Protien Synthesis

Question 0

Where does transcription take place?

Answer 0

In the cell nucleus

Question 1

What determines which amino acids are created?

Answer 1

The sequence of bases

Question 2

What are the stages of transcription?

Answer 2

1. The DNA unzips so both strands are separate, one strand is used as a template
2. Bases attach to the strand being copied
3. Thymine (T) is not present so ‘U’ is used to join with ‘A’ instead
4. The strand forms mRNA

mRNA is small enough to go out of the nucleus to the ribosomes.

Question 3

Where does translation occur?

Answer 3

The ribosomes

Question 4

What happens to the mRNA at the ribosome?

Answer 4

It gets ‘interpreted’ and a new protein forms

Question 5

What are the stages of translation?

Answer 5

1. The mRNA attaches to a ribosome, the ribosome ‘reads’ to mRNA
2. The ribosome decides the mRNA in groups of three - base triplets or codons - which are complimentary to bases in transfer RNA (tRNA)
3. The tRNA is specific to an amino acid that if collects and returns to the mRNA
4. The amino acids are now lined up in order of the instructions on the mRNA
5. Bonds form between the amino acids and a polypeptide chain is formed
6. The polypeptide chain folds and becomes a specific shape forming a protein

Question 6

What is a mutation?

Answer 6

Changes that occur in genes

Question 7

How are mutations caused?

Answer 7

Background radiation and chemicals that we come into contact with e.g. the chemicals in cigarette smoke

Question 8

How does a mutation get passed on?

Answer 8

If the mutation happens in sex cells they can be passed on to later generations

If the mutation happens in a normal body cell the changes are lost when we die