Question

During Diabetic Ketosis when insulin is absent, fats are released and processed by Beta-oxidation. Which of the following statements are TRUE:

i) Acetyl-CoA reacts with oxaloacetate to create alpha-ketoglutarate and processed by the TCA cycle;
ii) in the absence of insulin there is a depletion of oxaloacetate and accumulation of Acetyl-CoA;
iii) Acetyl-CoA can feed into the formation ketone bodies and excess ketone body production can lower blood pH in diabetics.

Answer 1

Question

Option A:-Incorrect

Reason:- The first step of citric acid involves a combination of acetyl CoA with 4 carbon molecule oxaloacetate to yield citrate a 6 carbon molecule.

Alpha-ketoglutarate is formed in the 4th step of the citric acid cycle by oxidative decarboxylation of isocitrate into alpha-ketoglutarate that is a 5 carbon molecule. The reaction is catalyzed by isocitrate dehydrogenase enzyme.

Option B:- True

Reason:-Low insulin in the bloodstream stimulates the synthesis of fatty acid from adipose tissue. This increases the oxidation of fatty acid into acetyl CoA. This leads to the accumulation of acetyl CoA because of the low availability of oxaloacetate (a citric acid intermediate and combines with acetyl Co A to yield citrate). The depletion in oxaloacetate leads to the accumulation of acetyl CoA and triggers ketogenesis.

Option C:- True

Reason:-Ketone bodies are produced by the liver under fasting, starvation, and low blood glucose level. These are an alternative source of energy for our body when the level of glucose is low in the body. Diabetic type 1 involves the production of ketone bodies and excess of ketone bodies in lowers the blood ph level in a diabetic patient This triggers the kidney to release acidic urine.