cellular respiraitn Flashcards
Photorespiration
a wasteful process in C3 plants that is intitiated by RuBisCO binding with oxygen instead of C02 due to high 02 concentrtaion asa result of the stomata closing, thereofre negatively impacting C3 plants where this occurs BECAUSE no glucose is produced
Functionof ATP, NADH, FAD Mitochodnria, glucoseand oxygen in cellular respiratio
ATP: Provides energy for the cell for growth, repair and division.
NADH: Carries hydrogen and electrons to the Electron transport chain to produce ATP by joining ADP and Pi.
FAD: An unloaded coenzyme. Once loaded with hydrogen and electrons, it is transported to the cristae for the electron transport chain to produce
ATP:
Mitochondria Where Krebs cycle and Electron transport chain of aeorbci cellualr repsiitotn occurs to produce atp.
Glucose: Used in glycolysis to produce pyruvate. Contains hydrogen that is carried by coenzymes used to make ATP.
Oxygen: Last acceptor of hydrogen to produce water in the electron transport chain.
The mitochondrion
a a double-membrane-bound organelle that is the site where krebs n etc of the areobic cellular respiration occur.
cellular respiration
the process by
which cells create usable energy
in the form of ATP from a series of
biochemical reactions, involving
the breakdown of glucose
What is glucose
va
simple 6-carbon
sugar molecule that is the amin produce of photosythensis and is the main energy source in aerobic celluar respiration to produce ATP and anaerobic respiration. Used to prodcuce ATP
Why is glucose broken down/why does cellular respiration occur
Glucose carries to much energy, that it cannot be useful in biochemical reactions in cells, therefore cellular respiration has to occur by breaking the energy stored in glucose down
What are the ways that glucose can be broken down to produce ATP
aerobic cellular respiration
anaerobic fermentation
Difference between aerobic cellular respiration and anaerobic fermentation
Aerobic cellular respiration requires oxygen and occurs in the mitochondria, specifically in the mitochondrial matrix and along the inner mitochondrial membrane cristae (for the electron transport chain).
Anaerobic fermentation does not require oxygen and occurs in the cytosol of the cell,
ATP
adenosine triphosphate,
a high energy molecule that,
when broken down, provides
energy for cellular processes
aerobic cellular respiration
cellular respiration that occurs in
the presence of oxygen. Involves
three stages, during which glucose
and O2 are converted into 30 or 32 ATP,
CO2, and water
anaerobic fermentation
a metabolic pathway that occurs
in the absence of oxygen. Involves
glycolysis, followed by further
reactions that convert pyruvate
into lactic acid in animals, or
ethanol and CO2 in yeast
what are the stages of areobic cellular respirtaion and where do these stages occur and
Occurs in three stages:
Glycolysis
The Krebs Cycle
The electron transport chain
Stage 1 (glycolysis) occurs in the cytosol of the cell. krebs cycle also known as TCA cycle occurs in the motochondroal matrixwhist electron rtransport chain occurs n the cristae of the mitochondria
Inputs and outputs of glycolysis of aerobic cellular respiration and explain this process
Inputs:
Glucose
2 ADP+Pi
2 NAD+ 2H+
Outputs:
2 pryuvate
2 ATP
2 NADH
Occurs in the cytosol of cells.
Glucose is broken down into two pyruvate molecules. Pyruvate is transported from the cytosol into the mitochondria for further breakdown.
Hydrogen and electrons from the breakdown of glucose is carried by a coenzyme NAD+ to become a high energy carrying molecule NADH. These are transported to the mitochondria to produce more ATP in stage 3.
2 ATP are produced
Inputs and outputs of Krebs cycle of aerobic cellular respiration and explain this process
Inputs:
2 Acetyl co-A(from 2 pryuvate)
Inputs:
2 Acetyl Co-A
FAD
NAD+
(ADP+Pi)
Outputs:
4 C02
NADH
FADH2
2ATP
Pyruvate from glycolysis is transported into the mitochondria. During this process, pyruvate combines with coenzyme A to form Acetyl Co-A. This produces 2 CO2 molecules. This is known as the link reaction.
In the matrix of the mitochondria, acetyl CoA is further broken-down into 4CO2 molecules. CO2 is released as a gas.
Protons and electrons are loaded onto NAD+ and FAD to produce high energy carrying coenzymes NADH and FADH2. These are used in the electron transport chain (stage 3).
