During RNA processing a(n) _____ is added to the 5' end of the RNA.
modified guanine nucleotide- the 5' cap consists of a modified guanine nucleotide
During RNA processing a(n) is added to the 3' end of the RNA.
a long string of adenine nucleotides- A poly-A tail is added to the 3' end of the RNA.
Translation occurs in the _____.
cytoplasm- ribosomes, the sites of translations, are found in the cytoplasm
The tRNA anticodon, GAC, is complementary to the mRNA codon with the sequence _____.
CUG- in RNA uracil replaces thymine
Generally speaking, which of the following mutations would most severely affect the protein coded for by a gene?
a frameshift deletion at the beginning of the gene- it would affect every codon after the point where the mutation occurred. During protein synthesis, incorrect amino acids would be inserted from the point where the frameshift mutation occurred on; the resulting protein would most probably be nonfunctional. For this reason, a frameshift mutation at the beginning of a gene is generally the most severe type of mutation.
True of false? A codon is a group of three bases that can specify more than one amino acid.
False- a codon is a group of three bases that can specify only one amino acid
Which of the following statements about mutations is false?
A knock-out mutation results in a total absence of the mutated protein.- a knock out mutation refers to the loss of a protein's function but not necessarily to its complete absence.
If a DNA sequence is altered from TAGCTGA to TAGTGA, what kind of mutation has occurred?
Deletion- the original sequence has lost the base C
Which mutation(s) would not change the remainder of the reading frame of a gene sequence that follows the mutation(s)?
one addition and one deletion mutation.
If the sequence ATGCATGTCAATTGA were mutated such that a base were inserted after the first G and the third T were deleted, how many amino acids would be changed in the mutant protein?
Two- the second and third codons in the new sequence are different from the original codons.
If a mutated DNA sequence produces a protein that differs in one central amino acid from the normal protein, which of the following kinds of mutations could have occurred?
An addition mutation and a deletion mutation.
A change in any triplet of bases in the mRNA sequence may or may not affect the coding of a(n) _____ and change the structure of the synthesized protein.
A _____ mutation results in the insertion of the same amino acid as was coded for by the original nucleotide sequence
A _____ mutation can dramatically alter protein structure because it results in the insertion of a different amino acid than was coded for by the original nucleotide sequence.
the new base changes an amino acid codon to a stop codon, ending protein synthesis and resulting in a shorter and usually nonfunctional protein
the new base leads to the insertion of a different amino acid than had been coded for, possibly altering the resulting protein's structure.