DNA and protein syntheis

Question 1

What is the genome?

Answer 1

The complete set of genetic information contained in the cells of an organism

Question 2

What is the proteome

Answer 2

The complete set of proteins that can be produced by a cell

Question 3

Describe the structure of messenger RNA (mRNA)

Answer 3

mRNA is a long, single strand
It’s base sequence is complementary to the DNA it was transcribed from

Question 4

Suggest advantage of using mRNA rather than DNA for translation

Answer 4

mRNA is shorter and contains uracil - breaks down quickly so no excess polypeptides forms
mRNA is single stranded and linear - ribosome moves along strand and tRNA bonds to exposed bases
mRNA contains no introns

Question 5

Describe the structure of transfer RNA (tRNA)

Answer 5

tRNA is a single strand of around 80 nucleotides folded into a clover leaf shape
On one end is an anti-codon, on the opposite end is an amino acid binding site

Question 6

What does transcription produce?

Answer 6

mRNA

Question 7

Where does transcription take place?

Answer 7

Nucleus

Question 8

Outline the process of transcription

Answer 8

DNA uncoils into 2 strands with exposed bases. One is used as a template
Free nucleotides line up next to their complementary bases, joined by RNA polymerase

Question 9

What happens to mRNA after transcription?

Answer 9

In eukaryotic cells, pre-mRNA must be spliced to remove introns, leaving only coding regions.
Then it moves out of the nucleus and attaches to a ribosome

Question 10

What is produced by translation?

Answer 10

Proteins

Question 11

Where does translation take place?

Answer 11

Cytoplasm (on ribosomes)

Question 12

Outline the process of translation

Answer 12

Anti-codon of tRNA attaches to complementary bases on the mRNA
Amino acids bonded to tRNA form peptide bonds, continuing to form a polypeptide chain until a stop codon is reached
This process requires ATP