DNA to Proteins

Question 1

What is a Svedberg?

Answer 1

Refers to mass and shape of cellular organelle (^S = ^ Mass)

Question 2

Role of 3 types of RNA?

Also 5’ to 3’

Answer 2

1) mRNA: Make genes, act as messenger
2) rRNA: Structural, builds ribosomes (mix of protein and rna)
3) tRNA: Translation, covalently linked to corresponding AA and carry it to a ribosome

Question 3

What happens if can’t find a tRNA?

Answer 3

Coding stops, ribosome falls apart, complex released and degraded

Question 4

How does tRNA bond to AA?

Answer 4

Anticodon on loop exposed and binds to complementary codon via HB

Question 5

What do patterns of sequences allow us to see?

Answer 5

Splice junctions, where to cleave and cut mRNA

Question 6

How to work out number of combinations based on base number?

Answer 6

E.g. 4 bases, so combinations are 4 cubed, so 64

Question 7

3 properties of Genetic Code?

Answer 7

1) Degenerate: More than one code for an AA
2) almost universal (exclude mitochondria)
3) Non overlapping: Only read once

Question 8

Where do Transcription Factors target?

Answer 8

Promoter region (5’ of 1st exon), leads to DNA strand separation and production of mRNA

Question 9

What can turn off DNA expression?

Answer 9

Repressor (Inhibit RNA polymerase), so transcription doesn’t occur, so complexes don’t form, no enzymes activated

Question 10

Process of reverse transcriptase?

Answer 10

DNA converted to RNA converted to a Protein