5) Which of the following are true of the structure of proteins?
a) Polypeptides consist of a series of amino acids, always arranged in a single, unbranched chain.
b) The secondary structure of proteins is always in the form of two helices wound around each other.
c) Only regulatory proteins have tertiary structure.
d) Quaternary structure describes how multiple polypeptides combine to form a single unit.
e) a and d
f) b and c
g) a, b, and c
h) a, b, and d
6) The following mRNA codons encode the amino acid arginine:
5'-CGU 5'-CGC 5'-CGA 5'-CGG 5'-AGA 5'-AGG
In light of this, which of the following are true?
a) Due to "wobble", these codons could all bind to a single tRNA.
b) Because only the first base of the codon can "wobble", there must be at least four tRNAs for arginine.
c) Because only the third base of the codon can "wobble", there must be at least two tRNAs for arginine.
d) The following are both possible anti-codons for an arginine tRNA: 5'-UCU, 5'-CCU
e) both a and d
f) both b and d
g) both c and d
7) You are studying a mutant fruit fly that has a two-base-pair deletion in the third exon of its GADPH gene. Which of the following could be true of your mutant?
a) Although one or two codons will be affected by this mutation, it will not cause a shift in the reading frame because more than one base pair was deleted.
b) Since the mutation only occurs in an exon, it will be a neutral mutation.
c) This mutation could be a spontaneous mutation caused by strand slippage during DNA replication
d) Since the mutation is a deletion, it will not be passed on to any offspring the fly has.
e) none of the above
f) both a and b
g) both b and c
h) both c and d