blood group A has A antigens on the red blood cells with anti-B antibodies in the plasma. blood group B has B antigens with anti-A antibodies in the plasma. blood group O has no antigens, but both anti-A and anti-B antibodies in the plasma. blood group AB has both A and B antigens, but no antibodies.
Length: 1  A polypeptide is a single linear chain of many amino acids, held together by amide bonds. 2  A protein is one or more polypeptide (more than about 50 amino acids long). 3  An oligopeptide consists of only a few amino acids (between two and twenty).onribosomal peptides are assembled by enzymes that are specific to each peptide, rather than by the ribosome. The most common non-ribosomal peptide is glutathione, which is a component of the antioxidant defenses of most aerobic organisms.
Of some of the polypeptides (proteins) some are enzymes. Enzymes catalyse reactions. Their poltpeptide shape--tertiary structure enables them to do this, as they have an active site which binds to the substrate.