Respiration Flashcards
Where does the Electron Transfer chain take place in a cell during respiration?
Inner membrane of mitochondria
If there is a shortage of oxygen in muscle cells during exercise, some pyruvate is converted into lactate. Explain why muscles become fatigued when insufficient oxygen is available (2)
- increased concentration of lactate lowers pH
- enzymes are inhibited
How is anaerobic respiration of glucose in yeast different from anaerobic respiration of glucose in a muscle cell (2)
- ethanol formed by yeast
- lactate formed by muscle
- Co2 released by yeast, not in muscle
How is anaerobic respiration of glucose in yeast similar to anaerobic respiration of glucose in a muscle cell (2)
- ATP formed
- pyruvate formed
- glycolysis takes place
Explain why converting pyruvate to ethanol is important in allowing the continued production of ATP in anaerobic respiration (2)
- allows NAD to be recycled
- so that Glycolysis can continue
Explain why oxygen is needed for the production of ATP on the cristae of the mitochondria (3)
- ATP formed as electrons pass along transport chain
- Electrons cannot be passed along the electron transport chain if there’s no O2 to accept them
- forms H20 from reduced NAD
Respiration produces more ATP per molecule of glucose in the presence of oxygen than it does when oxygen is absent. Explain why (2)
- oxygen is the terminal electron acceptor
- oxidative phosphorylation provides most ATP
Why was the solution in which the mitochondria suspended isotonic? (1)
- prevent damage to mitochondria caused by osmosis
Describe the part played by the inner membrane of the mitochondrion in producing ATP (3)
- Electrons transferred down Electron Transport chain
- Provides energy to take protons into intermembrane space
- Energy used to combine ADP and phosphate to produce ATP
Explain the advantages of collecting a large number of results (2)
- allows anomalies to be identified
- allows use of statistical test
Explain why it is important for plants to produce ATP during respiration in addition to during photosynthesis (5)
- In the dark, no ATP production in photosynthesis
- some tissues unable to photosynthesise
- ATP cannot be stored
- Plant uses more ATP than produces in photosynthesis
- ATP needed for active transport
Describe how ATP is made in the mitochondria (6)
- substrate-level phosphorylation
- krebs cycle produces reduced coenzymes
- reduced coenzymes release electrons
- electrons pass through electron transport chain
- energy is released
- combines ADP and Pi to form ATP
Describe how NAD is regenerated in anaerobic respiration in yeast cells (1)
Formed when reduced NAD is used to reduce pyruvate to ethanol
Humans synthesise more than their body mass of ATP each day. Explain why it is necessary for them to synthesise such a large amount of ATP (2)
- ATP cannot be stored
- ATP only releases a small amount of energy at a time
Give two ways in which the properties of ATP make it a suitable source of energy in biological processes (2)
- Involves a single reaction
- soluble
- energy released in small amounts
Some of the lactate is oxidised to pyruvate by muscles when they are well-supplied with oxygen. Suggest an advantage of the lactate being oxidised in the muscles (2)
- Lactate is an energy source
- Muscles have increased ATP supply
Write a simple equation to show how ATP is synthesised from ADP (1)
ADP + Pi –> ATP
Human skeletal muscle can respire both anaerobically and aerobically. Describe what happens to pyruvate in anaerobic conditions and explain why anaerobic respiration is advantageous to human skeletal muscle (4)
- forms lactate
- regenerates NAD
- allows glycolysis to continue
- can still release energy when oxygen is in short supply
Apart from Respiration, give three uses of ATP in a liver cell (3)
- Active Transport
- Protein Synthesis
- Mitosis
Describe how acetyl coenzyme A is formed in the link reaction (2)
- oxidation of pyruvate and carbon dioxide is released
- addition of coenzyme A
The mitochondria in muscles contain many cristae. Explain the advantage of this (2)
- larger S.A. for the electron carrier system
- provides ATP for contraction
Substances which there would be a net movement into the mitochondria
- pyruvate
- ADP + Pi
- reduced NAD
- oxygen
Without oxygen, less ATP is produced by respiration. Explain why (2)
- oxygen is the terminal acceptor
- the electron transfer chain cant work
Where does Glycolysis occur in a cell during respiration (1)
Cytoplasm
