Protein Synthesis Flashcards
1
Q
What is a Codon
A
3 Bases that code for a certain protein
2
Q
what does a codon do?
A
- codes for a specific amino acid
-therefore the sequence of bases is like a set of instructions which has the order of amino acids to make a protein
3
Q
what effects the protein produced in protein synthesis?
A
- Sequence of bases in the mRNA
4
Q
Describe the process of transcription
A
- two stands of DNA helix unwound by RNA polymerase
- Enzyme RNA polymerase attaches to DNA just before the gene
- RNA polymerase moves along DNA strands, and free RNA nucleotides are attracted to the exposed DNA strand nucleotides due to complimentary base pairing
- RNA polymerase then catalyses the formation of covalent bonds between RNA nucleotides to form a strand of mRNA- this strand is a complementary copy of the DNA strand (except U replaces T)
- newly formed strand of mRNA is now ready to leave nucleus and travel to ribosome
5
Q
What does the base Uracil (U) pair with?
A
- adenine
6
Q
describe process of translation
A
- tRNA transport specific amino acids to ribosome
- anticodon at bottom of tRNA molecule bind to complimentary codon in mRNA strand
- this causes mRNA codon to determine the amino acid attached (to tRNA as anticodon is bound specifically)creating amino acid chain
- a chain of several hundred amino acids forms (in the correct order according to original DNA)
-this is called a polypeptide - after translation, polypeptide is folded into correct shape and becomes a protein
- function of protein depends on shape of polypeptide
7
Q
examples of codon and anticodon
A
- if codon is CGG, anticodon is GCC
8
Q
what is a triplet code
A
- the 3 mRNA/tRNA bases (codon)’s letters, eg GCC
9
Q
where does transcription occur
A
in the nucleus
10
Q
where does translation occur
A
in the ribosomes
