Lecture 17 Flashcards
1
Q
What are the key features of the genetic code
A
- 61 of possible 64 codons specify an amino acid
- most amino’s have more than one codon
- three codons specify stop (UAA, UAG, UGA)
- one specifies start (AUG– methionine)
2
Q
What is tRNA (transfer)
A
the adaptor molecule
- single RNA strand
- at least one tRNA for each amino acid
- has a region that binds with amino and one that interacts with mRNA
3
Q
How is a tRNA molecule charged
A
an enzyme recognises both specific amino acid and correct tRNA for amino acid and joins them together
4
Q
how many tRNA charging enzymes are there
A
20- one for each amino acid
5
Q
What is Translation
A
the synthesis of protons by using mRNA as a set of instructions
ribosomes contain both Ribosomal RNA and protiens
6
Q
What are the 3 stages of translation
A
initiation, elongation, termination
7
Q
What is a Genotype
A
- sets of genes/DNA combinations that are responsible for a particular trait
- Determined at DNA level
8
Q
What is a Phenotype
A
- the physical expression or characteristics of a genotype
- defined by what happens at the protein level
