DNA and protein synthesis (8) Flashcards
What is the genome?
complete set of genetic information contained in the cells of an organism
What is the proteome?
complete set of proteins that can be produced by an organism
What is the structure of mRNA?
- long
- single-strand
- base sequence complementary to the DNA it was transcribed from
What are 3 advantages of using mRNA rather than DNA for translation?
1) shorter + contains uracil
2) single-stranded and linear
3) contains no introns
How is being short and containing uracil an advantage in translation?
breaks down quickly so no excess polypeptide forms
How is being single-stranded and linear an advantage in translation?
ribosome moves along strand and tRNA binds to exposed bases
What is the structure of tRNA?
- single strand
- around 80 nucleotides
- folded over into clover shape
- one end has an anti-codon and opposite end has amino acid binding site
What does transcription produce?
mRNA
Where does transcription occur?
nucleus
What are the 2 steps of transcription?
1) DNA uncoils into 2 strands with exposed bases, 1 is used as a template
2) free nucleotides line up next to complementary bases and are joined together by RNA polymerase
What happens to mRNA after trancription?
in eukaryotic cells, pre-mRNA must be spliced to remove introns, leaving only coding regions, then it moves out of the nucleus and attaches to a ribosome
What does translation produce?
proteins
Where does translation occur?
in cytoplasm on ribosomes
What are the 2 steps of translation?
1) anti-codon of tRNA attaches to complementary bases on mRNA
2) amino acids bonded to tRNA form peptide bonds, continuing to form a polypeptide chain until a stop codon is reached
What does translation require?
ATP
