Protein Synthesis Flashcards
What is the process of making and controlling a genes characteristics called
Gene expressions
Gene expressions
Transcription
Translation
What are the 3 types of RNA
mRNA
tRNA
rRNA
What does mRNA do
It carries genetic messages that code for that codes for a particular protein from the nucleus to the cytoplasm
mRNA characteristics
Single stranded
Contains one gene
Short lifetime
Why does mRNA have a short lifetime?
So that it doesn’t continuously produce a specific protein.
The protein only exists for the time you need it for
tRNA characteristics
-About 80 nucleotides long
-folds up into complementary base pairings
-forms a looped clover leaf structure
Where does the amino acid bind on a tRNA
At the end of the molecule where the base sequence is always AAC
What is on the middle loop of a tRNA
There is a triplet nucleotide sequence called an anticodon
How many tRNA molecules are there
64 different tRNA molecules with 64 different anticodon sequences which are complementary to 64 codons
How do amino acids attach to the tRNA
Aminoacyl tRNA synthase (an enzyme)
What does transcription do in prokaryotes
It directly produces mRNA from DNA
What does transcription do in eukaryotes
It results in the production of pre-mRNA which is then spliced to form mRNA
What does tRNA stand for
Transfer RNA
What.does rRNA stand for
Ribosomal RNA
rRNA is forms
rRNA + proteins form ribosomes which are the site of mRNA translation and protein synthesis
Where does transcription take place
Nucleus
What’s at the start of each gene
A promoter (base sequence)
First step in transcription
The promoter attaches to the promoter region and the H bonds are broken
2nd step of transcription
-The DNA antisense strand is used as a template for the mRNA sense strand via the use of complementary base pairings they create a strand of mRNA
3rd step of transcription
The new nucleotides are joined together by phosphodiester bonds via the use of RNA polymerase enzyme
4th step
The primary strand of mRNA is called pre-mRNA which is an exact copy of the gene including introns which have to be spliced out
5th step
The post transcriptional modifications are now complete, this is now mature mRNA
What is translation
The conversion of a genetic message into an amino acid sequence
Step 1 of translation
A ribosome attached to the mRNA using an invitation codon
