Respiration q's Flashcards
w, z, x, w
why does aerobic respiration yield fewer molecules of ATP than the theoretical maximum?
- some ATP used to actively transport pyruvate into the mitochondrian
- some ATP used to actively transport H+ from reduced NAD formed in glycoloysis
- some energy released in ETC, is releases as heat
- not all the H+ movement back across membrane is used to generate ATP
- not all the reduced NAD is used to feed into the ETC
Explain why the incomplete breakdown of glucose in anaerobic respiration produces less ATP than aerobic respiration
in anaerobic
- glycolysis/ conversion of glucose into pyruvate occurs
- produces 2 molecules of ATP (net)
- only substrate level phosphorylation ocurrs
- O2 not available as final electron acceptor
- pyruvate used to regenerate NAD for glycolysis to continue
- krebs cycle + ETC / chemosmosis / oxidative phosphorylation doesnt occur
describe the pattern of respiration shown by cauliflower at increasing storage temperatures of 0 celcius to 20c (table)
as temp incr, respiration rate incr
respiration rate double w/ a 10 c temp increase
discuss what the data in table 5.1 indicate about the best conditions for staorage of fruits + vege
- best conditions are lower temps bc respiration rate is low
- 0c/ freezing could be the best
- 0c/ might be too low as food cells might be damaged at 0c
- some food storage temo doesnt seem to matter
- data is incompletet for potato / parsnip so no conclusions can be made
- if product needs to ripen during storgae then a higher temp / not above 20c will be ideal
identify w/ reasons which fruit or vege listened in table 5.1 is least likely to spoile during storage
- onion
- has lowest respiration rate
- across all temps
- can be kept at room temp
which fruit / vege listed in table 5.1 is likely to be the most difficult to keep fresh during storgae? give a reason for ur ans
- asparagus
- has a high respiration rate across all temps
certain parasites live in blood of mammals
suggest why even though blood carries O2, these parasites are adapted to respire anaerobically
- parasites have little access to O2
- inaccesible bc little O2 dissolved in plasma
- inaccesible bc little O2 combined w/ HB
- Hb has greater affinity for O2 than parasite pigment
- bc the O2 is bound to Hb the parasite is unable to use it
the anaerboic respiration in animal cells can be reversed, but the anaerobic repiration pathway in yeast cells cannot be reversed.
explain why, using ur knowledge of the differences between the 2 pathways
in animals
- pyruvate is converted to lactate
- can be reversed as no other product formed
- lactate dehydrogenase available to reverse the reaction
in plants
- pyruvate converted to thanol ( in 2 steps) + co2
- cannot be revered as CO2 is lost
- dehydrogenase enzyme cannot reverse the reaction
state precisely where the in the cell glycolysis occurs
cytoplam of cell
outline the process of glycolysis
- phosphoryation of glucose
- so forming hexose 1, 6 bisphosphate
- then forming of 2 triose phosphate
- for formation of pyruvate oxidation occurs
- pyruvate produced from TP
- total production 4 ATP/ net production 2 ATP
W - Ethanal
X - CO2
Y - reduced NAD
Z - NAD+
w/ ref to table 5.1 describe the effect of the diff treatments on the alcohol conc of the treated samples compared w/ the control samples
a : produced less alcohol than the control at all times
v: had the same alcohol as the control at 15 hrs
c: produced more alcohol than the control at 15+ 60 hrs
suggest a reason for the dif in alcohol conc at 60 hrs between the 2 bark treatments v and c
at 60 hrs
- C has more yeast cells
- only a small no. of bacteria in V are producing alcohol
to be used as a source of comercial sugar , the sap needs to be as uncontaminated as possible. suggest w/ reason , which of the treatment shown in table 5.1 would be the best for use w/ sap so that it is suitable as a source of commercial sugar
A,
has the least contamination as it has very few bacteria + little alcohol
product: urea
organ the product is transported to : liver
-hepatocytes can tolerate lacatate which would otherwise be toxic
- hepatocytes have enzymes to metabolise lactate
- conversion of lactate require O2 + muscle cells dont have enough O2
explain what might happen to a person if the liver did not break down insulin
- blood glucose conc woud fall too low (causes hypoglycaemia )
