Question

69. Which of the following cannot take part in gluconeogenesis?

a) lactate

b) fatty acids

c) alanine

d) glycerol

71. Which hormone is least likely to increase in the blood during exercise?

a) insulin

b) cortisol

c) glucagon

d) epinephrine

72. Which of the following is not considered a gluconeogenic hormone?

a) cortisol

b) insulin

c) glucagon

d) epinephrine

Answer 1

69. Answer is option 'b'- fatty acids.

Gluconeogenesis is the process of production of glucose by the liver from any carbon source which are non-carbohydrates. These sources are usually the products formed by breakdown of proteins, lipids etc. Liver uses glucogenic amino acids (like alanine) but not ketogenic amino acids (like lysine and leucine) because, ketogenic amino acids cannot generate glucose, instead they form ketone bodies. Liver uses substrates like lactate and pyruvate for gluconeogenesis. Liver also uses glycerol, but not fatty acids because, fatty acids cannot generate glucose, instead they give rise to acetyl CoA which in turn gets converted into carbon dioxide.

71.Answer is option-'a' - insulin.

72.Answer is option -'b'- insulin.

Explanation for '71' and '72'.

Insulin is a hormone that facilitates the uptake or absorption of glucose by cells.The absorbed glucose is then converted into glycogen or fats.

During exercise or any high intensity activity, the body keeps utilising glucose to produce energy. This reduces the glucose levels in the blood. Extremely low levels of glucose results in a condition called 'hypoglycemia'. In order to prevent hypoglycemic condition, gluconeogenic hormones called epinephrine, cortisol and glucagon are secreted. Epinephrine and glucagon promote breakdown of glycogen (glycogenolysis) and stimulate the production of glucose (gluconeogenesis). Cortisol promotes breakdown of proteins and lipids for gluconeogenesis.The secretion of insulin reduces under hypoglycemic condition in order to prevent further breakdown of glucose.