2 ATP molecules are produced.
Inputs and ouputs of the electron transport chain nad explain the process
Inputs:
6 02
NADH
FADH2
26 OR 28(ADP+Pi)
Outputs:
2 H20
NAD+
FAD
26 OR 28 ATP
Electron transport chain occurs in the cristae OF THE MITOCHONDRIA, H+ and e- from NADH and FADH2 from glycolysis and Krebs cycle are unloaded. These e= and H+ are transported through the series of proteins, and protons pass through ATP synthase to produce 26 or 28 ATP. 02 accepts H+ to form water.
How do carrier molcules like ADP, CoA, FAD and NAD become high energy carrying molecules
when they are loaded with electns and protons
major purpose of the Krebs Cycle
to prepare for the final stage of photosynthesis, electron transport chain as its primary role is to produce NADH and FADH2, which are essential for the ETC.
How is ATP produced as an outputs of glyoclysis
by adding a phosphate onto ADP
What stage of aerobic celluar respiration and photosythensis produced the most energy
and why
The electron transport chain generates the most energy during cellular respiration because it uses high-energy electrons from NADH and FADH₂ to pump protons across the inner mitochondrial membrane, creating a proton gradient. This gradient drives ATP synthesis through ATP synthase, producing the majority of ATP—around 32 to 34 molecules per glucose molecule—via oxidative phosphorylation.
What happens if enzymes are not present
cellular aerobic respiraiton or anerobic repsiration or photosytehnsis will be much slower becauase tthen celluar processes cannot be catalaysed
What are the key Co-enzymes in cellular respiration AND their functions
ATP provides energy for cellular respiration to occur
NAD^+ serves as an electron carrier by accepting electrons and becomes reduced to NADH
FAD serves as an electron carrier by accepting and donating electrons, and facilicating ATP production and reduced to FADH2
CoA vCoA reduces nad+ to nadh and produces co2
what is the function of the electron transport chain cellular aerobic respiration
the electron transport
chain, produces the bulk of a cell’s ATP via aerobic cellular respiration, requires
oxygen accepts free protons and
electrons that have accumulated from the production of ATP to form water molecules
What happens if the electorn transport chian does not occur or exist
a
Without the electron transport
chain, the loaded coenzymes, such as NADH and FADH2, cannot drop off their electrons
and be converted back to unloaded NAD+ and FAD, and as ETC produces most of the cells atp, little atp will be produced
How does Anerobic fermentation produce ATP
glycolysis breaks down
of glucose into two pyruvate molecules. In doing so, it converts two NAD+ molecules to
NADH and produces two molecules of ATP in the absence of oxygen via alocjol femrnetation in yeast or lactic acid femrnentaiton in animals
how does glycolysis help in the functioning of a cell even if there is an absence of oxygen and elaborate the process in anaoerbic cellualr respiration
glycolysis can continue providing energy to the cell even if there is absence of oxygen as it breaks down glucose and produces 2atp, 2nadh and 2pyruvate
then the pyruvate is turned into lactic acid or ethanol recyling the nadh back into nad+
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7:34 PM
so the process can continue indefinitely even if there is no oxygen
compare anaerobic fermentation in animals and yeast
In yeast, glucose gets converted into pyruvate using 2 ATP and NADH Gets converted into NAD+, which produces ethanol and 2 C02 molecules
In animals, glucose gets converted into pyruvate using 2 ATP and NADH gets converted back into NAD+, which produces lactic acid.
However, both processes convert NADH back into NAD+ for glycolys
How does anaerobic fermentation affect the krebs cycle and electron transprot chain
Anaerobic fermentations inhibits/disrupts the krebs cycle and electron transport chain by disrupting the flow of of electrons and reducing the availability of NAD+, respectively
Process/process of the inputs and outputs of the anaerobic fermentation
Glucose is broken down into 2 pryuvate molecules and 2 ATP molecules. IN GLYCOLYSIS, In animals, lactic acid is produced, and in yeast, ethanol is produced NAD+ is loaded with H+ to form NADH and is recycled again to form NAD+, producing 2 C02 molecules.
Lactic acid fermentation process—process of anaerobic fermentation in plants
In glycolysis, glucose is broken down into pryuvate.
NAD+ becomes loaded with H+ to form NADH
Pyruvate is broken down into lactic acid during anaerobic fermentation
This causes NADPH be oxidised into NAD+ to be reused in glycolysis
Lactic acid cannot accumulate in the blood. Instead, when oxygen is avaliable, lactic acid is converted into pryuvate used in celluar respiraiton.
