Lecture III - Genetic Code and Translation Flashcards
What is the one gene one protein hypothesis?
Genes function by encoding enzymes, and each gene encodes a separate enzyme.
What is some evidence to support the one gene, one protein hypothesis?
The structure and function of proteins
Beadle and Tatum experiment
Proteins have remarkably diverse biologic functions
Amino Acids are joined together by peptide bonds 6
What is a degenerate code?
Amino acid may be specified by more than one codon.
What are synonymous codons
Codons that specify the same amino acid
What are isoaccepting tRNAs?
different tRNAs that accept the same amino acid but have different anticodons
What is the wobble hypothesis?
Wobble may exist in the pairing of a codon and anticodon. Meaning pairing rules are relaxed at the third position. Ie) G could pair with C or U.
Through wobble, a single _______ can pair with more than one ______?
anticodon; codon.
What is a reading frame?
three ways in which the sequence can be read in groups of three. Each different way of reading encodes a different amino acid sequence.
What is Nonoverlapping?
A single nucleotide may not be included in more than one codon.
What is The universality of the code?
Near universal, with some exceptions.
Translation of an mRNA molecule takes place where?
Ribosome
There are exactly __ different aminoacyl-tRNA syntheses in a cell.
20
An amino acid attaches to the 3’ end of a? How is specificity established?
tRNA; positions on the tRNA are recognized by appropriate aminoacyl-tRNA synthetase
What initiates translation?
IF-3 & initiator tRNA with N-formylmethionine attached to form fmet-tRNA.
Poly A tail also plays a role
GTP is the energy molecule
The Kozak sequence does what in eukaryotic cells?
facilitates the identification of the start codon. Consensus sequence
