Archives: Questions and Answers

Describe that the progress of enzyme-catalysed reactions can be followed by measuring the concentrations of reactants and products

Explain the specificity of enzymes in terms of the complementary shape and fit of the active site with the substrate (‘lock and key’ hypothesis)

Explain enzyme action with reference to the substrate, active site, enzyme-substrate complex, and product

Describe enzymes as proteins that function as biological catalysts and are involved in all metabolic reactions

Describe a catalyst as a substance that increases the rate of a chemical reaction and is not changed by the reaction

Describe and be able to do chemical tests for: (a) starch (iodine solution) (b) glucose and maltose (Benedict’s solution) (c) protein (biuret test) (d) lipids (ethanol emulsion test)

State that large molecules are made from smaller molecules, limited to: starch, cellulose and glycogen from glucose; proteins from amino acids; lipids from fatty acids and glycerol; DNA from nucleotides

Explain the importance of active transport in ion uptake by root hair cells

Describe active transport as the movement of molecules or ions into or out of a cell through the cell membrane, from a region of their lower concentration to a region of their higher concentration (i.e. against a concentration gradient), using energy released during respiration

Investigate osmosis using materials such as dialysis tubing