12 Respiration Flashcards
describe what happens during the process of phosphorylation
- Two Pi groups;
- combine w a glucose molecule (6C) ;
- into Fructose 1,6 bisphosphate is produced/formed - unstable
- 2 ATP molecules used
state what occurs during oxidation of TP in glycolysis
- H+ lost by TP molecule
- H+ picked up by NAD;
- NADH is produced;
OILRIG
Oxidation
Gain of O2
Loss H+
Loss of electrons
Reduction
Loss of O2
Gain H+
Gain Electrons
State the net production of ATP and reduced NAD during glycolysis.
2 molecules of ATP AND 2 molecules of reduced NAD / NADH;
Explain why the link reaction is described as an oxidative decarboxylation reaction.
- Pyruvate is decarboxylated / CO2 is removed from pyruvate;
- Pyruvate is oxidised by the removal of hydrogen / dehydrogenation of pyruvate occurs
how many molecules of reduced NAD and FAD are produced at each stage per molecule of
glucose
Glycolisis= 2 NAD, 0 FAD
Link reaction= 2 NAD, 0 FAD
Krebs cycle= 6 NAD, 2 FAD
Oxidative phsophorylation= 0 NAD, 0 FAD
- location of ATP synthase
- transports hydrogen atoms
- nucleotide with a purine base
- location of substrate-linked phosphorylation
- enters the Krebs cycle
- produced by the oxidation of triosephosphate
- Inner mitochondrial membrane
- NAD
- ADP/NAD
- Cytoplasm
- Acetyl COA
- Pyruvate
State the precise location of glycolysis in the cell.
Cytoplasm
Outline the role of NAD in respiration in aerobic conditions.
- a coenzyme;
- in dehydrogenation/for dehydrogenase
- 3 ATP produced per NAD
- carries hydrogen atoms/P+E from krebs cycle and glycolysis TO ETC for oxidative phosp
-redox / reduction and oxidation reactions; - ATP produced
- Nad accepts H+ in glycolysis,krebs and link reaction
State the total number of molecules of carbon dioxide removed in the link reaction and Krebs cycle for each molecule of
glucose respired.
6
Outline the role of energy in living organisms
- ATP is universal energy currency
1) anabolic reactions= protein synthesis, trygliceride formation
2) active transport/exo/endocytosis/sodium potassium pump
3) movement e.g. muscle contraction / cilia beating / locomotion
4) Ea, activate glucose in glycolysis, temperature regulation, etc
Explain role of FAD and NAD in aerobic resp
- coenzyme in dehydrogenation
- H+/electron carriers to ETC/cristae for OP
- so that TP dehydrogatend
- in the link NAD reduced so pyruvate dehydroganted = actetyl COA
- in krebs both NAD and FAD reduced to regenrate oxalaceate
- recycle NAD/FAD
- reduced
- carries electrons and protons from krebs to ETC
- reoxidixsed —-> H+ removed
- ATP produced
IMM/cristae
Describe oxidative phosphorylation
- Reduced NAD/FAD transport H atoms to cristae/ETC
- H+ released from NADH
- H+ splits into Protons and electrons
- Electons pass along ETC
- Electrons pass along carrier proteins in cristae down energy gradient
- Energy released used to pump protons from matrix to intermebrane space
- Inner memebrane imperable to protons
- Proton gradient forms, higher H+ conc in IM than matrix
- Protons move down gradient= chemiosmosis
- Protons pass through stalked particles through ATP synthase which becomes rotated
- ATP produced through pshosphorylation (ADP+ Pi)
- Electrons transffered to O2
- Addition of proton to O2 = H20
How many ATPS, NAD, FAD in aerobic resp
