Biochem

Question 1

Primary carnitine deficiency

Answer 1

Carnitine def impairs fatty acid transport from the cytoplasm into the mitochondria, preventing B-oxidation of fatty acids into acetyl-CoA. Leads to cardiac and skeletal myocyte injury (lack of ATP from citric acid cycle) and impaired ketone production by liver during fasting periods

Question 2

Pellagra

Answer 2

Niacin (B3) def that presents w diarrhea, dementia and dermatitis. Niacin is a precursor for NAD and NADP, 2 important co factors for many dehydrogenase and reductase enzymes

Question 3

Niacin

Answer 3

Decreases hepatic synthesis of triglycerides and VLDL and reduces clearance of HDL. Niacin can decrease renal excretion of uric acid, precipitating acute gouty arthritis

Question 4

Ezetimibe

Answer 4

Selectively inhibits intestinal absorption of cholesterol. Primarily used in conjunction with station therapy for the treatment of hypercholestrolemia.

Question 5

Resting membrane potential

Answer 5

Ions that are most permeable to the cell membrane make the largest contribution of the resting membrane potential. In general, high potassium efflux and some sodium influx are responsible for the resting membrane potential , which is about -70.

Question 6

Calcineurin

Answer 6

Essential protein in the activation of IL-2, which promotes the growth and differentiation of T-cells. Immuno suppressants such as cyclosporine and tacrolimus work by inhibiting Calcineurin acticvation

Question 7

Bcl-2

Answer 7

Apoptosis inhibitor. Over expression leads to delayed cell death and accumulation of indolent malignant cells.
Follicular cell lymphomas t(14;18) translocation

Question 8

Neurofibromin

Answer 8

Tumor suppressor protein encoded by the NF1 gene on chromosome 17. Can protect against cancer as it is key suppressor of RAS, activator of cell growth and proliferation