28. Fatty acids are released from adipocytes when:
(A) insulin levels are high,
(B) glycerol-3-phosphate levels are high,
(C) blood glucose levels are low adiposc ATP levels are high,
(D) adipose ATP levels are high,
(E) none are true.

24. In the electron transport system of mitochondria, the hydrophobic mobile carrier of electron (A) cytochrome a, (B) cytochrome c, (C) FAD, (D) ubiquinone, (E) cytochrome b.

25. Succinyl-CoA within TCA cycle provides most of the carbon atoms in the biosynthesis of _. (A) porphyrins, (B) fatty acids, (C) steroids, (D) cysteine, (E) lysine.

26. Insulin carries a cellular responsibility to reduce blood glucose as well as________. (A) stimulates gluconeogenesis, (B) inhibits glycolysis, (C) stimulates glycogen synthesis in muscle and liver, (D) stimulates glycogen breakdown in liver, (E) inhibits phosphoprotein phosphatase-1.

27. Ethanol metabolism in liver is characterized by all of the following EXCEPT: (A) decreased pH levels due to lactic acidosis, (B) decreased NADH/NAD+ ratio in the cell, (C) decreased gluconeogenesis activity resulting in hypoglycemia, (D) two oxidation steps to convert ethanol to acetate, both reactions produce NADH, (E) increased acetaldehyde-protein adducts impairing protein function.

29. All of the following are fuels for contracting muscles during anaerobic metabolism EXCEPT: (A) ATP, (B) palmitic acid, (C) glycogen, (D) glucose, (E) creatine phosphate.

30. Herbicides (e.g., "Roundup") inhibit biosynthesis of 'essential" amino acids because animals do not have enzymes of: (A) photosynthesis, (B) glyoxylate cycle, (C) glutamine synthesis pathway, (D) Phe, Val, Leu, Ile and His biosynthetic pathways, (E) none of above.

1. Which of the following is NOT part of the endomembrane system? (A) Lysosome (B) Endoplasmic reticulum (C) Golgi apparatus (D) Mitochondria

2. In a natural community, the primary consumer is? (A) Carnivores (B) Herbivores (C) Detritivores (D) Decomposers

3. Which of the following statement about enzyme is NOT TRUE? (A) All enzymes' are proteins (B) The active site is the region where the substrate binds (C) Each enzyme has an optimal temperature and pH in which it can function (D) Optimal conditions usually favor the most stable and active conformation for the enzyme molecule

4. What is the central role of helper 'T cells? (A) Helper T cells are the only immune cell type that can produce immunological memory (B) Activated helper T cells release perforin that make pores in the target cell's membrane and enzymes promoting apoptosis leading to cell death (C) Helper T cells can be activated through innate immune response by antigen- presenting cells such as macrophages and dendritic cells, setting stage for the adaptive immune response (D) Activated helper T cells-Lan produce antibodies