Glycolysis = 2 NAD, 0 FAD, 2 Net gain ATP, 4 made ATP
Link reaction= O ATP, O FAD, 2 NAD
Krebs cycle= 2 FAD, 2 ATP, 6 NAD
Oxidative pshophorylation = 34 ATP per glucose
Total = 38 ATP
Number of FADH and NADH made
3 NADH per 1 turn and 2 FADH per 1 turn
Glycolysis= 2 NADH
Link reaction= 2 NADH
Krebs= 6 NADH (3 per turn) and 2 FADH (1 per turn)
Total= 10 NADH and 2 FADH
How many ATP made in ETC
Each NAD = 3 ATP
Each FAD= 2 ATP
So 10x2.5 = 25 ATPs
So 2 x 1.5 = 3 ATPs
Total =28 ATPS
Explain the effect of rise in temp in resp
- increase in ROR
- KE increases —> more ESC
- past opt = denaturation of E
Explain why oxidative pshophorylation is NOT possibel in abscene of O2
- requires proton gradient produced by ETC
- with no 02 ETC doesnt occur/ no electron flow
- NAD cannot reform/ NADH not oxidized
- O2 combines w Electron/ptorotn/oxygen final acceptor in ETC
Respiraory substrate
Carbs = 15.8KJ energy released AND 1.0 RQ
lipid= 39.4 energy released AND 0.7 RQ
Protein= 17.0KJ energy released AND 0.9RQ
Respiratory quotient defintion and equation
- volume of carbon dioxide produced ÷ volume of oxygen consumed
PER UNIT TIME
- ratio of the number of mols of CO2 produced to the number of mol of O2 taken in, as a result of respiration
state number of mols of Co2 removed in link and krebs for each mol of glucose
6
stages of glycolysis in anaerobic conditions in yeast
- Glucose phosphorylated by ATP
- Fructose 1-6 bisphosphate formed
- triose phosphate is dehydrogenated by NAD
- 2 ATP is made via substrate-linked phosphorylation
- 2 pyruvate formed by glycolysis
- 2 NADH formed by glycolysis
- pyruvate is decarboxylated
- ethanal is formed/reduced by NADH
- ethanal is reduced by alcohol dehydrogenase
- ethanol is formed
- irreverisble reaction
- NAD regernated
- so glycolysis can continue
Explain why less ATP produced when yeast respires in anaerobic conditions compared to when yeast respires in aerobic conditions
- only glycolysis occurs
- 2 ATP produced
-no oxygen as electron acceptor - pyruvate does not enter mitochondria
- chemiosmosis / oxidative phosphorylation does not occur
- (ETC / chemiosmosis / oxidative phosphorylation) produce most ATP ;
- pyruvate / ethanal, converted to ethanol ;
Examples of anabolic reactions in a mammal that require ATP as an energy source. (2)
1) protein synthesis
2) making polysaccharides
3) making triglycerides
4) making polynucleotides / DNA / RNA
5) phosphorylation
Describe how the structure of ATP is related to its role as energy currency. [3]
1) small
2) found in all organisms
2) water-soluble so can move around in cell
4) easily hydrolysed to release energy
5) loss of Pi leads to large quantity of energy released (30.5 kJ mol-1
6) rapid/high turnover rate
7) reversible reaction/ recycled/regenerated
8) immediate energy donor
ATP synthesis
1) by chemiosmosis
2) ATP is generated using potential energy, from the transfer of electrons by electron carriers in the ETC
3) protons flow down their conce gradient via FD through ATP synthase
4) transfer of 3H+ = produces 1 ATP mol if ADP and Pi are available inside the organelle
5) as protons travel through ATP synthase, it drives down part by rotation force provided by electrochemical gradient that produces AT
simple respirometers, to determine the RQ of germinating seeds/small invertebrates (e.g. blowfly larvae)
….