In what ways can yeast respire
aerobically by creating 30 or 32 ATP or and anaerobically by producing ethanol and 2 C02 and 2 atp
Ethanol fermentation process-anerobic fermentation occur in yeast process
nglycolysis, glucose is broken down into pryuvate.
NAD+ becomes loaded with H+ to form NADPH
pryuvate gets broken down into ethanol and c02
Ethanol diffuses out of the cell via passive diffusion to ensure fermentation can continue. However ethanol does not continue fermenatation when alcohol builds up in the external environment until alcohol does not diffuse out
What is ethanol fermenation used for
Beer, wine, bread and as a renewable source of fuel
1
q
what is the function of the electron transport chain cellular aerobic respiration
a
the electron transport
chain, produces the bulk of a cell’s ATP via aerobic cellular respiration, requires
oxygen accepts free protons and
electrons that have accumulated from the production of ATP to form water molecules
3
2
q
What happens if the electorn transport chian does not occur or exist
a
Without the electron transport
chain, the loaded coenzymes, such as NADH and FADH2, cannot drop off their electrons
and be converted back to unloaded NAD+ and FAD, and as ETC produces most of the cells atp, little atp will be produced
2
3
q
What happens in aerobic conditions
a
glucose is broken down in the presence of oxygen to produce carbon dioxide, water, and a large amount of ATP (adenosine triphosphate),
2
4
q
How does Anerobic fermentation produce ATP
a
glycolysis breaks down
of glucose into two pyruvate molecules. In doing so, it converts two NAD+ molecules to
NADH and produces two molecules of ATP in the absence of oxygen via alocjol femrnetation in yeast or lactic acid femrnentaiton in animals
2
5
q
how does glycolysis help in the functioning of a cell even if there is an absence of oxygen and elaborate the process
a
glycolysis can continue providing energy to the cell even if there is absence of oxygen as it breaks down glucose and produces 2atp, 2nadh and 2pyruvate
then the pyruvate is turned into lactic acid or ethanol recyling the nadh back into nad+
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7:34 PM
so the process can continue indefinitely even if there is no oxygen
1
6
q
Justifying why aerobic cellular respiration cannot progress in anaerobic conditions, as well as reasoning
why anaerobic pathways of metabolism require stages after glycolysis, helps you to better understand
the process of cellular respiration.
a
Aerobic respiration cannot occur without oxygen, because oxygen is needed as the final electron acceptor in the electron transport chain. Anaerobic pathways, like lactic acid fermentation in animals and alcoholic fermentation in yeast, regenerate NAD+ from NADH, allowing glycolysis to continue and produce ATP without oxygen.
2
7
q
compare anaerobic fermentation in animals and yeast
a
In yeast, glucose gets converted into pyruvate using 2 ATP and NAD+ gets converted into NADH, which produces ethanol and 2 C02 molecules
In animals, glucose gets converted into pyruvate using 2 ATP and NADH gets converted back into NAD+, which produces lactic acid.
However, both processes convert NADH back into NAD+ for glycolys
2
8
q
How does anaerobic fermentation affect the krebs cycle and electron transprot chain
a
Anaerobic fermentations inhibits/disrupts the krebs cycle and electron transport chain by disrupting the flow of of electrons and reducing the availability of NAD+, respectively
3
9
q
Compare were anaerobic fermentation and aerobic celluar respiration occur
a
anaerobic fermenation occurs in the cystol, whereas aerobic celluar respiration occurs in the mitochondrial matrix of the cell and the cystol and the cristae
5
10
q
Process/process of the inputs and outputs of the anaerobic fermentation
a
Glucose is broken down into 2 pryuvate molecules and 2 ATP molecules. IN GLYCOLYSIS, In animals, lactic acid is produced, and in yeast, ethanol is produced NAD+ is loaded with H+ to form NADH and is recycled again to form NAD+, producing 2 C02 molecules.
2
11
q
Lactic acid fermentation process—process of anaerobic fermentation in plants
a
In glycolysis, glucose is broken down into pryuvate.
NAD+ becomes loaded with H+ to form NADH
Pyruvate is broken down into lactic acid during anaerobic fermentation
This causes NADPH be oxidised into NAD+ to be reused in glycolysis
Lactic acid cannot accumulate in the blood. Instead, when oxygen is avaliable, lactic acid is converted into pryuvate used in celluar respiraiton.
2
12
q
In what ways can yeast respire
a
aerobically by creating 30 or 32 ATP or and anaerobically by producing ethanol and 2 C02 and 2 atp
2
13
q
Ethanol fermentation process-anerobic fermentation occur in yeast process
a
Inglycolysis, glucose is broken down into pryuvate.
