Consider the following statements about enzymes: 1. Enzyme activity is affected by pH. 2. All enzymes have an optimum temperature around 37°C. 3. Enzymes are reusable. Which of the above is/are correct? MCQ with Answer and Explanation

Explanation:
Insulin-like Growth Factor 1 (IGF-1), also known as somatomedin C, is a peptide hormone structurally similar to insulin. It is primarily synthesized and secreted by the liver (and to a lesser extent by other tissues) in response to stimulation by Growth Hormone (GH). IGF-1 mediates most of the growth-promoting (anabolic) effects of GH. It stimulates the proliferation and differentiation of chondrocytes (cartilage cells) in the epiphyseal plates of bones, promotes protein synthesis in muscles, and supports the growth of various other tissues.

Explanation:
Salivary amylase (ptyalin) hydrolyzes starch into maltose and dextrins in the mouth. It functions optimally at neutral to slightly alkaline pH. Pepsin digests proteins in the stomach, lipase digests fats, trypsin is a pancreatic protease. Salivary amylase action ceases in the acidic stomach.

Explanation:
Acetobacter aceti and related species oxidize ethanol to acetic acid (vinegar) in the presence of oxygen. This is an aerobic fermentation process. Lactobacillus produces lactic acid, Pseudomonas can spoil food, Bacillus includes various industrial strains. Vinegar is used as a condiment and preservative.