rRNA, tRNA, and Genetic Cod

Question 1

rRNAs are transcribed by RNA polymerase ____ (I, II, or III?)

Answer 1

I

Question 2

______ are the catalyst of protein synthesis inside ribosomes.

Answer 2

rRNAs

Question 3

The two subunits of a eukaryotic ribosome are ____ and ____ = 80S

Answer 3

60S and 40S

Question 4

we need _______ ribosomes per cell to make all the proteins that are required

Answer 4

10 million

Question 5

rRNAs are transcribed, modified and assembled into ribosomes in the ____.

Answer 5

Nucleolus

Question 6

______ bring the amino acids to the ribosome. They also decode the mRNA sequence by reading a group of 3 nucleotides called a _____.

Answer 6

tRNAs
Codon

Question 7

There are ____ different possible codons. There are only ____ amino acids, therefore the same amino acid will have several different codons. One exception is, methionine which has only one codon: _____, which is also a start codon

Answer 7

64
20
AUG

Question 8

Three stop codons are ____, ____, ____ and do not code for any amino acids.

Answer 8

UAA
UAG
UGA

Question 9

The genetic code is ____ meaning most amino acids have more than one codon. It is also ____ meaning each codon only codes for one amino acid. This genetic code is almost _____.

Answer 9

Degenerate
Unambiguous
Universal

Question 10

One single nucleotide insertion error will cause a ____ ____.
This can lead to a premature stop codon. This is called a _____ mutation.

Answer 10

Frameshift
Nonsense

Question 11

Another single nucleotide error can lead to a ______ mutation, where the wrong amino acid is added to the protein. No frameshift in this mutation.

Answer 11

Missense

Question 12

tRNAs are transcribed by RNA polymerase _____.

Answer 12

III

Question 13

tRNAs are heavily modified before they exit the nucleus. Example, Two ____ groups are added to guanine. Sulfur is replaced by _____ in U.

Answer 13

Methyl
Oxygen

Question 14

The ____ structure of tRNA looks like a clover leaf. The 5’ end of the RNA base pairs and binds to the 3’ end.

Answer 14

Secondary

Question 15

The T loop and D loop interact to form the _____ structure for the tRNA.

Answer 15

Tertiary

Question 16

The ______ on the tRNA has three nucleotides that are complementary to the codon on the mRNA

Answer 16

Anticodon

Question 17

On a tRNA, an ____ ____ attaches to the 3’ prime end sequence of __ __ __.

Answer 17

Amino acid
CCA (can carry amino acid)

Question 18

_____ _____ charges the tRNA with the correct amino acid. It also has proof reading abilities.

Answer 18

tRNA synthetase

Question 19

After taking the 3 stops codons out, there are ____ codons that code for amino acids. There are ___ tRNAs, some amino acids have more than one tRNA. some tRNAs allow for mismatch _____ at the third codon position.

Answer 19

61
48
Wobble

Question 20

Take home message

Answer 20

Review

Question 21

A point mutation resulting in a stop codon is ___.
A point mutation resulting in an amino acid change is _____.
A mutation resulting in a shift in origin reading frame is ____.
A point mutation resulting in no amino acid change is _____.

Answer 21

Nonsense mutation
Missense mutation
Frame shift mutation
Silent mutation

Question 22

Answer 22