NAD+ becomes loaded with H+ to form NADPH
pryuvate gets broken down into ethanol and c02
Ethanol diffuses out of the cell via passive diffusion to ensure fermentation can continue. However ethanol does not continue fermenatation when alcohol builds up in the external environment until alcohol does not diffuse out
2
14
q
What is ethanol fermenation used for
a
Beer, wine, bread and as a renewable source of fuel
2
15
q
When oxygen is present again, lactic acid is
metabolised back into pyruvate and used for aerobic cellular respiration. WHY
Lactic acid cannot accumulate indefinitely, as it lowers the pH of our cells( too acidic) and blood, and
can be toxic in high amounts
Define ethanol/alcohol fermentation vs lactic acid fermentation
ethanol fermentation is anaerobic fermentation that occurs in yeast, bacteria and plants where pyruvate produced via glycolysis is converted into 2 ethanol and 2 C02 (the product)
Lactic acid fermentation is anaerobic fermentation that occurs in animals where pyruvate is produced via glycolysis and is converted into 2 lactic acid molecules
How do yeasts contribute to the rising of bread during baking?
ethanol
fermentation,
Yeasts metabolize sugars, such as glucose in the dough, producing carbon dioxide, which allows the bread to expand and rise, while ethanol is removed during baking.
Why is ethanol diffused out
Yeasts are unable to metabolise ethanol into any useful products. and a build up of ethnaol is toxic to cells.Instead, ethanol diffuses
out of cells,
Compare the sustainability of aerobic cellular respiration vs anaerobic fermentation.
aerobic cellular respiration can continue indefinitely because its highly effiecnt at generating ATP, whereas anaerobic fermentation cannot occur indefintely due a toxic build up of lactic acid or ethanol.
What happens if an inhibitor blocks the electron transport chain
glycolysis can still occur because glucose can still be broekn donw into pyruvate and krebs cycle can still occur, however however the electron transport change cannot occur so the consequence is that means that only 4 ATP is produced
NADH AND FADH2 builds up in the cells because in the elecotrn transport chang eitll be unloaded but it cant be unloadedd anymore os it builds up this iis the effect of the inhibitors
What is the primary function of anerobic fermentation, considering its function is not primarily to produce ATP
The primary function of fermentation is to regenerate NAD+ to sustain glycolysis in the absence of oxygen, rather than to produce large amounts of ATP.
Why is oxygen referred to as the final acceptor
Oxygen is referred to as the final acceptor because oxygen mops up all the electrons that run through the chain
If a cell requires energy quickly, what process will it go under, why will it go under this process and what setbacks does this process has
If a cell requires neergyqucikcly it will underogoe anaerbboci fermenaiton because it will provide the cell with energy quickly, however fewer, only 2 ATP is produced per glucose. However, if the cell requires energy quickly for a short preiod of time this is okay because anerobic respiration is unlikely to run for prolonged periods.
4
36
q
Why does pryvuate get converted in alchol femrneaiton r lactic acid fermenation, why do these steps even occur if no atp is produced in them
a
the mechanism of alcohol femrneaiton or laticic ac fmenreaiton occur to oxidise NADH back into NAD+ for glycosis, so that atp can be produced again
2
37
q
What are the byproducts of alcohol fermenation
a
pryuvate gets converte dinto ethnaol, producing 2 c02 molecules and 2 NAD+ molecules as the byproducts whcih get cycled back to glycolysis
2
38
q
how is alochol femrneation used practially
a
alcohol femrnaiton is used to add yeasts to plant material to develop alcoholic beverages or ethanol can be used as a renewable fuel that does not pollute the enviornment and is the primary ingriednet in hand hand sanisiter.
2
39
q
Why is C02 not a byproduct of lactic acid fermentation
a
lactic acid is a 3 carbon molecule, instead pyruvate gets broken down into lactic acid, producing NAD+ as a byproduction without relaisng C02.
2
40
q
Despite all the differences between alcoholo and lactic acid fermenation, what are similarties between the 2
a
both processes occur in the cytoplasm
both processs can only produce 2 ATP
they are both a wayto make pyruvate less toxic to cells
3
41
q
why is aerobic celluar respiration so critical
a
there is a limit tomuch anaeorbic fermentation ATP can produce and only produces ATP for short periods of time thereofre is less reliable, Many processes require larger amounts of ATP to be produced for prolonged periods of time whihc ocucr via aerobiccelluar repsiraitoj eg. running a marathon
2
42
q
how does glycolysis help in the functioning of a cell even if there is an absence of oxygen and elaborate the process
if an unlimited glucose with no oxygen is present but a limited amount of nad is present, how can the cell continue to function
a
NADH gets oxidised to NAD+ to be recycled in glycolysis, as long as glucose is present the cell can continue respiring.
