topic 5 photosynthesis/resp/energy transfer Flashcards
Explain why the student marked origin using pencil than using ink in chromatography{1}
I.nk and (leaf) pigments would mix
. w ink origin/line in different position
. w pencil origin/line in same position
. with pencil origin/line still visible
The pigments in leaves are different colours. Suggest & explain the
advantage of having different coloured pigments in leaves {1}
. absorb different/more wavelengths of light for photosynthesis
Where precisely is rubisco found in a cell? {1}
. stroma
Atrazine binds to proteins in electron transfer chain, reducing transfer of electrons down the chain.
Explain how this reduce rate of photosynthesis in weeds {4]
. reduced transfer of protons across thylakoid membrane
. less ATP produced
. less reduced NADPH produced
.light-independent reaction slows
Crops use light energy to produce photosynthetic products.
Describe how crop plants use light energy during the LDR {5}
.excites electrons to leave chlorophyll
. electrons move along electron transfer chain releasing energy
. energy used to join ADP and Pi to form ATP;
. photolysis of water produces protons, electrons and oxygen
. NADP reduced by electrons and H
what are the products of photolysis used for
. H ions- move from thylakoid into ATP synthase to reduce NADP
. electrons- replace electrons in chlophyll
. oxygen- waste gas or used for respirtaion
Malonate inhibits a reaction in the Krebs cycle.
Explain why malonate would decrease the uptake of oxygen in a respiring cell. {2}
. no NADH and FADH
OR
no hydrogens/electrons removed and passed to etc
. oxygen is the final electron acceptor;
Explain why converting pyruvate to lactate allows the continued production of ATP by anaerobic respiration. {2}
.Regenerates NAD
. so glycolysis continues;
Suggest one reason why it was important that the student left the
apparatus for 1 hr after the yeast culture reached a constant
temp{1}
. make sure oxygen was used up
why is a log scale used to count number of cells {1}
. large diff/range between numbers
Many yeast cells die during the death phase . Suggest 1 reason why{1}
.Decrease/no glucose/substrate
OR
Increase in ethanol/carbon dioxide/acidity
For 1st 10 mins, the tap attached to tube A was left open and the syringe from tube B was removed.
Suggest three reasons why the apparatus was left for 10 minutes {3}
. reach equilibrium
.allow respiration rate to stabilise
.allow pressure change
Describe the advantage of the Bohr effect during intense exercise.
. increases dissociation of oxygen
. for aerobic respiration at the tissues/muscles/cells
OR
Anaerobic respiration delayed at the tissues/muscles/cells
OR
Less lactate at the tissues/muscles/cells;
what are 2 benefits of an etc rather than a single electron {2}
. energy released gradually
. less energy released as heat
name 2 alternatives that can be used as respiratory substitutes {2}
. amino acids from protiens
.glycerol & fatty acids from lipids
Suggest what the scientist should do to ensure that he has removed all the water from the sample {2}
.weigh and heat
. until constant mass
Suggest one way in which AMF may benefit from their association with
plants. {1}
. glucose/carbohydrate
(carbon containing molecule)
Describe the role of saprobionts in the nitrogen cycle {2}
. enzymes in ammonification to decompose protien/urea/dna/rna
.release ammonium ions
Youre given samples of water from 3 different rivers from eutrophication.
Describe how youd obtain quantitative measurement of their
cloudiness . {3}
.use colorimeter
.to measure transmission of light
. standardise is my using the same wavelength
The scientists used units of μg g–1 for the concentration of ammonia in soil.
Suggest why, in this investigation, the scientists used these units. {2}
.μg- because there is very little amount of ammonia/avoid a lot of decimal
.g-1 - to compare samples
