複選題
31. Which of the following amino acids absorb UV (280nm)?
(A) Tyrosine
(B) Tryptophan,
(C) Glutamine
(D) Valine
(E) Phenylalanine

複選題27. Intracellular second messengers include all of the following? (A) Ca2+. (B) diacylglycerol (DAG). (C) cATP. (D) nitric oxide (NO). (E) cGMP

複選題28. Which of the following statements is/are TRUE? (A) A nucleosome contains 6 histones within its core. (B) Chromatin is composed of DNA and protein. (C) Nucleosomes are composed of about 100 bp of DNA wrapped around a histone core. (D) DNA methylation is the only known natural modification of DNA. It affects cytosine bases. (E) Histones have highly conserved sequences among eukaryotes.

複選題29. Which of the following residues can be phosphorylated by protein kinases? (A) Serine (B) Lysine (C) Threonine (D) Tyrosine (E) Alanine.

複選題30.Which of the following statements is/are TRUE of supercoiling? (A) The relaxed form of DNA is more stable and is therefore the preferred form in the cell. (B) Most organisms maintain their DNA in a slightly overwound state in order to enhance strand separation during transcription and replication. (C) Overwound DNA is in the B form so relaxed DNA has less turns than B-form DNA. (D) Most organisms maintain their DNA in a slightly underwound state in order to compact their DNA. (E) The relaxed form of DNA can only be maintained if the DNA is a closed circle.

複選題32.Which of the following lipids are the general constituents of plasma membrane bilayer? (A)Phosphatidylcholine (B) Triacylglycerol (C) Free fatty acids (D) Glycolipid (E)Phosphatidylethanolamine

33.Which of the following molecules have the catalytic function in the biological system (A) DNA (B) RNA (C) Lipid (D) Carbohydrate (E) Protein

34.Prokaryotes and eukaryotes are similar in having (A) cell membrane (B) mitochondria (C) Golgi (D) nuclear membrane (E) chromosome

複選題35. Transcriptional activation of enzymes specified for the utilization of lactose as a carbon source in E. coli requires the small-molecule signals by changing the DNA binding activity of two proteins, one being inactivated and the other activated. They are controlled by binding with (A) c-AMP (B) ATP (C) Lactose or 1,6-Allolactose (D) Isopropyl-thiogalactoside (IPTG) (E) glucose

36. The building blocks of RNA molecules are (A) Adenylate (B) cytidylate (C) Guanylate (D) Thymidylate (E) Uridylate

複選題37.Which of the following biomolecules have the reducing function in the biological system? (A) Glutathione (B) NAD+ (C) NADP+ (D) FADH2 (E) Vitamin C