Respiration Flashcards
The roles of the coenzymes and carrier proteins in the synthesis of atp (4)
reduced nad, h+ions or, and electrons transferred in a series of redox reactions. energy is made available as electrons passed on, energy used to synthesise atp from adp and phosphate. protons passed into intermembrane space
atp is formed in the mitochondria by (6)
substrate level phosphorylation, the krebs cycle produces reduced coenzymes and electrons are released from these reduced co enzymes and pass along the etc. releases energy. allows protons to enter the intermembrane space, protons re enter the matrix via atp synthase, along the proton gradient. atp forms from adp+pi and oxygen is the final electron acceptor.
the enzyme that catalyses isocitrate to a-ketaglutorate is (2)
dehydrogenase, a h+ is removed from isocitrate
suggest how you could determine the dry mass of a sample of plant material
ibtain a sample of plant material and heat to remove water. ensure its below 100 degrees to ensure it doesnt combust, re measure its mass at regular intervals until the mass is constant.
advantage of using dry not fresh mass
as diff plants have diff water contents so this woudl change the mass ratio formed
suggest how a student could investigate the effects of a named variable on the rate of resp of a single celled organism
use a respirometer and use a dye as the terminal electron acceptor for the etc
what is the purpose of the sodium hydroxide solution in a resp set up to measure the rate of aerobic resp
absorbs co2 so that there is a net decrease in pressure as 02 is consumed
Explain why converting pyruvate to lactate allows the continued production of
ATP during anaerobic respiration.
it allows the co enzyme reduced nad to be re oxidised to ensure that glycolysis can continue.
Explain the line between P and Q
No aerobic respiration
- (Because) no (respiratory) substrate
Explain the line between Q and R.
(Oxygen concentration falls because)
1. Aerobic respiration ( have to say aerobic) uses oxygen
- Oxygen is terminal / electron acceptor
For the first 10 minutes, 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.
Equilibrium reached.
Allow for expansion / pressure change in apparatus;
Allow respiration rate of seeds to stabilise.
Suggest and explain why the chosen temperature was 20 °C for this experiment.
Optimum temperature for normal growth of seeds;
2. (Optimum temperature) for enzymes involved in respiration.
Suggest why the rate of gas production decreased between 50 and 60
minutes.
GLUCOSe decreases
) Yeast can also respire aerobically. The student repeated the investigation with
a fresh sample of yeast in glucose solution, but without the oil. All other
conditions remained the same.
Explain what would happen to the volume of gas in the syringe if the yeast
were only respiring aerobically.
(Stays the) same level
2. Same volume of oxygen uptake and carbon dioxide
release;
why does inhibiting the proton gradient mean that more heat was produced and why does this mean that the uptake of oxygen remained constant.
heat released from electron transort chain energy not used to produce atp so released as heat. oxygen used as final electron acceptor.
explain the advantages of collecting a large number of results
increases reliability of averages and can identify anomalies.
name 2 substances formed from pyruvate
co2, water, atp etc
describe how acetyl coa is formed in the link reac
oxidation of pyruvate AND co2 is released, addition of coa
ocalocetae is the first substrate to bind to blah blah explain how it binds
change in shape of active site, moulds around enzyme. complementary to substrate
suggest how the production of succinyl coa could control the rate of reac catalysed by citrate synthase
compeitive inhibitor, prevenets escs forming
the structure of malanoate is very similar to succinate. the scientists added malonate and the resp substrate pyruvate to a suspension of isolated mitochondria. explain why the scientist did not use glucose as the resp substrate for these isolated mitochondria
glucose is used during glycolysis, it cannot cross mitochondrial membranes
explain how malonate inhibits the formation of fumarate from succinate
competitive inhibitor, prevents escs forming
the scientist measured the uptake of oxygen by the mitochondria during the investigation. the uptake of oxygen decreased when malonate was added, why
krebs cycle inhibited as nad not reduced, hydrogens not passed to etc so oxygen cannot be used as the final electron acceptor.