- glucose continued to be taken up by cells results in low blood glucose
- mitochondria eventually cannot generate enough ATP as less avaibake glucose in blood
- death
- build up of lactate kills liver cells
- disruption of enzymes as a reuly of low pH
- lack of fatty acids not avaiable for respiration
- lack of oxidised NAD for metaboilc reactions
- some deamination cannot occur
- build up of fatty acids present in fat deposits
state precisiely where in the liver cells the excess reduced NAD can be re oxidised
cristae
suggest the type of reaction that removes a phosphate group form an ATP molecule
hydrolysis
1
none
2/3
state the precise location of the ETC in the cell
cristae
describe the differences observed in the seeds in groups a b and c
A has more stain than B
and C has none
suggest reasons for the results observed in the seeds in group A
- shaded areas in A are respiring
- 22c is suitable temp for respiration
- reduced NAD produced in glycolysis/ link reaction/ krebs cycle
- more electron transfer to TTC (electron acceptor)
suggest reasons for the diff in the amount of staining observed in the seeds in groups B and C when compared to those in group A
- respiration uses enzyme
- group b: not enough energy for ESC formation
- group c : enzymes denatured by high temperature
i) ethanal
ii) ethanal
iii) Co2 and ethanol
explain why this pathway (anaerobic pathways after glycolysis) is important for plant cell
- release NAD to accept more H+
- some ATP available for active transport
a) krebs cycle, link reaction
b) oxidative phosphorylation
suggest why at each temp , respirator B contained some glass beads
- to make the vol of contents the same in the respirometer
- the vol of peas in A is greater than the vol of peas in B
suggest how the student determined the quantity of glass beads to place in repirometer B at each temp
- determined by finding diff in vol between soaked peas to dry peas
- the diff represents the vol of glass beads required
- calc vol of 1 bead to determine no. of beads equivalent to vol required
explain why there is an inceased rate of respiration in soaked seeds at 25 c compared w/ soaked seeds at 15 c
- at high temp 25 c , incr kinetic energy
- named respiratory enzymes involved
suggest a reason for diff in ROR between soaked + dry pea seeds
- reaction need to take place in solution
- enzyme + substarte can move in soaked seeds
- soaked seeds need more ATP
- for protein synthesis
mammal : pyruvate , no , lactate
yeast: ethanal, yes, ethanol
suggest one benefit of anaerobic respiration to an organism
- ATP produced
- recycles NAD
- allows glycolysis
W: glycolysis
X: calvin cycle
Y: krebs cycle
- takes place in diff parts of the cell
- glycolysis in cytoplasm
- calvin cycle in cholorplasts / stroma of choloplast
- krebs cycle in martix/ mitochondrion
statte the products of oxidative phosphorylation
ATP
H2O
oxidised NAD
explain the role of coenzymes in this leaf cell, w/ respect to the metabolic reactions outline in fig 3.1
- NAD/ FAD can accept hydrogen
- reduced NAD/FAD supplies e- for ETC
- Reduced NAD/FAD supplies H+ for chemiosmosis / oxidative phosphorylation
- reduced NAD supplies H to calvin cycle
- Coa carres acetate to krebs cycle
describe + explain the role of ATP in the cell
- energy ‘ currency’/ transfers energy
- phosphate can be removed by hydrolysis
- to provide 30 kjmol-1 energy
- energy released for metabolism
- ADP can attach a phosphate from ATP during PS
- energy released in suitable quantity to prevent cell damage
name the specific process that is carried out by crista in the mitochondrion
oxidative phosphorylation
- substrate respired changes over time
- initially respires carbohydrate
- decrease in RQ indicates lipid as substrate
- carbohydrate used up overtime
- proteint not likely to be used as substrate/ proteins only used as a last resort
describe the way in which an endothermic animal , such as a mammal, normally prevents its body temp from decreasing when the external temp decreases
- peripheral thermoreceptors stimulated by decrease in external temp
- impulses sent to hypothalamus
- vasoconstriction of arterioles to reduce heat loss
- prevents heat loss by conduction
- increased metabolic rate to generate heat energy
- release of adrenaline
- shivering to generate heat energy
- hair raise to trap heat
i) glycolysis
ii) cytoplasm
iii) D- ATP, E- NAD, F- pyruvate
in anaeribic conditions , pyruvate doesnt proceed to the link reaction.
