Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
How is a leaf adapted to photosynthesis? |
Large SA to collect usnlight arrangement to minimise overlapping thin so short diffusion distance transparent upper epidermis and cuticle air spaces for diffusion xylem stomata that open when light is intense long narrow upper mesophyll cels packed with chloroplasts |
|
Why is it important that the photolysis of water occurs? |
Chlorophyll continues to absorb light neergy and to reduce NADP |
|
Describe what happens in the LDR |
Light absorbed by chlorophyll molecule; molecule is excited, and pair of electrons in molecule gain energy and leave the molecule; electrons taken up by electron carriers in transport system; in thylakoid membrane; lose energy as electrons transferred; used to make ATP by photophosphorylation; NADP reduced by electrons and hydrogen ions from photolysis of water; |
|
How are chloroplasts adapted to the LDR? |
Thylakoid membranes provide a large surface area for the attachment of proteins/carriers proteins hold chlorophyll in place chloroplast has DNA and ribosomes to manufacture proteins when necessary |
|
Describe what happens in the LIR |
CO2 diffuses into leaf through stomata; combines with RuBP catalysed by Rubisco; 2*GP formed; reduced into TP; using reduced NADP and ATP; TP is a sugar; used to make glucose/triglycerides/phospholipids/proteins; and regenerate RuBP; USING ATP; |
|
How are chloroplasts adapted to the LIR? |
Stroma contain all enzymes needed DNA and ribosomes to manufacture enzymes stroma has grana, so products readily diffuse |
|
In the lollipop experiment, how are the products in methanol separated? |
2-way chromatography |
|
What is the law of limiting factors/how do you identify the limiting factor? |
Factor which is at its least favourable value/in shortest supply increasing increases the rate of photosynthesis |
|
What is the compensation point? |
point at which no net exchange of gases into or out of the plant |
|
Why does temp affect rate of photosynthesis? |
Increases rate of LIR due to enzyme involvement |
|
Why is measuring the volume of oxygen produced by pondweed not reflective of rate of photoysnthesis? How do you overcome this? |
Some oxygen used in respiration/dissolved in water - actually measuring how much photosynthesis exceeds respiration; measure rate of oxygen taken up in dark |
|
How can you control CO2 conc + temp + water |
Burn fossil fuel heater spray/irrigate |
|
What does anaerobic resp produce? |
Ethanol and CO2 in plants and yeast lactate in animals |
|
Describe the process of glycolysis. |
Hexose sugar split into pyruvate; activation of glucose by phosphorylation - addition of 2 phosphate molecuels makes it more reactive and lowers activation energy; splitting into triose phosphate; TP oxidised to produce 2*NADH 2*ATP produced per TP into pyruvate |
|
Where does glycolysis occur? |
The cytoplasm of cell |
|
What is the overall yield from glycolysis? |
2 ATP, 2 NADH, 2 pyruvate |
|
Describe what happens in the link reaction |
Pyruvate actively transported into matrix of mitochondria; it is oxidised into CO2 and acetate/ethanoic acid producing one NADH combines with acetylcoA to be used in Krebs/be right shape for enzyme |
|
Describe what happens in the Krebs cycle |
AcetylcoA combines with 4C molecule to form citric acid; undergoes oxidative, decarboxylation, losing 2 CO2 molecules and reducing 3 NAD and 1 FAD; ATP produced by substrate-level phosphorylation; 4C regenerated |
|
What is the importance of the Krebs cycle? |
Breaks macromolecules into smaller ones ; source of intermediates, fatty acids and amino acids; produced reduced coenzymes with potential to produce ATP; regenerates 4C to prevent acetylcoA from accumulating |
|
What is a coenzyme? |
A molecule required for the function of particular enxzymes - carry hydrogens and electrons |
|
How does NAD oxidise stuff? |
Acts as coenzyme with dehydrogenase enzymes to remove hydrogen ions and electrons |
|
What is the importance of the Krebs cycle? |
Source of intermdiates - amino acids, faty acids breaks down macromolecuels (acetate into CO2) produces reduced coenzymes with potential to make ATP regenerates 4C compound and prevents acetylcoA from accumulating |
|
Describe what happens in the electron transport chain? |
Reduced NAD and reduced FAD donate electrons to electron carriers in cristae of mitochondria electrons passed through chain via redox reactions lose energy used to pump H+ ions into inter-membranal space H+ions diffuse down gradient into matrix, passing through ATPase Electrons and hydrogen ions combine with oxygen, terminal electron acceptor |
|
How does cyanide = death? |
non-competitively Inhibits enzyme that combines oxygen electrons and hydrogen ions, so 'backs up' chain |
|
What happens to lactate if oxygen is available again? |
Oxidised into pyruvate oxidised further to release energy or converted into glycogen by liver cells |
|
What is the advantage of anaerobic respiration? |
overcome temp shortage of oxygne regenerate NAD to allow glycolysis to continue |
|
what are the differences between aerobic and anaerobic resp? |
Aerobic is slower produced more ATP does not produce lactate takes place in mitochondria |
|
Why do muscle cells carry out anaerobic resp? |
Use up oxygen faster than supplied |
|
Which plant cells carry out anaerobic resp? |
Root hair cells in waterlogged soils |