Ls3-Ch15 Genetic Code

Front 1

01: what is one property of the AA code?

Back 1

DEGENERACY: several codons can each code for one shared amino acid.

SYNONYMS: codons for the same AA. will have similar tRNAs

Front 2

02: which directions are codons and anticodons read?

Back 2

CODON: 5'->3'

ANTICODON: 3'->5'

Front 3

03: What is "wobble"

Back 3

anticodon base can pair w/ alternate bases in codon, especially variation in THIRD base of the codon.

ie U at the wobble position can pair with an A or G in the third base of the mRNA

one tRNA recognizes all codons for one AA

Front 4

04: how was the RNA-AA code cracked?

Back 4

using 3 base-long sections of RNA, put into conditions w/ ribosome pieces. if incorrect AA, ribosome complex will not form.

then add all tRNA's to ensure a complex will form. make sure one tRNA is hot.

if complex forms (as seen on filter paper over a vacuum that sucks ) filter will be radioactive, and has your tRNA in there. ( free tRNA will pass through while ribosomes stick)

Front 5

05: rules of the genetic code

Back 5

1: codons read 5'->3'
2: codons do not overlap or form gaps
3: the reading frame is fixed

Front 6

06: kinds of point mutations

Back 6

supressor: stop mutations (make an incomplete chain)

intergenic (no effect)

MISSENSE: changes one codon to another putting in wrong AA

FRAMESHIFT: add 1 or 2 bases, drastically altering protein

Front 7

07: is the genetic code universal?

Back 7

mostly.

some AA's were expanded, new stop codons added.