protein synthesis Flashcards
transcription location (3)
transcription happens in the nucleus. mrna strnads are transcribed from dna by an enzyme named rna polymerase. new mrna sequences are complementary to their dna template, rather than being identical copies to the template.
transcription process (7)
1 dna strands unwind and unzip
2 hydrogen bonds break
3 one strand is used as atemplate to form mrna using free nucleotides from the nucleoplasm
4 the coded message for protein synthesis is copied onto the mrna
5 the mrna moves out of the nucleus through a nucleopore
6 the mrna carries triplet codes for dna called codons
7 the mrna attaches itself to a ribosome
translation location (2)
translation happens in the cytoplasm. rna is translated into protein by ribosomes.
translation process (6)
1 in the cytoplasm are trna (anticodons)
2 trna collect free floating amino acids in the cytoplasm to form the anticodon
3 the trna moves to the ribosome where the mrna strands have attached
4 the anticodons on the trna match the bases on the codons of the mrna
5 amino acids carried by trna become attached by peptide bonds to form the required protein
6 each trna is released to pick up more amino acids
translation from mrna to protein (4)
1 the mrna strand attaches itself to ribosomes in the cell
2 a trna molecule transfers an amino acid to the ribosome in a sequence determined by the mrna codons. this is done through a system of complementary codons and anticodons. each trna carries only one anticodon, which complements a specific mrna codon.
3 the mrna codon carries a code for a specific amino acid. an anticodon is a sequence of three bases found on trna. each new amino acid links with the previous amino acid by forming a peptide bond, resulting in an amino acid chain.the amino acid chain lengthens into a polypeptide in a process called elongation.
4 after the polypeptide chain is synthesised, the protein is formed by processes such as combing different polypeptide chains and protein folding