desrcribe the fate of pyruvate during anaerobic respiration in an animal cell and explain the importance of this reaction
- pyruvate converted into lactate
- pyruvate accepts hydrogen atoms
- hydrogen from reduced NAD
- catalysed by lactate dehydrogenase
- no O2 to act as final e- acceptor
- so krebs cycle cannot take place
- NAD recylced
- cell glycolyisis to continue
- small amount of ATP can be produced
suggest how the seal is adapted to respuire for such a long time underwater (physical)
- large nostroles open to take in air
- when submerged nostrils close to keep air in
- lungs have high vital capacity
suggest how the seal is adapted to repsire for such a long time underwater (respiration)
- seal has lower metablic rate
- able to respire anaerobically for a long time
- large supplies of NAD to accept H
- this prevents build up of lactate
- seal tolerates lactate
- seal tolerates incr co2 conc
- seal tolerates low pH
suggest how the seal is adapted to respire for such a long time underwater (synoptic)
- blood diverted from certain regions
- plently of Hb
- Hb has a higher affinity for O2
describe the pattern of growth of the yeast population in this fermenter ( overall trend , shape : curve straight etc, fig)
- slow incr during day 1
- esponential increase
- rate of increase less steep during day 1
- stationary phase
- day 2 , yeast pop % 24
fig 5.1 shows that as the sugar conc decreases the ethanol conc increase. explain this relationship
- sugar converted to ethanol
- in anerobic respiration
- sugar undergoes glycolysis
- pyruvate loses CO2
- reduced NAD gives hydrogen to ethanal
- NAD being recycled so glycolysis continues
- pyruvate decarboxylase
explain why ethanol is considered to be a primary metabolite of yeast
production of ethanol increases as yeast pop increases
outline how 2 factors may limit the max size of the yeast pop
- sugar conc falls too low
- pH falls too low
- high enthanol conc damages yeast
- glucose enters glycolysis w/o being broken down
- maltose must be hydrolysed
- enzyme only made when glucose is running out
- enzyme induced
- transcription + translation / protein synthesis takes time
- enzymes to bread down malotriose made list
adv of using yeast
- less energy required
- doesnt need incr temp / incr pressure
- can use waste material as a substrate
- substrate is sustainable
- process doesnt use up fossil fuels
- product is carbon neutral
- yeast is easily accessible
dis of using yeast
- time consuming
- needs purification of product
- is killed by product
- can only use batch method
- sterile conditions required
- less ventiliation
- less O2 for aerobic respiration
- so less ATP produced
- increased acidity as CO2 build up interfering w/ enzymes
- less glucose uptake into cells
- less glucose for ATP production
- glucose not converted to glycogen
suggest how a weak + irregular heart beat could result in fatigue
- slow rate pf blood flow
- less O2 for aerobic respiration
- decr glucose for respiration
- so decr ATP produced
- incr acidity as CO2 builds up, interfering w/ enzymes
outline the consequences of an inefficient transfer of pyruvate itno mmitochondria + link this to the symptoms of CFS .
