1. What is codon? (1pt)

     2. What is an anti-codon? (1pt)

     3. What tRNA bases can be attached to the mRNA codon, UGC? (1pt)

     4. Where do the amino acids in the cytoplasm of a cell come from? (1pt)

E. Complete the mRNA strand by providing the proper nitrogen bases: (1pt)

F. Complete the anti-codons for the tRNAs: (1pt)

Considering the two types of nucleic acids, how does RNA differ from DNA?

a) RNA is double-stranded; DNA is single-stranded.

b) RNA is a polymer of amino acids; DNA is a polymer of nucleotides.

c) In RNA G pairs with T; in DNA G pairs with C.

d) RNA contains uracil; DNA contains thymine.

1 (met) 2 (asp)    3 (gly) 4 (glu)    5 (trp)

The following pentapeptide MET-ASP-GLY-GLU-TRP is initially treated with cyanogen Bromide, and subsequently treated with Chymotrypsin. Based on this information, answer the following: Identify the carboxyl and amino terminus of the pentapeptide before treatment and indicate if terminal side chain groups are ionizable? If applicable, indicate which reagents result in chemical cleavage or enzymatic cleavage. Biochemical approaches can be used to determine the differences in the peptide before and after treatment. Indicate two biochemical approaches and what is being analyzed using this approach. Indicate any free amino acids and/or peptide fragments that result after cyanogen bromide treatment. If applicable, indicate any free amino acids and/or peptide fragment sequences that result after cyanogen bromide treatment and subsequent treatment with chymotrypsin.

What is the maximum number of amino acids that could result from the following mRNA sequence?

5′ AUGAGACCGUCG 3′

A.    0

B.    4

C.    7

D.    10

Insulin sequence As reported in 1945, Sanger reacted insulin with FDNB and hydrolyzed the resulting protein. He found many free amino acids, but only three DNB-aa

31. Which of the following describes the distribution of the polar and nonpolar portions of lipids in the lipid bilayer? A). Both polar heads are on the inside of the bilayer and both hydrophobic tails are on the outside of the bilayer. B). Both polar heads are on the outside of the bilayer and both hydrophobic tails are on the inside of the bilayer. C). Both the inside and outside of the bilayer consist of alternating polar heads and nonpolar tails. D). Some polar heads are on the inside of the bilayer and some are on the outside; the hydrophobic tails are similarly distributed.

33. Which describes the isoelectric point of an amino acid? A). The degree of ionization of the amino acid at pH 7. B). The pH at which there is no net charge for the amino acid. C). The pH at which the ionized form predominates. D). The pH at which the amino acid is present as the dipolar ion. CH2 – CONH2 

34. Asparagine (Asn) has an isoelectric point (pI) of 5.4, (H3N+ ¾CH¾COO- ). Select the correct Zwitterion structure of asparagine in a solution with a pH of 10. CH2 – CONH2 CH2– CONH2   A). H2N¾CH¾COO- B). H3N+ ¾CH¾COOH CH2– CONH2 CH2– CONH2   C). H2N¾CH¾COOH D). H3N+¾CH¾COO-

35. Which functional group is involved in linking together the amino acids of proteins? A). amine B). anhydride C). carbonyl D). carboxyl

36. Select the correct three-letter abbreviation for the order of amino acids in this tripeptide. O H O H O      H3N+  CH  C  N  CH  C  N  CHCO-    CH2OH CH3 H A). AlaGlySer B). GlySerAla C). SerAlaGly D). AlaSerGly

37. The secondary structure of proteins depends primarily on which property of amino acids? A). disulfide bonds B). hydrogen bonds C). amide bonds D). polar side chains

38. The beta-pleated sheet represents what level of protein structure? A). Primary B). Secondary C). Tertiary D). Quaternary

39. The following will denature proteins EXCEPT A). Agitation B). Acids and bases C). Heavy metal ions D). Freezing temperature

40. Which of the following is a structural protein? A). cellulose B). collagen C). hemoglobin D). insulin

41. In which of the following is the amino nitrogen also part of the side chain? A). cysteine B). glycine C). proline D). tryptophan

Iron-sulphur proteins contain:

a. amino acids, haem and ribose

b. iron, ribose and sulphur but no haem

c. iron, amino acids and sulphur plus haem

d. iron, amino acids and sulphur but no haem

Which reaction occurs in the citric acid cycle?

a. Lactate is reduced to form NAD+

b. Fumarate is hydrolysed to form malate

c. Glyceraldhyde-3P is oxidised to form NADH + H+

d. Fumarate is hydrolysed to form H2O and NADH + H+

What is the function of mitochondrial ATP synthase?

a. It produces ATP using the electrochemical potential of mitochondria.

b. It produces ATP using phosphoenolpyruvate and ADP as substrates

c. It produces ATP using the electrochemical potential of the plasma membrane.

d. It reduces lactate to pyruvate using ADP as a substrate.

During photosynthesis the light harvesting reactions takes place:

a. in mitochondria using the mitochondrial ATP synthase and light.

b. in chloroplasts using photosystem I, mitochondrial ATP synthase plus light for its reactions.

c. in chloroplast using photosystem I alone but not photosystem II.

d. in two steps using two different photosystems, photosystem I and II.

1. Which of the following statements is FALSE?

A. The amino acid pool is the body's total supply of amino acids in the body's proteins.

B. Fats and carbohydrates are oxidized directly to produce cellular energy.

C.Amino acids can be used to supply energy only after being converted to a citric acid cycle intermediate.

D. Excess carbohydrate and fat can be stored as such, whereas excess amino acids are oxidized for energy or converted to fat or glycogen for storage.

2. If you were to jog one kilometer a few hours after lunch, which stored fuel would you probably tap?

A. muscle proteins

B. blood proteins

C. fat stored in adipose tissue

D.liver glycogen and muscle glycogen

3.A fasting animal whose energy needs exceed those provided in its diet will draw on its stored resources in which order? (See slides 81-82 in the Exam 3 review PowerPoint.)

A.fat, then glycogen, then protein

B. glycogen, then protein, then fat

C. liver glycogen, then muscle glycogen, then fat

D. muscle glycogen, then fat, then liver glycogen