14 PROTEIN SYNTHESIS + MUTATIONS Flashcards
1
Q
What is a mutation
A
A rare and random change in the sequence of a base in DNA
2
Q
What is the job of mRNA
A
To copy a sequence of DNA bases
3
Q
Where does transcription occur
A
In the nucleus
4
Q
Describe the process of transcription
A
- The two strands of DNA are unzipped
- mRNA makes a copy of the bases, using uracil instead of thymine
- The mRNA leaves the nucleus into the cytoplasm
5
Q
Describe the process of translation
A
- mRNA strand travels through the cytoplasm and into the ribosome
- Ribosome moves along mRNA strand and reads it’s codons
- The ribosome lines up tRNA for each mRNA to bind to
- There are 3 mRNA bases for each tRNA molecule - Triplet code
- tRNA molecules moves amino acids to the ribosome
- Amino-acid chain is produced
6
Q
Commonality of mutations
A
They are rare events
7
Q
How are mutations inherited
A
If the mutation occurs during meiosis in gamete formation
8
Q
What is a non-inherited mutation
A
If the mutation occurs in a body cell
9
Q
How is the risk of mutations increased
A
- Ionising radiations - gamma and x-rays
- Chemicals- tobacco
