gene expression Flashcards
what is gene expression?
Gene expression is creating proteins by using the code from 1 gene.
describe 3 differences between DNA and RNA
DNA: double stranded, thymine, deoxyribose sugar
mRNA: single stranded, uracil, ribose sugar
what is the function of mRNA?
it carries a complimentary copy of a genes code to a ribosome for translation
what is a triplet of based on an mRNA called?
codon
state 4 things that are required for DNA transcription?
1) template strand
2) free RNA nucleotides
3) RNA polymerase
4) start and stop codon
name stage 2 of gene expression
translation
what term is given to the triplet of bases on a tRNA molecule?
anticodon
where does “splicing” occur?
in the nucleus
where does protein synthesis occur
the ribosome
name the type of bond which binds neighbouring amino acids together.
peptide bonds
what term is given to a chain of amino acids
polypeptide chain
describe how the chain of amino acids are held in their 3 dimensional shape and explain the importance of this shape
they are held together by hydrogen bonds and other interactions
importance=for functioning
why are the order of bases so important?
the order of bases determines the order of aa’s (amino acids) and protein made
name the 3 types of RNA
mRNA, tRNA, rRNA
what is transcription?
when mRNA is made using 1 gene on a DNA strand, mRNA then carries this code from the RNA (in nucleus) to the ribosome (in cytoplasm)
what base (nucleotide) does uracil replace?
adenine
what does the primary transcription (mRNA) contain?
introns and exons
give some info on introns
non coding regions (insignificant), gets removed
give some info on exons
coding region, kept. due to introns being removed, the exons are spliced together.
what happens to the transcription when the introns are removed?
it becomes a mature transcript
give 3 points of alternative RNA splicing
- one gene, many proteins
- different proteins can be expressed from 1 gene as a result of alternative RNA splicing.
- different mature mRNA transcripts are produced depending on which exons are retained.
where does splicing occur
in the nucleus
where does protein synthesis occur
ribosome
