Ch:17 Translation Flashcards
Where does transcription occur and where does translation occur?
Transcription occurs in the nucleus
Translation occurs in the cytosol
How many tRNA’s do we need if we have 300 amino acids?
300 tRNA’s
each tRNA is specific for a particular amino acid
What is the start codon?
AUG which codes for the amino acid methionine
How many mRNA and tRNA binding sites are on a ribosome?
1 mRNA
3 tRNA (A, P, E) - polypeptide synthesis only occurs on either P or A site
Differentiate between the 2 tRNA binding sites:
- P site
- A site
P site: holds the tRNA attached to the growing polypeptide
(P = growing Polypeptide) (AUG is at the P site)
A site: holds the tRNA with its associated amino acids to the polypeptide chain
(A = Associated amino acids)
Give an overview of Translation:
Translation is the synthesis of a protein from an mRNA template where the code in the mRNA is converted into an amino acid sequence in a protein.
If a single base pair of gene is affected it is a _____ mutation.
Point mutation
What is the difference between a missense mutation and a nonsense mutation?
Missense mutations occur if a wrong amino acid is made
Nonsense mutations occur if a stop codon is made
“TWO MUST HAVE MUTATIONS YOU NEED TO KNOW FOR THE DAT!!!”
What is a frameshift mutation?
Reading frame changes due to an insertion or deletion of nucleotide pairs in a gene
What are transposons?
“jumping genes” which may cause a mutation when they “jump” around the genome
A chemical or physical agent that can interact with DNA and cause a mutation is called a ______.
Mutagen
eg. UV radiation
If DNA coding sequence is CCGAGT, the anticodon on the tRNA that binds the mRNA codon will be?
If DNA is CCGAGT, then mRNA is GGCUCA thus tRNA is CCGAGU
(remember mRNA is an RNA! so it will have uracil instead of thiamine)
“GK DAT”
In mRNA, every three nucleotide bases is a ______.
Codon
1 codon = 3 mRNA nucleotides
1 codon = 1 amino acid
