6. Respiration Flashcards
Can energy be created
Energy cannot be created or destroyed, and exists in a number of forms
Name the 8 forms of energy
Potential, kinetic, heat, electrical, light, sound, chemical, atomic
What do all cells need
Energy, life cannot be sustained without energy
What is the source of energy
The sun is the source of energy in all living things
How can food be discovered to have energy
If we burn food its energy is released as heat, like fuel
All food contains energy
What is a more effective way of finding if food contains energy
By using a calorimeter, increased surface area on the coiled copper wire, heatproof platform keeps heat in, stirrer disperses heated water
Which contains more energy, carbohydrates, protein or lipids (fat)
LIPID - 32kj/g
Protein - 17kj/g
Carbohydrate - 16kj/g
How can energy be released
Respiration
What is the breakdown of glucose with oxygen present called
Aerobic respiration
Explain the dry mass experiment
Peas in vacuum flask, temps recorded at start and after being left for a few days
What does a respirometer do
A respirometer measures the rate at which an organism respired
How does a respirometer work
Liquid is sucked up tube by disappearance of oxygen
Rate water moves = rate of respiration
What do respiring organisms produce
Water and carbon dioxide
What is ATP
Vitally important, as it is a source of immediate energy
which all cells can access
How are the three Phosphates joined
By high energy bonds, which store the energy
What is the ATP equation
ADP + P(i) + energy ATP
What are the roles of ATP
To store and release energy
To provide a link between energy releasing reactions and energy consuming reactions
What is aerobic respiration
Takes place in all cells and is essential to life
Series of enzyme controlled reactions released in a controlled fashion
Glucose + Oxygen > Carbon dioxide + Water + Energy
Describe glycolysis
Breakdown of glucose in the cytoplasm
Anaerobic
Breaks down to 2x pyruvate and 2 ATP are produced
Describe aerobic stage
Further breakdown of glucose in mitochondrion
Oxygen required
Kreb’s cycle - as pyruvate goes into cycle and through it, it loses 3x carbon dioxide
Breaks down to 2x 18 (36) ATP, carbon dioxide, and water
What is the total ATP production
Glycolysis = 2 ATP
Aerobic stage = 36 ATP
TOTAL = 38 ATP
Describe fermentation
Less efficient, produces toxic waste
Animal - In cytoplasm, anaerobic, 2 ATP produced
- Pyruvate > Lactate
- Reversible process, when oxygen is available
- Oxygen debt, repaid by rapid breathing
Plant - In cytoplasm, anaerobic, 2 ATP produced
- Pyruvate > Ethanol + carbon dioxide
- Irreversible process
- Carbon dioxide is given off leaving only 2, when pyruvate needs 3