where each of the four stages in aerobic respiration occurs in eukaryotic cells:
- glycolysis in the cytoplasm
- link reaction in the mitochondrial matrix
- Krebs cycle in the mitochondrial matrix
- oxidative phosphorylation on the inner membrane of mitochondria
Occurs in cytoplasm
Outline the process of glycolysis in a mammalian cell. [6]
- glucose phosphorylated (SLP) using 2 ATP molecules
- raises energy level of glucose / lowers activation energy of reaction
- results in formation of fructose/hexose biphosphate (6C)
- fructose biphosphate is lysed/lysis of hexose/glucose
- 2 TP produced (3C) (6C –> 2 x 3C)
- H+ atoms and Pi groups removed from TP by coenzyme NAD (dehydrogention)
- produces 2 molecules of pyruvate (2C) and 2 NADH
- removed Pi groups added to ADP to produce 4 ATP, however since 2 were used there’s a net gain of 2 ATP
- NADH to OP for redox reacction
MM
Link reaction
1) pyruvate is decarboxylated (CO₂ is removed)
2) dehydrogenated (H+ removed and picked up by NAD), this converts pyruvate into a 2C compound/acteyl group
3) then it’s combines with coenzyme A (CoA) to produce acetyl coenzyme (ACoA)
4) coenzyme transfers acetyl group with 2C to Krebs Cycle
5) 0 ATP produced
ACetyl COA transported to krebs cycle
When O2 avail how does pyruvate enter link reaction
pyruvate enters by AT from cytoplasm into the mitochondrial matrix
MM
Krebs cycle
1) Acetyl coA combines with oxaloacetate (4C) to form citrate (6C)
2) citrate is decarboxylated and dehydrogenated
3) to 5C compound
4) 5 to form, only NAD
3) 1 FADH, 3 NADH and 2 CO₂ are produced by reduction as they gain H+
4) ATP produced
5) Subst level phosp
6) enzyme caalysed reactions
- oxaloacetate is regenerated and can recombine with ACoA
- oxaloacetate (4C) acts as an acceptor of the acetyl coenzyme A to form citrate (6C), FAD
- which is converted back to oxaloacetate in a
series of small steps
number of ATP molecules produced during Krebs Cycle
2 molecules of ATP from every pyruvate molecule
types of anaerobic respiration
alcoholic fermentation and lactic acid fermentation
SS and fucntion of mitochondria
- makes ATP
- double memb; inner is folded to form cristae + increases SA
- 0.5- 1.0 um
IMM:
* folded/cristae large SA
* has ATP synthase
* has ETC
* Site of OP
* imperable to protons
IMS:
* protons pumped into IMS
* high conc of protons
* ATP synthesis
* proton gradient between IMS + matrix
* protons diffuse from IMS to matrix
Matrix:
* contains coenzymes for krebs/link reaction
* site of link reaction/krebs cycle
* 70s ribosomes
* circular DNA
suggest why 1g of fat will produce more ATP than 1g of carbs as resp subs
- more C-H bonds
- more C-C bonds
- more O2
- more NADH/FADH produced
- More H+ atoms to build up proton gradient
- more chemiosmosis/OP
- more H+ pumped across IMM
mammal vs yeast anerobic resp diffrences
mammal:
- reduction of pyruavte
- lactate end product
- no decarboxylation/Co2
- lacate dehydrogenase
- 1 stage
- reversible
Yeast;
- reduction of ethanal
- ethanol end product
- Co2
- alcohol dehydroeganse
- 2 stages
- irreversible
mammal vs yeast anerobic resp similarities
- involve glycolysis
- occur in cytoplasm
- made 2 net ATP
- regerate NAD from NADH
Chemiosmosis in mitochondria vs chloroplast
Mitochondria:
- OP
- Cristae
- NADH/FADH gives H+
- H+ enters IMS
- O2 is final e- acceptor
- Makes H2O
Chloroplast:
- Photophosyph
- Thlakoid memb
- photolysis
- H+ from Ps1
- H+ enters thylakoid space
- NADP final e- acceptor
- Makes NADPH
Describe respiration in yeast cells in anaerobic conditions. [7]
1) pyruvate formed by glycolysis
2) reduced NAD formed by glycolysis
3) pyruvate decarboxylated by
4) pyruvate decarboxylase producing
5) ethanal
6) ethanal is the hydrogen acceptor
7) from reduced NAD
8) ethanol formed, this reduction is catalysed by
9) alcohol dehydrogenase
10) irreversible (so chemical potential energy of ethanol is wasted)
11) NAD regenerated so can accept more hydrogen atoms
12) so glycolysis can continue
lactate pathway (mammals)
- only glycolysis occurs
- pyruvate cannot enter mitochondrian/stays in cytoplasm
2)pyruvate accepts the H+ from NADH and converted to lactate by lactate dehydrogenase (3C)
3)when overcome O2 debt= converted to glycogen
2) again NAD is released and allows glycolysis to continue
3) produces small amount of ATP/2 ATP in subt
adaptations of rice to grow in wet conditions
- Cell tolerant to high levels of ethanol conc = when roots submereged in water less O2 avail then whe air spaces avail so cells respire anaeerobically producing alcohol
- Stems have aerenchyma w large air spaces, helps/allows O2 from air to diffuse down to roots
- Long stems so leaves above water = leaves exposed to air, facilities gas exchange for photosynth and resp
- shallow roots so air trapped on underwater leaves
Suggest the functions of the DNA and ribosomes in a mitochondrion.
