The reaction 'A' is typically a catabolic reaction, because a specific amount of energy (or heat) emerged out with the formation of products. Example :- cellular respiration.

2. The amino acid derived and peptide hormones are hydrophilic in nature, hence to initiate the further signalling pathway, they have to generate secondary messenger and bind to the intracellular receptors in their target cells. Hence option (B) is the correct answer choice.

3. All the catecholamines or hormones(e.g.- epinephrine, nor-epinephrine, and dopamine) adrenal medulla are derived from the tyrosine amino acid precursor. Hence option (A) is the correct answer choice.