- less pyrivate for krebs cycle
- no oxidative phosphorylation
- less ATP for muscle contraction
- anaerobic respiration takes place
- lacate causing aching muscles
suggest a reason for the poor specific immune response in ppl w/ CFS
- B lymphocytes dont respond to cytokines
- little ATP for B cells mitosis
- Little ATP for production of antibodies
i) mitochondria
ii) - molecules are not lipid soluble to require protein channels to cross membrane
- AT ornithine+ citrulline need to be moved into + out of mitochondrion more quickly than would be met by diffusion
- facilitates diffusion - conversion of ornithine ino citrullline creates conc gradients
how has the ammonia that is used in step 1 been formed?
deamination / removal of NH2 group from amino acid
identify the compound labelled X
ATP
give one limitation of using this method to investigate respiration rate
- measurements only taken every 30 sec
- difficult to read the meniscus (may be subjective)
identify 1 variable that had not been controlled in this experiement + suggest an improvement to control that variable
- v: mass of seeds not given ; I: take the mass of the seedlings at the start
- v: the capillary tube internal diameter is not given ; I: use a CT if length 20cm+a 1mm internal diameter
- v: temp not controlled ; I: allow apparatus to equilibriate to temp , before taking readings
describe how you would add the red fluid to the capilary tube at the start of the experiment
dipped into a small beaker + allowed to run
the data shows an anomalous at 60 seconds. explain why the result is sconsidered to be anomalous + describe one correct way of dealing w/ this type of result
- it is more than 10% from the mean/ diff from other datat at 60s
-anomaly should be identified + excluded from processing - aanomlay must be identified but could be included in calc
-repetition to obtain another reading
what additional info would be needed to calc:
i) the vol of O2 taken up by the seeds
ii) the O2 uptake for this batch of seeds to be comparable w/ data from another type of bean
i) the internal diameter of the capilarry tube
ii) the mass of the bean seeds
experiment:
- mass of invertebrate + mass of the beans is the same
- safe+ethical use of invertebrate eg, ass screen so that animal cannot touch the muslin bag
- bigger syringe needed (5-10cm3)
- keept temp+ light constatnt
- use same mass of soda lime in both assays
- measuring distance moved by coloured red liquid at regular time intervals
- repeat experiments
results+ conclusion
- invertebrates ROR is expected to be higher than the ROR of the beans bc invertebrates are moving around
- metabolic processe requires energy/ generate heat
how might scientists a century ago have known that termites evolved in thjhe jurassic geological period?
fossils in rocks
what new source of evidence might help todays scientists to find out how closely related termites are to cockroaches
DNA/cytochrome C
explain how CO2 produced in the respiring body cells of wroker termites is removed to the air outside the termite mound
- CO2 diffuses doon the conc gradient out of respiring cell
- carried through body from cell by blood passing out via trachea
- respiration generates heat
- hot gases expand + are less dense so rise up by convection through the mound to vents at mound- top
siuggest why the african termites need to build mounds in this shape + orientation
- shape: large sa:vol ratio
- smallest area exposed to greatest heat
- increased vol of water aded to seedling , leads to lower survival of seedlings
- larger decrease in survival for added water from 30cm3
- vol of water has no effect on no. of seedlings surviving up to the first 3 days
- quote data points to support any point
aerobic respiration
- no O2 so no aerobic respiration occurs
- no link reaction/ krebs cycle/ ETC/ oxidative phosphorylation
- no O2 to ac as the final e- acceptor
anaerobic respiration respiration
- plant has to switch anaerobic respiration
- only glycolysisi occrus
- NAD regenerated for glycolysisi
- pyruvate to ethanal to ethanol
- pyruvate decarboxylase
- only 2 ATP
consequences
- ethanol is toxic
- alcoholic fermentation is irreversible
- less ATP procduced
- no AT
