protein synthesis Flashcards
what holds the “master plan” for protein making?
DNA
why is protein important?
it is required by almost all cell processes
how do proteins function?
as enzymes, therefore controlling chemical reactions of the cell
what are the two stages of protein synthesis?
transcription
translation
what is transcription and where does it occur?
where DNA code is transcribed to a RNA molecule
occurs inside the nucleus
what is the DNA code?
a sequence of bases (A, T, G, C) each triplet (codon) of bases corresponds to one amino acid
what is translation and where does it occur?
where RNA code (from nucleus) is translated into a specific sequence of amino acids by ribosomes
occurs in the cytoplasm
steps of protein synthesis
step 1
DNA is transcribed (copied) onto a complementary strand of DNA
steps of protein synthesis step 2 (after DNA is transcribed (copied) onto a complementary strand of DNA)
mRNA takes the coded message to ribosomes in the cytoplasm
steps of protein synthesis step 3 (after mRNA takes the coded message to ribosomes in the cytoplasm)
mRNA attaches to a ribosome, where its coded message can be translated
steps of protein synthesis step 4 (after mRNA attaches to a ribosome, where its coded message can be translated)
a tRNA molecule transfers a specific amino acid to the ribosome
steps of protein synthesis step 5 (after a tRNA molecule transfers a specific amino acid to the ribosome)
the incoming tRNA attaches to the mRNA, which allows the tRNA amino acid to bond to the polypeptide chain
steps of protein synthesis step 6 (after the incoming tRNA attaches to the mRNA, which allows the tRNA amino acid to bond to the polypeptide chain)
when the ribosome moves along the mRNA, the tRNA released can pick p another amino acid
steps of protein synthesis step 7 (after when the ribosome moves along the mRNA, the tRNA released can pick p another amino acid)
translation complete, a ribosome releases the finished polypeptide and the mRNA
