BIO 211 April 24th 17B/ch 16

bio 211 final

what are the key players in translation

what are the key players in translation

mRNA, tRNA, amino acids, ribosomes

what is the structure of tRNA

anticodon and amino acid binding site makes a a distinctive folded structure with three hairpin loops that form the shape of a three-leafed clover

mRNA

carries instructions to make proteins (messenger RNA)

wobble hypothesis

the 3rd base in an mRNA codon can undergo non-Watson-Crick base pairing with the 1st base of a tRNA anticodon.

structure of ribosomes

large and small subunits with A,P,E sites

what are the three steps in translation

initiation, elongation, and termination

intiation

the ribosome gets together with the mRNA and the first tRNA so translation can begin.

elongation

the ribosome continues to translate each codon in turn. Each corresponding amino acid is added to the growing chain and linked via a bond called a peptide bond. Elongation continues until all of the codons are read.

termination

One of the three stop codons enters the A site. No tRNA molecules bind to these codons, so the peptide and tRNA in the P site become hydrolysed, therefore releasing the polypeptide into the cytoplasm. The small and large subunits of the ribosome then dissociate, ready for the next round of translation.

ribosomes are the site for

protein synthesis

if the mRNA codon is AUA, what is the anticodon on the tRNA (opposites)

UAU

(A and U go together and T and R or G go together)

knock out mutant

to mutate the DNA in a way that stops the gene's expression permanently.

null mutants

when enzyme gets mutated and fucks up and there is no enzyme made at all or it doesn’t do anything

one gene one enzyme hypothesis

the idea that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway.

one gene one polypeptide hypothesis

The theory that each gene is responsible for the synthesis of a single polypeptide.

central dogma

a theory stating that genetic information flows only in one direction, from DNA, to RNA, to protein, or RNA directly to protein.

triple code

each amino acid is made up of 3 letters. like AUA or GTG

Each genetic code consists of three ribonucleotide letters, thus referred to as a triplet code. As such, a genetic code is a triplet code in which a sequence of three bases is needed to specify one amino acid.

reverse transcriptase

an enzyme used to generate complementary DNA (cDNA) from an RNA template

point mutation

A genetic alteration caused by the substitution of a single nucleotide for another nucleotide.

missense mutation

A genetic alteration in which a single base pair substitution alters the genetic code in a way that produces an amino acid that is different from the usual amino acid at that position.

inversion

A chromosomal defect in which a segment of the chromosome breaks off and reattaches in the reverse direction.