Protein synthesis Flashcards
What is a gene
sequence of nucleotide bases in a DNA molecule that codes for the production of a specific sequence of amino acids, that make a polypeptide
What are the two stages of protein synthesis
Transcription – DNA is transcribed and an mRNA molecule is produced
Translation – mRNA is translated and an amino acid sequence is produced
what are the differences of RNA and DNA
RNA contains a ribose sugar while DNA contains deoxyribose
RNA is usually single-stranded while DNA is double-stranded
RNA contains the base uracil instead of the DNA base thymine
Where does transcription occur
occurs in the nucleus of the cell
What is the first step to transcription
DNA molecule unwinds and the hydrogen bonds between the complementary base pairs break
what happens after the DNA molecule unwinds
A complimentary copy of the code from the gene is made known as mRNA
This reaction is catalysed by RNA polymerase
What happens after mRNA is created
the hydrogen bonds between the mRNA and DNA strands break and the double-stranded DNA molecule reforms
What happens after the double-stranded DNA molecule reforms
The mRNA molecule then leaves the nucleus via a pore in the nuclear envelope
what is the antisense strand
template strand used to produce the mRNA molecule
what direction does the RNA polymerase move
moves along template strand in the 3’ to 5’ direction
Where does translation occur
in the cytoplasm of the cell
What happens after leaving the nucleus via a nuclear pore
the mRNA molecule attaches to a ribosome
What do tRNA molecules have
triplet of unpaired bases at one end, known as the anticodon, and a region at the other end where a specific amino acid can attach
What happens after mRNA molecule attaches to ribosomes
The tRNA molecules bind with their specific amino acids and bring them to the mRNA molecule on the ribosome
How many tRNA can fit on ribosomes
Two tRNA molecules fit onto the ribosome at any one time, bringing the amino acid they are each carrying side by side
