Answer:
Glycogen synthase is phosphorylated at only one site.
Explanation:
Glycogen synthase has multiple sites where phosphorylation can occur. Glycogen synthase may have 9 or more sites where it can be phosphorylated as a result of which it's activity is down regulated. It simply means that the regulation of this enzyme does not occur through binary on/off switching, in fact it's activity is modulated over a wide range in response to various signals.
In contrast to glycogen phosphorylase which gets activated when it is phosphorylated at it's serine residues, glycogen synthase gets inactivated by phosphorylation.
As soon as another enzyme GSK3β phosphorylates glycogen synthase, it gets inactivated as a result of which glycogen synthesis halts in the liver.
Answer:
) Presence of specific glycoproteins on the cell membrane
Explanation:
When specif glycoproteins(antigens) or antibody are present on a cell membrane of Red blood cell,they can be used to identify the blood type.Antigens are substances capable of triggering an immune response in a cells.
In addition,they function in transport of molecules across the RBC. They help in the maintenance of the RBC,and aiding the arrest of cells capable of causing diseases to the body.
Therefore,they are good determinants of blood types,based on this two types of antigens present in a blood type.
These two antigens used for classification of blood types are the 1-the ABO antigens 2,the Rhesus antigens.
Essentially,when a WBC produces an antibody ,which is a molecule that defends the body,If this is not compatible,the antibody will recognize it as a foreign body and attack it.Thus such blood types are not compatible. Thus the antibody-antigen reaction are good for knowing and classify blood types.
Antigen can also be glycoprotein,carbohydrate or glycolipids.
Generally blood types are inherited from both parents.Therefore the antigen present on the RBC are combination of the alleles from each parent.
