4.2 DNA and protein Synthesis Flashcards
What is the genome
The complete set of genetic information stored within the cells of an organism
What is the proteome
The complete set of proteins that can be produced by a cell
Describe the structure of messenger RNA (mRNA)
mRNA is a long single strand which its base sequence is complementary to the DNA it is transcribed from
Suggest advantages of using mRNA rather than DNA for translation
Shorter and contains uracil therefore break down quickly so no excess polypeptide forms
Single standed and linear so ribosome moves along the strand and tRNA bonds to exposed bases
Contains no introns
Describe the structure of transfer RNA (tRNA)
tRNA is a single strand of around 80 nucleotides that is folded over into a clover leaf shape. One end is an anti codon region, the other is an amino acid binding site
What is produced by transcription
mRNA
Where does transcription take place
In the nucleus
Outline the process of transcription
DNA uncoils into two strands with exposed bases. One used as a template
Free nucleotides line up next to their complementary bases, and are joined together by RNA polymerase
What happens to mRNA after transcription
In eukaryotic cells, pre-mRNA is spliced to remove introns, leaving only the coding region. It then moves out of the nucleus and attaches to a ribosome
What is produced by translation
Proteins
Where does translation take place
In the cytoplasm (on ribosomes)
Outline process of translation
The anti-codon of tRNA attaches to complementary bases on the mRNA
Amino acids bonded to tRNA form peptide bonds, continuing to form a polypeptide chain until a stop codon is reached
This process requires ATP
