Biology Paper 2 2020

Describe how a phosphodiester bond is formed between two nucleotides within a DNA molecule

-condensation reaction between deoxyribose and phosphate group

-catalysed by DNA Polymerase

Explain how an arterial can reduce blood flow into capillaries

-muscle contracts

-constricts lumen

a competitive inhibitor decreased the rate of reaction of an enzyme controlled reaction

-inhibitor similar shape to Active site

-inhibitor binds to the substrate Active site

-prevents enzyme-substrate

Explain why HIV affects the production of antibodies when AIDS develop in a person

-No antibodies produced

-HIV destroys helper T cells

-B cells are not stimulated

Describe the process involved in the absorption and transport of digested lipid molecules form ileum into lump vessels

-Michelles contain fatty acids and bile salts

-Makes fatty acids soluble in water

-Fatty acids absorbed by diffusion

-Triglycerides reformed in cells

-vesicles move to cell membrane

Describe how the structure of a protein depends on the amino acid it contains

-creates Active site in enzymes

-Primary structure is sequence of amino acids

-Secondary structure is formed by hydrogen bonds between amino acids

-Teritary structure forms interactions between R groups

-Quartenary structure contains more than one polypeptide chain