DNA and protein synthesis Flashcards
RNA
is a single polynucleotide strand
it contains uracil (U) as a base instead of thymine.
different types of RNA
1) mRNA (messenger RNA)
2) tRNA (transfer RNA)
3) rRNA (ribosomal RNA) - Combines with proteins to make ribsosomes
Structure of mRNA
long single strand created during transcription in which the base sequence is complementary to DNA.
Each set of three bases, called the codon,
Structure of tRNA
a small molecule made up of around 80 nucleotides.
It is a single strand that is folded into a
clover leaf shape
At the opposite end is an anticodon which is specific to the amino acid
that the tRNA attaches to.
where does transcription takes place
nucleus
outline the process of transcription
1) DNA uncoils into two strands with exposed bases. One used as a template
2) free nucleotides line up next to their complementary bases and joined together by RNA polymerase
what happens to mRNA after transcription
in eukaryotic cells, pre-mRNA must be spliced to remove introns leaving only the coding regions.
then it moves out of the nucleus and attached to a ribosome
what is produced by translation
proteins
where does translation takes place
cytoplasm
