B1.2.2

Question 1

Why does transcription and translation occur

Answer 1

DNA can’t leave the nucleus of cells as it’s too big. So a copy of DNA is made called mRNA.

Question 2

Transcription process

Answer 2

DNA around a gene unzips so both strands are separated.
One strand acts as a template.
Complementary bases attach to the strand being copied.
C-G and U-A and A-T (uracyl replaces thymine)
This forms a strand of messenger mRNA
The mRNA then detaches itself from the strand and the DNA zips itself up.
The mRNA is small enough to exit the nucleus. It then travels to the ribosomes in the cytoplasm,

Question 3

What are proteins made from (amino acids)

Answer 3

Proteins are made from amino acids which join together to form different proteins determined by the type and order of amino acids.

Question 4

Translation process

Answer 4

mRNA attaches to a ribosome.
Ribosome reads the nucleotides on the mRNA in groups of 3 called codons.
At the ribosome the tRNA reads the mRNA through complementary codons and the tRNA has an anticodon.
Each anticodon codes for a specific amino acid
Ribosome continues reading the triplet code adding more and more amino acids
Amino acids join together in a chain and a protein forms.
Sequence of the amino acids determine how proteins will fold

Question 5

What does the sequence of amino acids determine

Answer 5

The sequence of amino acids determine how the protein will fold and each type of protein is a different shape.