Question

Which of the following statements is most correct regarding the intracellular chemical signals known as "second messengers"? Select one: a. Second messengers usually act to remove nitric oxide (NO) from the cell. b. Cyclic AMP and calcium may be second messengers. c. Second messengers usually inactivate protein kinase enzymes. d. Second messengers act through receptors called K-proteins.

Answer 1

Answer:

Cyclic AMP and calcium may be second messengers.

Explanation:

these are signalling molecules that are located inside the cells,They are releases  when cells   are in contact with  signals from an extracellular molecule. the extracellular molecules that cause the chemical  reaction  in an external environment  in the second messenger are called first messenger.

the basic mechanisms of second messenger involve the binding of ligands to the cell membrane receptors( usually a trans membrane protein).causing   conformational  change in the receptor protein. The latter change affect the structural and functional activities of the receptors protein with a consequent  production of second messenger,

Response of the cells  to the first messenger my cause different form of cellular reactions; the cells may  undergo depolarization  with influx of out flux of ions, differentiate to specialized cells  or migrate to another location.

Examples of first messenger are hormones and neurotransmitters, while calcium ions, cyclic GMP,AMP, diaclyglycerol are examples of first messengers.

Most first messengers are peptide hormones.Some may be streroid, However, the hydrophilic nature of the peptide hormone restrict their movement, at the cell membranes. Therefore most first messengers made of  peptide  are first converted to second messenger to  bring about their signalling effects.The usually mark the beginning of cascade events by second messengers.

Second messengers are usually classified based on their polarity and molecular form this include the

hydrophobic molecules ;diacyglecerol,phosphatdylinotisols. These diffuse  through the membrane  into intramembrane space of cells cause signalling effects in the cell.

the hydrophiliic  molecules  are  located in the cystol  of cells. Example are  Cylic AMP. GMP, Calcium,

N02, CO,H2S are polar molecules that easily diffuse into the cells to cause signalling effects, they are the third Classification of second messengers.

Answer 2

Answer: Option B.

Cyclic AMP and calcium may be second messengers.

Explanation:

Second messengers are intracellular chemical molecule which is released by the cell when the extracellular signal molecule is exposed, it relay signals that it received from the receptors present on cell surface. Examples of Second messengers molecule include cyclic AMP, cyclic GMP, calcium, inositol triphosphate and diacyclglycerol.

Cyclic Amp is responsible for ntracellular signal transduction and it regulate T cell during transcription.