–
Why does pryvuate get converted in alchol femrneaiton r lactic acid fermenation, why do these steps even occur if no atp is produced in them
the mechanism of alcohol femrneaiton or laticic ac fmenreaiton occur to oxidise NADH back into NAD+ for glycosis, so that atp can be produced again
Despite all the differences between alcoholo and lactic acid fermenation, what are similarties between the 2
both processes occur in the cytoplasm
both processs can only produce 2 ATP
they are both a wayto make pyruvate less toxic to cells
why is aerobic celluar respiration so critical
there is a limit tomuch anaeorbic fermentation ATP can produce and only produces ATP for short periods of time thereofre is less reliable, Many processes require larger amounts of ATP to be produced for prolonged periods of time whihc ocucr via aerobiccelluar repsiraitoj eg. running a marathon
2
what are the factors effecting the rating of cellualr rspriation and explain
- Temperature:
Below the optimal temperature, enzymes and substrates have less kinetic energy so there are fewer reaction-inducing collisions.
Above the optimal temperature, enzymes begin to denature
and pH :Below the optimal temperature, enzymes and substrates have less kinetic energy so there are fewer reaction-inducing collisions.
Above the optimal temperature, enzymes begin to denature
- Glucose:Below the optimal temperature, enzymes and substrates have less kinetic energy so there are fewer reaction-inducing collisions.
Above the optimal temperature, enzymes begin to denature
- Oxygen:Below the optimal temperature, enzymes and substrates have less kinetic energy so there are fewer reaction-inducing collisions.
Above the optimal temperature, enzymes begin to denature
- Enzyme inhibition:Inhibitors can slow down the rate of reaction
Noncompetitive inhibitors bind to the allosteric site, changing the shape of the active site so no substrate can bind.
The effect of competitive inhibitors can be overcome if the substrate concentration is increased.
what biofuels are and how they are made to replacenon-renewable resources andexamples of biofeuls
Biofuels are a renewable source of energy which come from organic material called biomass. These are plant and animal materials and offer an alternative to fossil fuels (gas, coal) which is non-renewable.
Examples of biofuels: bioethanol, biodiesel, biogas.
what are fossil fuels
Fossil fuels are fossilised plant and animal products that take millions of years to produce. This is slowly running out due to high energy consumptions.
process of producing bioethnaol
Step 1: Deconstruction
Biomass is broken down to increase surface area to make fermentation efficient
Cell wall and cellulose is broken down. Approaches include the use of chemicals, mashing and grinding, heating.
Step 2: Digestion by enzymes
Broken down biomass is then exposed to enzymes to convert starch into glucose and other sugars.
The cell wall and cellulose is broken down via chemical/biological/physical/physio-chemical processes in order to help the biomass increase its surface area enough to make the fermentation process more efficient
The broken down biomass is then exposed to enzymes which will break down the starch and cellulose into glucose and other sugars and is aided by the presence of water (process is known as hydrolysis)
Yeast is used to facilitate the anaerobic fermentation of sugars and a large amount of ethanol diffuses out of the yeast cells and is harnessed by biofuel
The ethanol is distilled converting it into biofuel. The biofuel is then purified and ready to be used as a liquid fuel
Implications of biofuels
strenghts;
produced carbob emission
provides altneraitve to fosisl fuels whihc will one day run out
Reduced reliance from ils from other coutnries
weaknes:
large amounts of cropped are proudecd, places strain on agriculture
expensvie compared to traiditonal fuels
no compatiable with all energy systems
largeer second order enviornmenal impactssuch as deforestation,
compare amoutn of ATP produced in aerobic vs anaeorbic cellular respraiton
aerobic cellular respraiton produces 30 or 32 ATP, whilst anaeorbic cellular respriation prodcues 2 ATP.
whats acetyl-coA
examples of enzymes in cellular repsiraiton
- pruvate kinase- catalayses the final step in glycolsuis to produce pryuvate and make ATP
- citrate sythnase-first enzyme in the krebs cycle that allows for the reycleing of actyl-coa
- chrochrome c oxidase-
key enzyme of etc taht attahces H+ and e- to oxygne to proce water
wha ti sthe link reaciton
biofuels are produced froma
anaerobic fermnration of biomass
