gene expression 1.3 Flashcards
what is gene expression
the process of activating specific genes to produce a required protein
what are the two steps in gene expression
transcrioptin
translation
genes are expressed to produce what
proteins
are all genes in a cell expressed
no only a fraction are
what types of rna does transcription and translation involve
mRNA
tRNA
rRNA
how many strands does RNA have
one
what is rna composed of
ribose sugar
phosphate
a base
what are the four bases of rna
cytosine
guanine
adenine
uracil
what does messanger rna do
carries a copy of dna code from the nucleus to the ribosome
mrna is …. in the nucleus and …. into proteins by ribosomes in the ….
transcribed
translated
cytoplasm
what is each triplet of bases in the ribosome called and what does it code for
codon
amino acid
what does trna do
carries a specific complimentary amino acid to the ribosome
what does rrna do
form the ribosomes with proteins
what does a trna molecule have
a triplet of bases called anticodons at one end and an attachment site for amino acids at another
whats the role of rna polimerase in transcription
unwinds the double helix and breaks hydrogen bonds between bases
what does rna polymerase synthesise
a primary transcript of mrna from rna nucleotides by complimentary base pairing
what is uracil complimentary to
adenine
what are the non coding and coding regions called
non coding introns
coding exons
what are cut out from the primary transcript
introns
what regions are joined together to form the marure transcript
exons
is the order of exons changed during splicing
no
what does fna splicing form
mature mrna transcript
trna translates mrna into what at the ribosome
polypeptide
what bonds join together the amino acids to form what
peptide bonds to form polypeptide