- Root hair cells cannot take up mineral ions by AT
- so plant cannot make proteins
- cannot generate WP gradient into roots
- water cannot be absorbed (so cell cannot remain turgid)
- no PS
give 2 structural features of mitochondria that support the endosymbiosis theory
- size similar of that of a bacteria
- contain circular DNA
- may have plasmids
- have double membranes
explain why early eukaryotes were able to grow more quickly than cells that did not possess mitochondria
would be able to respire aerobically
this produces more ATP
ATP needed for active transport / cell division
more ATP allows further metabolic reactions
explain why at the end of the day , only a small proportion of the students mass was ATP
- ATP is hydrolysed to ADP
- ATP is constantly recycled
- ATP used to provide enegrgy for metabloic reactions
- ATP is used immediatly/ not stored long term
describe 2 ways in which the structure of mitochondrial membranes is related to the function of a mitochondrion
- contain ETC
- provide surface for chemiosmosis
- allows maintenance of H+ gradient
- outer memebrane is highly permeable to allow movement of molecules
U : matrix
W : crista
Z : inter membrane space
cyanide: prevents aerobic respiration
fluoride prevents anaerobic respiration
describe the production of ATP by substrate- level phosphorylation (addition of phosphate) in different stages of respiration w/ reference to the no. of ATP molecules produced
- 2 ATP molecules per glucose from glycolysis
- when TP converted to pyruvate
- 4 ATP made but 2 used up in glycolysis
- ATP produced per turn of the krebs cycle (1)
- when 5 carbon compound is converted into 4C compound (oxaloacetate)
suggest why the use of fructose allows naked mole rats to survive w/o O2 for a long time
- glycolysis can continue
- bc conversion of glucose to TP is not needed
- ATP is produced when TP is converted to pyruvate
suggest one other aspect of the physiology of naked mole rats that explain how they are able to surivive w/o O2 for a long term
- slow metabolic rate
- less energy spent on thermoregulation
alanine : both have 3 carbons
akutanic acids : both have 5 carbon atoms
aspartic acid: highest proportion of O2 atoms in its structure
outline the reactions that must occur to convert alpha ketoglutaric acid to oxaloacatate
- decarboxylation/ CO2 produced
- dehydrogenation / hydrogen removal
- ATP prodcued
- 4c intermediate produced
what is the precise location of the link reaction withint cells
matrix of mitochondrion
i) 16 c atoms in fatty acids ; 2 c atoms in acetyl coA which enters krebs cycle
ii) acetyl coA (2c) is produced form pyruvate ( 3 C atom) in link reaction
suggest a role for coenzyme other than coenzyme A in beta oxidation
- FAD accepts hydrogen atoms
K: acetyl group of coA
L: Citrate
M:co2
N:oxaloacetate
name the process reperesented by the letter Q
substrate level phosphorylation
coenzyme A + ADP/ATP
coenyme A:
- transfers acetly from link reaction to krebs cycle
ADP/ATP
- phosphorylation (addition of) of glucose to form hexose 1 6 bisphosphate in glycolysis
- dephosphorylation (removal of) of TP in glycolysis
- dephosphorylation of intermediate in krebs cycle
- formation from substrate level phosphorylation
- formation from oxidative phosphorylation, harnessing chem energy from chemiosmosis
NAD + FAD
NAD
- removal of H from TP in glycolysis
- removal of H from pyruvate in link reaction
- removal of H from intermediate in krebs cycle
- addition of e- to ETC
- addition of e- to pyruvate in lactate fermentation
- addition of e- to ethanal in alcoholic fermentation
FAD
- removal of H from intermediate in krebs cycle
- larger no. of proton pores result in protons leaking back into matrix
- reduced yield of ATP from chemiosmotic gradients
- less TAP is made from oxidative phosphorylation
- more energy wasted as heat
- energy from chemiosmosisi decoupled from ATP synthesisi
- energy yield from aerobic respiration reduced per molecules of glucose
- food not converted to ATP as efficiently
- less excess energy intake in diet
- less deposition of fat
- fat stores may be respired for energy
name the components labelled U and Q
U - ATP synthase
Q - electron carrier
name the 2 regions labelled P and S
P - intermembrane space