suggesr one explanation for the higher glycerol and fatty acid concentrations in the blood plasma of the athletes after they were given caffeine
breakdown of fats;
at increased rate
explain why the rq for glucose is 1
idea that volumes of oxygen and carbon dioxide the same;
explain- glycogen+caffeine
glycogen is a carbohydrate / broken down to glucose, linked to RQ;
with no caffeine, RQ nearer 1.0 / less carbon dioxide exhaled and
more oxygen inhaled (or vice versa) / with caffeine higher proportion of fats / fatty acids respired;
increased time to exhaustion suggests slower use of glycogen
explain the purpose of the strip of filter paper in the koh solution
to increase surface area (for carbon dioxide absorption);
the level of liquid in the rhs of the mnaometer went down during the exp, why
oxygen is used
so decrease in volume
one sim and one diff between the pattern of mean o2 uptkae by the snails in moist air and those in seawater
taking into account SD e.g. between 5 and 15 °C
both show little effect of temperature
explain why valid conclusions cannot be drawn about trends in o2 concs at temp 25 and above
standard deviations high;
means unreliable
explain why a layer of oil is required in this invest
to prevent o2 entering
suggest why the rate of gas production decreased between 50 and 60 mins
glucose decreases
what would happen to the volume of gas in the syringe if the yeast were only respiring anaerobically
(Stays the) same
2. Same volume of oxygen uptake and carbon dioxide release;
explain why atp is produced more in presscence of o2
Oxygen is final / (electron) acceptor
2. Oxidative phosphorylation / electron transport chain provides (most) ATP / only glycolysis occurs without oxygen
both exps were done at the same temp, why- what does this affect
affects enzymes; Affects respiration;
the level of coloured liquid in the rhs of the manotube went down during exp 1- why
Oxygen taken up
- Carbon dioxide (given out is absorbed by solution
- Decrease in volume
the student repeated exp ones on anaerobic seeds, what happens to level of coloured liquid
Remains the same;
2. No oxygen uptake /
the student closed the tap. after 30 mins the drop had moved to the left, why
Oxygen taken up / used (by woodlouse);
- Carbon dioxide (given out) is absorbed by solution / potassium hydroxide;
- Decrease / change in pressure;
what measurements should the student have taken to calculate the rate of anaerobic resp in a woodlouse
Distance (drop moves) and time;
- Mass of woodlouse;
- Diameter
explain how dnp caused these changes
Less protons,
- Heat released from electron transport / redox reactions / energy not used to produce ATP is released as heat;
- Oxygen used as final electron acceptor
what does it mean by rq=1
aerobic resp same amount of o2 and co2
if different then it must be anaerobic resp as not same amount of o2 and co2
why is the shade plant better adapted at surviving in lower light intensities
as there are lower respiratory losses, less co2 released at 0 light therefore they havea greater npp
explain what would happen to the volume of gas in the syringe if the yeast were respiring aerobically
stay the same as same amount of o2 uptake and co2 release
describe the part played by the inner membrane of a mitochondria in producing atp
electrons transferred down etc
provides energy to take protons
energy used to combine adp and pi to form atp
one thing to remember in respiration questions,
eg
explain why the coloured liquid moved to the right
nad being re oxidised and
having to state whether its aerobic or anaerobic always spot this and write it
FOR THIs question, the yeast cells had been left for an hour therefore all the oxygen would have been used up, you would have needed to spot this so you can write anaerobic respiration.
for a question ab coloured liquid, its always due to a pressure increase in the flask you just need to determine what causes this increase is due to, in this case because its anaerobic respiration the yeast will produce co2 therefore the volume of the flask will increase.
if the volume of the flask increases the pressure will increase so the bubble will move to the right.
and you also needed to mention anaerobic resp. (anaerobic resp produces co2)
if the bubble was more to the right it meant that more anerobic resp occured.
many yeast cells die in the death phase- suggest 2 reasons why
due to the lack of glucose-In addition to oxygen, they require a basic substrate such as sugar.
ethanol conc increasing
dcpip explained
dcpip is reduced by gaining electrons, gains it from photolysis so from chlorophyll as chloroplasts get excited. dcpip gains an electron rather than the electrons going down the etc, tehrefore dcpip is reduced rather than the first protein in the etc being reduced.
explain how chemicals which inhibit the decolourisation of dcpip could slow the growth of weeds
because decolourisation means that it isnt reduced which means that the rate of psynth falls, so you need to explain this
bc the decolourisation falls, psynth falls therefore no atp or nadph would be produced meaning the ldr cannot occur.
dnp inhbits respiration by preventing a proton gradient, how did less atp produced, more heat produced, the uptake of oxygen remained constant
preventing a proton gradienet from being established less atp
heat created from the etc
oxygen is the terminal electron acceptor
name two molecules that could be used as alternative respiratory substrates
amino acids from proteins
glycerol and fatty acids from lipids
how can lipids act as alternative respiritatory substrates
Lipid--> glycerol + fatty acids phosphorylation of glycerol -> tp fatty acid--> acetate acetate enters the link reaction protons produced for oxidative phosphorylation
how amino acids can
deamination produces 3c compounds produce pyruvate for link, 4c/5c compounds act as intermediates in the krebs
what happens to the lactate produced in anaerobic resp
transported to the liver via the bloodstream where it is oxidised to pyruvate
can enter the link reaction or be converted to glycogen
why nadh needs to be reoxidised
so it can enter glycolysis again and become reduced again in order to allow tp to become oxidised again to form pryuvate and 2atp molecules along with it
what happens to during anaerobic respiration in some microorganisms
only glycolysis can continue pryuvate is decarboxylated to ethanal and ethanal is reduced to ethanol using reduced nad to oxidise the nad for further glycolysis
ethanol disadvantages
cells die when ethanol conc is high above 12
ethanol dissolves cell membranes
how acetyl coa is formed in the link reac
pyruvate is oxidised and co2 is released and then coenzyme a is added
how to measure the rate of respiration for an animal or smth using like apparatus
diameter or like size
mass
and distance and time
how anaerobic resp of glucose in a muscle cell differs from yeast cells
ethanol vs lactic acid
co2 released by yeast not muscle cells
if aerobic respiration had been investigated rather than anaerobic respiration how would you expect the volumes of gas collected at 30 degrees to differ from these results
vol less as no gas evolved
as vol of co2 evolved= vol of o2 taken in
explain why muscles become fatigued when insufficient oxygen available
lowers the ph, increases acidity,
enzymes inhibited not denatured
some of the lactate is oxidised to pyruvate by muscles when they are well supplied with oxygen, suggesr an advantage of the lactate being oxidised in the muscles
pryuvate is an energy source so muscles have an immediate energy supply
does glycolysis occur in the mitochondria
no
