48. 2,4-Dinitrophenol and oligomycin inhibit mitochondrial oxidative phosphorylation. 2,4-Dinitrophenol is an uncoupling agent; oligomycin blocks the ATP synthesis reaction itself. Therefore, 2,4-dinitrophenol will:
(A) allow electron transfer in the presence of oligomycin.
(B) allow oxidative phosphorylation in the presence of oligomycin.
(C) block electron transfer in the presence of oligomycin.
(D) diminish O₂ consumption in the presence of oligomycin.
(E) None of the above.

44. Which of the following enzymes catalyzes the conversion shown below? (A) Hexose isomerase (B) UDP-galactose 4-isomerase (C) UDP-galactose 4-mutase (D) Phosphoglucose mutase (E) UDP-glucose 4-epimerase

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

46. Which of the followings best describes the glycosidic bond below? (A) β(2-4) (B) α(1-3) (C) α(1-4) (D) β(1-4) (E) α(2-4)

47. Which type of columns are affected by the ionic charge, shape, substrate-binding strength of a protein, respectively? (A) Gel filtration, Affinity chromatography, Cation or anion exchange. (B) Affinity chromatography, Gel filtration, Cation or anion exchange. (C) Cation or anion exchange, Gel filtration, Affinity chromatography. (D) Gel filtration, Cation or anion exchange, Affinity chromatography. (E) Cation or anion exchange, Affinity chromatography, Gel filtration.

49. All are physiological changes initiated by glucagon   except  : (A) activation of glycogenolysis in liver. (B) stimulation of liver gluconeogenesis. (C) long-term maintenance of steady-state levels of glucose in the blood stream. (D) activation of glycogenolysis in muscles. (E) All are true.

50. A molecule such as 2,4-dinitrophenol (2,4-DNP) works to uncouple the proton gradient. Which of the following is true about 2,4-DNP? (A) 2,4-DNP is protonated in the matrix and deprotonated in the intermembrane space. (B) The presence of an uncoupler results in an increase in the activity of the TCA cycle and electron transport. (C) 2,4-DNP is a very ineffective uncoupler because its hydrophobic structure prevents it from effectively crossing lipid bilayer membranes. (D) 2,4-DNP has been used as a very effective diet aid for the past 70 years. (E) None of the above is correct.

1. Which of the following statements about the comparison between RNA and DNA synthesis processes is correct? (A) During RNA synthesis, RNA polymerase requires the removal of nucleosomes to initiate transcription, whereas DNA replication does not involve nucleosome remodeling. (B) RNA polymerase does not require proofreading during RNA synthesis, whereas DNA polymerase has 3'-5' exonuclease proofreading activity. (C) Both RNA and DNA synthesis require the binding of DnaA protein to recognize the initiation site. (D) RNA synthesis uses only dNTPs (deoxynucleotide triphosphates) as substrates, whereas DNA synthesis utilizes both NTPs (nucleotide triphosphates) and dNTPs as substrates. (E) Both RNA and DNA synthesis use DNA as a template, and neither process requires any protein-assisted initiation complex formation.

2. Which of the following is NOT a product of photosynthesis? (A) Glucose. (B) Oxygen. (C) ATP. (D) NADPH. (E) Water.

3. In patients with certain genetic diseases, a defect in the carnitine transporter can lead to which of the following conditions? (A) Fatty acids cannot enter the mitochondria for oxidation. (B) Glucose cannot enter the mitochondria for oxidation. (C) Proteins cannot enter the mitochondria. (D) ATP synthesis increases. (E) Elevation of intracellular ketone body levels.

4. Which of the following statements regarding the functions of RNA and DNA is INCORRECT? (A) DNA is primarily responsible for storing genetic information. (B) mRNA carries genetic information and is used for protein synthesis. (C) tRNA is involved in the process of protein translation. (D) rRNA is a major component of ribosomes and participates in protein synthesis. (E) miRNA can regulate gene expression but cannot degrade mRNA.