Enzyme Function

Ectothermic and Endothermic Organisms

  • Endotherms are animals that maintain constant body temperatures that are usually higher than their surroundings. Endotherms generate considerable amounts of heat, have insulating structures (e.g. feathers, fur and fat layers), and use about 5 times more energy than ectotherms. The metabolic demands of endothermic animals are much higher than that of ectothermic animals. Examples of endotherms are mammals and birds.

Energy in Cells

Adenosine
Triphosphate
ArrowAdenosine
Diphosphate
+Phosphate
Group
ATPArrowADP+H2PO4–

The Action of Enzymes

REACTANTSArrowPRODUCTS
REACTANTSCatalystsPRODUCTS
Arrow
  1. Lock and Key Model - Substrate molecules already have the right shape to fit an enzyme.
  2. Induced Fit Model - Interaction between the enzyme and the substrate induces or changes the shape of the molecules to produce a suitable fit.

Factors Affecting Enzyme Activity