4.2 - DNA and protein synthesis

Question 1

Define genome

Answer 1

The complete set of genes in cell

Question 2

Define proteome

Answer 2

The full range of proteins a cell is able to produce

Question 3

Draw a diagram of messenger RNA and describe its structure

Answer 3

Linear
Has no hydrogen bonds
No amino acid binding site
More nucleotides than tRNA
Different mRNAs have different lengths
Has codon

Question 4

Draw a diagram of transfer RNA and describe its structure

Answer 4

Clover leaf shape
Has hydrogen bonds
Has an amino acid binding site
All tRNAs are similar lengths
Has anticodon

Question 5

What is transcription?

Answer 5

The production of mRNA from DNA

Question 6

Describe the process of transcription

Answer 6

Hydrogen bonds between complementary DNA bases break so DNA strands separate
One DNA strand acts as a template
Free RNA nucleotides form complementary base pairs
RNA polymerase joins mRNA nucleotides by phosphodiester bonds
Prokaryotes: mRNA made
Eukaryotes: premRNA made, which is then spliced to form mRNA

Question 7

What is splicing?

Answer 7

The removal of introns from a base sequence

Question 8

What is translation?

Answer 8

The production of polypeptides from the sequence of codons carried by mRNA

Question 9

Describe the process of translation

Answer 9

mRNA associated with ribosome
Ribosome finds start codon
tRNA brings specific amino acid to ribosome
Anticodon binds to complementary codon
Amino acids join by peptide bonds in condensation reaction using ATP
tRNA released
Ribosome moves along mRNA to form polypeptide

Question 10

Name the type of bond between complementary base pairs in DNA and adjacent nucleotides

Answer 10

Hydrogen bonds
Phosphodiester bonds