Anonymous
Anonymous asked in Science & MathematicsBiology · 1 decade ago

protein synthesis and nucleic acids?

i got the following quesiton wrong on my test and we have to give the right answers for them and say why they are right and the other answer is wrong. it would help if you could answer as many quesitons as possible, but its okay if you do some. it would also be helpful if you explain why the answer is correct or how you came to that answer

1) If the DNA triplet base ACT codes fir threonine, all of the following will be true except for:

a. the codon coding for threonine is UGA

b. the tRNA carrying the amino acid threonine has the anticodon ACU

c. the anticodon ACU will complementary bind with UGA at the ribosome

d. the tRNA carrying the amino acid threonine has the anticodon UGA

e. if ACT is the fourth nucleotide triplet set in the gene (DNA) then threonine will be the fourth amino acid in the polypeptide chain

2) TAC CAC GAC TTC

A base substitution occurs to the fourth base in the DNA strand above. The fourth base now read T rather than C. What polypeptide sequence will it code for?

a. methionine-valine-leucine-lysine

b. meth-asparagine-leu-lys

c. meth-meth-leu-lys

d. val-leu-lys

e. meth-leu-lys

3) In terms of the polypeptide that they code for, which of the four is most similar to the sequence below?

TAC TTT TTG CTC ATC

a. ATC TTT TTG CTC ATC

b. TAC TTC TTA CTT ATC

c. TAC TTC TTG CTG ATC

d. TAC TTC TAG CTC ATC

4) In trying to determine whether DNA or protein was the genetic material, Al Hershey and Martha Chasemade use of which of the following facts?

a. DNA does not contain sulfur, whereas protein does

b. DNA contains phosphorous, but protein does not

c. DNA contains greater amounts of nitrogen than does protein

d. a and b only

e. a, b, c

1 Answer

Relevance
  • 1234
    Lv 4
    1 decade ago
    Favorite Answer

    1) e. if ACT is the fourth nucleotide triplet set in the gene (DNA) then threonine will be the fourth amino acid in the polypeptide chain

    False--If it is the fourth, it will be the third amino acid. Don't forget about the start codon!

    2) d. val-leu-lys

    Take the DNA and change it to mRNA: AUG GUG CUG AAG. Use the amino acid table to get start-val-leu-lys

    3) b. TAC TTC TTA CTT ATC

    Once again, change to mRNA: AUG AAA AAC GAG UAG for original and AUG AAG AAU GAG UAG for the second. AAA=AAG, AAC=AAU, GAG=GAA in what amino acid it codes for.

    4)I don't know anything about the last question, sorry!

    Hope this helps somewhat!

Still have questions? Get your answers by asking now.