Correct Option
The correct matching is A-2, B-3, C-1, D-5.
- Ptyalin (A) is an enzyme, also known as salivary amylase, found in saliva. Its primary physiological role is to digest starch into maltose and dextrin.
- Pepsin (B) is a proteolytic enzyme secreted by the gastric glands in the stomach. It functions in an acidic environment to digest proteins into smaller peptides.
- Renin (C) is an enzyme secreted by the juxtaglomerular cells of the kidneys. It converts angiotensinogen in the blood into angiotensin I, initiating the renin-angiotensin-aldosterone system (RAAS) which regulates blood pressure.
- Oxytocin (D) is a hormone produced by the hypothalamus and released by the posterior pituitary gland. It induces the contraction of smooth muscles, particularly in the uterus during childbirth and in the mammary glands for milk ejection.
Incorrect Options
- Option (2) (3425): This option incorrectly matches Pepsin (B) with 'hydrolyses fats' (4) and Renin (C) with 'digests starch' (2). Pepsin digests proteins, and Renin converts angiotensinogen.
- Option (3) (2351): This option incorrectly matches Renin (C) with 'induces contraction of smooth muscles' (5) and Oxytocin (D) with 'converts angiotensinogen in blood into angiotensin' (1). Renin's role is in the RAAS, and Oxytocin induces smooth muscle contraction.
- Option (4) (3124): This option incorrectly matches Ptyalin (A) with 'digests proteins' (3), Renin (C) with 'digests starch' (2), and Oxytocin (D) with 'hydrolyses fats' (4). Ptyalin digests starch, Renin is involved in RAAS, and Oxytocin induces smooth muscle contraction.