dna and protein synthesis Flashcards
universal
the genetic molecule in all living organisms
eg. GGT codes for glycerine in all living organisms
non-over lapping
each DNA triplet and gene is separate form each other
degenerate
the same amino acid can be coded for by the more than one triplet
genome
the complete set of genes in a cell
proteome
the full range of proteins that a cell can make
two steps of protein synthesis
transcription: where DNA scribed to be mRNA
translation: where mRNA translates for amino acids
gene
a sequence of DNA that codes for a polypeptide or a functional RNA
locus
the location of a gene on a chromosome
dna triplet
a sequence of 3 dna bases that code for a specific amino acid
introns
regions within a gene that doesn’t code for polypeptides
formation of mRNA (transcription)
DNA strands are separated by breaking h bonds
Only template strand is used to make mRNA
Complementary base pairing occurs
Adjacent RNA nucleotides joined by RNA polymerase
Pre-mRNA formed
Splicing occurs to form mRNA
Prokaryotes don’t have splicing
after mRNA in cytoplasm, what happens? (translation)
mRNA associates with a ribosome
Ribosome finds start codon
tRNA carries a specific amino acid
Anticodon joins to codon
Ribosome moves along to next codon
Process repeated and amino acids joined by peptides bonds
Ribosome detaches
role of tRNA
tRNA anticodon complementary to codon
tRNA brings specific amino acid
Amino acids are carried, transported to ribosomes
Allows for correct sequence of amino acids along polypeptide
comparing DNA to RNA
dna: contains deoxyribose and thymine, and is longer
rna: contains ribose and uracil, and is shorter
comparing DNA to mRNA
same differences as dna to rna (3 points ) AND
dna: has base pairing and contains introns
rna: doesn’t have either of these
tRNA
a polynucleotide, folded by some h bonds, and anticodon is specific to the amino acid that it carries
x is where AA attaches
y is the anticodon
