The vitamin that is a coenzyme in the metabolism of carbohydrates and branched-chain amino acids is: MCQ with Answer and Explanation

Explanation:
Oxytocin is a peptide hormone produced by the paraventricular nucleus of the hypothalamus and released by the posterior pituitary. In females, it has two major roles: 1) During childbirth, it stimulates powerful contractions of the uterine smooth muscle, facilitating labor and delivery (this is a positive feedback loop). 2) During lactation, it stimulates the contraction of myoepithelial cells surrounding the alveoli in the mammary glands, causing the ejection (let-down) of milk into the ducts in response to suckling. It does not produce milk; prolactin does that.

Explanation:
Eukaryotic ribosomes are 80S and composed of a small 40S subunit and a large 60S subunit. Prokaryotic ribosomes are 70S with 30S and 50S subunits. The S (Svedberg) value is a measure of sedimentation rate, not simply additive. Both ribosome types synthesize proteins, but the structural difference allows selective antibiotic targeting (e.g., streptomycin acts on 70S).

Explanation:
In RNA, uracil replaces thymine and pairs with adenine (A-U). In DNA, adenine pairs with thymine. Guanine always pairs with cytosine.