Slides in this set
Characteristic of Genetic Code
· Three bases make a codon that
code for an amino acid.
· It is non-overlapping which
associates with how we read the
code. Each codon stands alone and
doesn't share it's bases with another
triplet. This is due to there being
more than one codon to an amino
· It is degenerate ; contains more
information than is needed. This can
mean that there is more than one
codon to an amino acid like tyrosine-…read more
-As DNA is too large a molecule to move out of the nucleus
mRNA (messenger...) transcribed the relevant information
and transports this into the cytoplasm to the ribosomes and
-Hydrogen bonds are broken between the base in the DNA
by RNA polymerase.
-5' prime strand is copied to give a single strand of mRNA
using free RNA nucleotides.
-The newly synthesized strand moves through the nuclear
pores in the membrane, carrying the message, via the ER, to
the ribosomes. New RNA strand is the
DNA is the template Uracil replaces sense strand while
strand Thymine in RNA DNA is the anti-sense
- tRNA (transfer), mRNA and rRNA (ribosomal) are
involved in this process.
- mRNA attaches to a ribosome and it is read from
the start codon- Methionine.
- tRNA aligns itself adjacent to it's complementary
codon in mRNA.
- Hydrogen bonds form between the anti-codon and
codon holding it in place while the enzymes link the
amino acids together by peptide bonds.
- tRNA returns to the cytoplasm to pick up another
amino acid and the ribosome moves along,
revealing a polypeptide chain when it has reached
the termination codon.
- Multiple ribosomes- polysome.…read more
tRNA and rRNA
- tRNA has a unit of three
bases at one end and an
amino acid which is
specific to the molecule.
- It is clover leaf shaped.
- rRNA is made in the
nucleus and moves out
into the cytoplasm to
bind with proteins
forming ribosomes.…read more