Energy + Enzymes Flashcards
ATP
Stores energy needed for cell processes as energy can’t be used directly
Cell needs energy
ATP breaks down and energy is released
Aerobic respiration
Plenty of oxygen, 32 ATP, produces CO2 and H2O
Anaerobic respiration
Not enough oxygen, 2 ATP, produces lactic acid
Anaerobic respiration plants
Produces ethanol and CO2 instead of lactic acid
Hydrogen carbonate indicator
Goes orange-yellow in presence of CO2
Respiration of yeast
Depends on temperature, concentration of sugar, water bath and count CO2 bubbles produced
How does yeast make bread?
- Enzymes break down carbohydrates in flour into sugars
- Yeast respires aerobically producing CO2, causes dough to rise
- Ferments (anaerobically respires) when no oxygen left
- CO2 trapped, pockets of gas expand, dough rises
- Baked in oven until yeast dies and alcohol boils away
Enzymes
Biological catalysts that increase speed of a metabolic reaction without being used up
Substrate
Molecule that is changed in a reaction
Active site
Part where substrate joins to enzyme
“Lock and Key” model
Substrate fits perfectly, enzyme remains unchanged after
Effect of temperature
Increases rate initially, more energy, more collisions
Too hot, denatures enzyme by changing shape of active site
Effect of pH
Too high or too low means enzyme denatures, optimum pH usually 7
Temperature effect on enzymes practical
Hydrogen peroxide breakdown using catalase and collecting oxygen