S- matrix
name the 2 processes labelled R and T
R - krebs cycle
T - ATP synthesis
what properties of the mitochondrial inner memrbane allow chemiosmosisi to occur
- mostly impermeable to H+
- large SA
- presense of ATP synthase
describe 2 quantitative changes in intermembrane space which occur as a result of oxidative phosphorylation
- decr pH
- becomes more +tively charged
outline the processes involved in the generation of ATP through chemiosmosis
- occurs in mitochondria
- involves inner membrane + matrix
- involved movement of hydrogen across membrane
- use of ATP synthase
- H+ions pumped out of matrix across membrane into intermembrane space
- proton gradient created
- H+ ions pass through hydrophilic transmembrane protein
- cristae involved
-ATP synthase produces ATP from adp+ pi - h+ ions move from an area of high conc to low conc
- some h+ ions lead back into matrix
outline how ATP is produced in mitochondria by chemiosmosisi
- establishment of H+ ion gradient
- H+ ions flow down a conc gradient
- from intermembrane space to matrix through ATP synthase
- energy to join ADP +Pi to form ATP
there is a graph for this
- incorrect bc one yeast produced more CO2 in anaerobic conditions
-incorrect bc error bars overlap
graph
random error bc some experiments lrge SD/error bars
ribosomes
- respiration is anaerobic
- respiration decreases rapidly once glucose used up
- ethanol used once glucose has been consumed
-aerobic respiration of ethanol - bc acetly coA used in krebs cycle
- respiration stops when ethanol has been used up
decribe 2 pratical considerations to ensure the s . cerevisiae pop grows successully when the initial culture is established
- use aseptic techniques
- provide sources of nutrients
- incubate at suitable temp
it only respires in the absence of oxygen
it hydrolyses a peptide bond between 2 amino acids which are joined by a disulfide bond
suggest how these sprinters can expend so much energy without needing to carry out aeorbic respiration
- cells are able to tolerate high levels of lactate
- have high phosphocreatine stores
- use of stored ATP
suggest + explain why cheese has the highest energy content of the foods in this table
-cheese is high in fat which has the highest kcl per 100g
- fatty acids have many H atoms
- can be oxidised many times in krebs cycle
- so reduce many NAD
- cookie 2 is protein cookie
- RQ of cookie 2 is 0.94 + RQ of cookies 1 is 0.98
- lower RQ means cookie 2 must have more protein
-RQ closer to 1 means more carbohydrate
- maggot will not produce CO2 during lactate fermenation
- yeast will produce CO2 during alcoholic fermentation
- measuring RQ requires CO2 production
0w: mainly carbohydrate respired
50watts : more lipids respired
250watts : more anaerobic respiration
- take 1cm3 of culture +make up 10cm3
- need to make a total of four 1:10 dilutions
- 1:10 to 1:100
- ensure mixing of yeast suspension at each stage
state the equp that would be needed in addition to a LM to measure the average diameter of yeast cells
eyepiece graticule
stage micrometer
- rate of respiration is proportional to rate of gas production
- use a tamgent
- calc gradient of each line
- vol of gas divded by time
- compare the same time between sugars
correct
- slope of each curve is similar
- values for overall rates are similar
- eg calc values
against
- glucose respiration begins sooner than maltose
-glucose jas more rapid increase at begining
-lag before respiration of maltose
- maltose continues to incr as glucose is slowing down
- maltose may need to be hydrolysed before used in respiration
correct
- no lactate respiration
-lactose is disaccharide
- lactose was not hydrolysed
- yeast do not have the enyme to hydrolyse lactose
against:
- maltose /sucrose is a disaccharides
-maltose/sucrose are respired
- may be that lactose could be hydrolysed but cannot be absorbed
conclusion
- need stat anylasisi to determine significance
- t test/ SD
- measuring vol of gas over time only eztimate ROR
-Rinse equipment
- stir yeast solution
- yeast stock solution made from same type of yeast
- ensure connnection to gas syringe is tight
- check temp of water bath is 35 celcium
- boiled +cooled yeast/ use buffer instead of yeast
