AP BIOLOGY

Detailed explanation-1: -Phosphorylation is the addition of a phosphoryl (PO3) group to a molecule. In biological systems, this reaction is vital for the cellular storage and transfer of free energy using energy carrier molecules.

Detailed explanation-2: -Phosphorylation regulates protein function and cell signaling by causing conformational changes in the phosphorylated protein. These changes can affect the protein in two ways. First, conformational changes regulate the catalytic activity of the protein.

Detailed explanation-3: -Phosphorylation allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter. Phosphorylation of glucose is a key reaction in sugar metabolism.

Detailed explanation-4: -Protein phosphorylation is defined as a covalent addition of the phosphate group to the side chain of tyrosine, serine, and threonine amino acid residues.

Detailed explanation-5: -Phosphorylation is a reversible reaction; it means that a phosphate molecule can be added and removed. The enzymes that are responsible for adding phosphate groups to proteins are known as “kinases”. Those involved in the removal of these phosphate groups are called “phosphatases”.