Cellular Processes and structure Energy and Matter Free energy Macromolecules Interactions between molecules Photosynthesis Cellular respiration Cycles of matter
Interactions between molecules AP Framework: 4.B.1 Holtzclaw: 73-75 (Ch8.3) Campbell: (Ch8.4)
Enzymes are proteins Act as catalysts Naming convention: substrate+ase ex. lactase Exception: some RNA molecules act as enzymes
Enzymes are Catalysts Increase rate of the reaction by lowering EA Not changed by the reaction
Enzyme action Orient reactants to each other increase chances of proper collision The molecule they act on is called a substrate Can combine or break down molecules
Enzyme action (cont) Induced fit model substrate binds to active site on enzyme active site is shaped specifically Enzyme changes shape catalyzing the reaction
Cofactors / Coenzymes Many enzymes require other molecules to work Coenzymes: organic molecules (vitamins) Ex. Niacin (B3) required to make NAD Cofactors: inorganic molecules (minerals) Ex. Iron required to make hemoglobin
Competitive Inhibition Inhibitor prevents binding of substrate
Allosteric inhibition causes a conformational change in the enzyme which prevents binding of the substrate
Allosteric Interactions allow for feedback inhibition of metabolism Ex. ATP inhibits the activity of phosphofructokinase.
Environmental Influences on Enzyme Function The local environment can affect the shape of the enzyme, which will affect its function. Ex. Temperature and pH.
Concentration and Enzyme Function The concentration of enzyme and substrate will also affect enzyme function.
Measuring Enzyme Activity Enzyme Activity can be measured in different ways: Appearance of a product Disappearance of a substrate Indirect Analogs: Ex. Color Change, Change in Temp.
Variation in molecular units provides cells with a wider range of functions
Variation in molecular units provides cells with a wider range of functions
Variation in molecular units provides cells with a wider range of functions
Be Able To 4.17 Analyze data to identify how molecular interactions affect structure and function