Summary A-Level Biology- Protein Synthesis

Protein
Synthesis
Gene -


sequence of nucleotides molecule thatencodes a
on a DNA

protein.
Allele-variation of a
gene.
The genetic code of a gene is the sequence of bases in theDNA
molecule that
codes for the order of amino acids in a polypeptide.

Genetic Code Features: codon
- -
Triplet code-sequence of 3 basel codel for one amino acid
only one codon codes for one amino acid.
Universal -
the same triplet codes same amino acid
for the in
all organisms.
Non-overlapping-codons are read individually and in sequence. In 3's.
Degenerate mostamino acids are coded forby more them
-
one
codon. Also a and stop
START codon.

several codons can be used to make one amino acid.


DNA
allocontains some sequences of bases which do notcode for
anything.
noncoding DNA
-




Non coding base sequences are called introns butthere
are
omitted in the code outthe nucleus.
mRNAwhich takes the

80% of DNA
is
non-coding.
KNA->transcription -> mRNA translation -> protein.
-




too big to leave
nucleus
sequence of triplets
in DNA
gene copied
Single sevenitcodone amino acide
as sequence
of color molecule translated
in
mRNA
which
into
of
to form the protein
leaves the sequence
amino acids
nuceus
I
attaches to
ribosome