1) DNA for transcription (codes for mRNA)
2) ribosomes for translation
3) synthesis of respiratory enzymes and inner membrane proteins
State two ways in which the structure of ATP differs from the structure of an adenine nucleotide in a DNA molecule.
contains ribose not deoxyribose and has three phosphate groups not on
mechanism of redox indicators when determining respiration rates
1) dehydrogenation happens regularly throughout the different stages of aerobic respiration
2) the hydrogens that are removed from substrate molecules are used in oxidative phosphorylation and are transferred by NAD and FAD
3) when DCPIP and methylene blue are present, they can also take up hydrogens and get reduced (blue -> colourless)
4) faster the rate of respiration, the faster the rate of hydrogen release and faster the dyes get reduced and turn colourless
5) therefore the rate of colour change can correspond to the rate of respiration in yeast
5) rate of respiration (sec^-1) = 1 / time (sec
why without O2 does pyruvate need to be converted to lactate
- NAD regenerated
- so glycolysis can continue
- to produce ATP
describe what happens to H+ released during link reaction
- accepted by NAD
- passed to ETC
- for Op/chemiosmosis
explain why glucose needs to be converted to fructose bisphosphate
- provides Ea to split
explain sig of diff values that mayu be obtained by RQ
- depends on subst
- greater than 1= anerobic resp
why cant OP occur in abscence of O2
- requires proton gradient produced by ETC
- w/ no O2 ETC doesnt occur/no electron flow
- NAD not reformed/NADHcannot be oxidised
- O2 combines w proton/O2 is final e acceptor
explain how NAD regernated
- reduced NAD
- to ETC
- oxidiesed/gives up H+
outline how this apparatus is used to measure the rate of O2 uptake by a knows mass of germinating seeds
- allowed time to equillbriate
- record level of fluid in manometer
- change in known time
- repeat
- open clip and reset level
- e.g 2cm/units
- use boiled seeds as a control
- soda lime absorbs CO2 given off
- do calculation
Role of mitochondrial matrix in resp
- site of krebs
- DNA/ribosomes for production of proteins
- Electron acrriers
- produces FADH and NADH for OP
- subst linked phoso
role of CoA
- binds to, acetyl (group) ;
- 2 acetyl / 2C fragment, + oxaloacetate citrate ;
- joins link reaction and Krebs cycle ;
describe condition needed for pyruvate to enter mitochondria by AT
- O2 aval
- ATP/energy needed
-IMM impermeable (to pyruvate) - carrier (protein)
- lower conc of pyruvate outside mitochondrion
- against concentration gradient ;
explain how rice is adapted to grow with its roots submerged in water
- aerencyma in stems and roots
- helps o2 diffusr to roots/submerged parts
- shallow roots so air trapped on underwater leaves
- greater/fast internode growth
- growth regulated by giberellin
- anerbic resp in roots when underwater
- tolerant to high ethanol conc
- ethanol dehydroganse switched on in anerobic conditions
explai why people breathe deeply after excercise
- to repay oxygen debt
- convert lactate to pyruavate
- reoxygenate Hb
- convert lactate to glycogen
- EPOC
chemiosmosis in mitochondria vs chlorplasts
Mitochondria:
- OP
- IMM/cristae
- NADH/FADH give H+
- H+—> IMS
- O2 final E- acceptor
- makes H20
Chemiosmosis:
- Photophosp
- thylakoid memb
- Photolysis/Ps1 gives H+
- H+—>Thlakoid space
- NADP final e- acceptor
- makes NADPH
