Post-translation modification

Cards (11)

what determines the primary structure of a polypeptide?
the base sequence of a gene
what are some of the functions of proteins in living organisms?
enzymes
antibodies
hormones
transport proteins
forming structures
where are polypeptides made on ribosomes transported through?
they are transported through the cytoplasm to the golgi body
what does the primary structure of a polypeptide do?
occasionally its functional, but usually its folded into secondary, tertiary or quaternary structures in the ER and, in the golgi body, it may be chemically modified as well
what is the modification of a polypeptide called?
post-transitional modification
what is ’post-transitional modification’?
the modification of a polypeptide
how can polypeptides be chemically modified?
by combination with non-proteins
what are some examples of non-proteins that polypeptides can be chemically modified in combination with?
carbohydrates, making glycoproteins
lipids, making lipoproteins
phosphates, making phospho-proteins
what is an example of a highly modified molecule?
haemoglobin
what is the structure of haemoglobin?
each polypeptide has a-helix regions (secondary structure ) and is folded (tertiary structure)
4 polypeptides are combined (quaternary structure)
in addition, the protein is modified by combination with 4 non-protein haem groups to make the functional molecule
how are polypeptides produced from translation modified?
they may be modified chemically and modified by folding