Respiration Ch.12 Flashcards
Name the four stages of aerobic respiration
1) Glycolysis
2) The Link reaction
3) The Krebs/ citric acid cycle
4) Oxidative phosphorylation/ The Electron Transfer Chain
the overall reaction for aerobic respiration
glucose(C6H12O6) + 6O2 = ATP + 6H20 + 6CO2
Where does Glycolysis take place?
Cytoplasm
What is the reactant and the end product in Glycolysis
Starts with 6-Carbon glucose and produces two 3-carbon pyruvate molecules.
Name everything that’s produced in Glycolysis
2 pyruvates, 2NADH, 4ATP, 2ADP
What happens during Glycolysis?
1) Glucose gets phosphprylated by two ATP (ATP goes to ATD+Pi) and forms fructose-1,6-biphosphate.
4) Gets broken into two Triose phosophate
5) For each Triose phosphate, a NAD is reduced to NADH and 2ADP is converted into 2ATP.
6) Overall two pyruvates/ pyruvic acid are produced.
Why is the net production of ATP in Glycolysis 2?
2 ATP’s are needed and four ATP’s are produced therefore there is only a gain of 2 ATP’s.
Name everything that’s needed for glycoysis
Glucose, 2ATP, 4ADP + 4Pi, 2NAD
How many ATP’s are produced by glycolysis?
2 ATPs
How many ATP’s are produce by ETC
34 ATPs
What is substrate level phosphorylation and where does it occur?
The synthesis of ATP by reorganising chemical compounds. Occurs in glycolysis and the Krebs Cycle (cytoplasm and matrix)
What is oxidative phosphorylation and where does it occur?
The synthesis of ATP using an electrochemical gradient from the build up of H+ ions on one side of the mitochondria. Occurs in the Electron Chain Cycle (across the inner mitochondial membrane and thylakoid)
How many ATP’s can one NADH yied?
3
How many ATP’s can one FADH yield?
2
What stage of respiration can occur in aerobic conditions?
Glycolysis
What is a Coenzyme?
A non-protein molecule that binds with a specific enzyme or substrate. They cannot themselves catalyse a reaction but they help enzymes to catalyse a reaction.
Name all the Coenzymes used in respiration
NAD, FAD and CoA (coenzyme A)
What happens in The Link Reaction
Pyruvate is dehydrogenated, decarboxylated to acetly, (reducing NAD to NADH and producing CO2)). Acetly then combines with CoA to produce AcetlyCoA.
Per glucose what and how many products are made in the link reaction.
2xCO2, 2xNADH and 2xAcetylCoA
Where does the Link Reaction take place?
In the mitochondrial membrane
Where does the Krebs Cycle take place?
In the mitochondrial membrane
What happens in the Krebs cycle
1) CoA and acetyl un-combine. Acetyl(2C) joins with a 4C to form a 6C.
2) 6C is decarboxylated and dehydrogenated producing CO2, reducing NAD to NADH and a 5C
3) 5C is decarboxylated and dehydrogenated producing CO2, reducing NAD to NADH and producing an ATP and a 4C.
4) 4C is dehydrogenated, reducing FAD to FADH and NAD to NADH.
5) The 4C is regenerated and the cycle can occur again.
How many ATPs are produced in the Krebs cycle per glucose? And how?
2ATP produced from Substrate Level phosphorylation.
18 ATP from NADH, and 4ATP from FADH from Oxidative phosphorylation.
From one molecule of Glucose, how many ATPs are made?
38
What are the roles of NAD and FAD?
To carry H atoms from glycolysis, the link cycle and the Krebs cycle into the electron transport chain.
Where does the Electron Transfer Chain occur
Across the inner mitochondrial membrane
What is Chemiosmosis
The diffusion of Hydrogen ions across a selectively permeable membrane, down a solute potential gradient.
Give three important molecules in the inner mitochondrial membrane
Protein channel, carrier protein and ATP synthase.
Where do the H+ come from?
From the glucose (can be from lipids or proteins). It is transported by the coenzyme NAD.
How does the H+ move out of the matrix?
The H+ is pumped by active transport through the protein channel, using the energy from moving electrons.
How do the electrons produce energy?
Electrons move along carrier proteins reducing them as they go along releasing energy.
Why is Oxygen required in respiration?
Electrons bind to the oxygen molecule, which splits and combines with H+. Producing H2O.
How is ATP synthesised in the Electron Transport Chain?
H+ move down the electrochemical gradient back into the matrix through ATP synthase. This causes a change in conformation of the ATP synthase cataylsing ADP + Pi to ATP.
Why isn’t the ATP production 100% efficient?
1) Protons leak across the mitochondrial membrane so no longer available to generate ATP.
2) ATP is used to move pyruvate and NADH to the mitochondria.
3) Energy is lost as heat in order to maintain body temperature.
What determines the energy value of a molecule?
The number of Hydrogens. More hydrogen = more reduction of coenzymes = more NADH and FADH which produces more ATP from the ETC.
How can Lipids be used in respiration?
Lipids are hydrolysed into 3 fatty acids and glycerol. Fatty Acids are changed into acetyl CoAand enter the Krebs cycle. Glycerol is phosphorylated into Triose Phosphate and enters glycolysis.
When are proteins used for respiration?
Only when there is no Lipids and carbohydrates and only proteins remain. E.g in starvation
How are proteins used in respiration?
Proteins are hydroysed to amino acids and then deaminated in the liver. Urea is secreted. Pyruvate (3C) is produced and 5C, 6C in the Krebs cycle.
What’s the equation for anaerobic respiration in yeast and plant?
Glucose = ethanol + CO2 + energy
What’s the equation for anaerobic respiration in animals?
Glucose = lactic acid + energy
What happens in anaerobic respiration?
Glucose turns to pyruvate, Producing two ATP and two NADH. Pyruvate turns into two lactate reducing NADH, to be used again
What happens in anaerobic respiration
Glucose turns into pyruvate producing 2ATP and 2NADH. Pyruvate turns into 2CO2 and 2ethanol.
Why does anaerobic respiration produce less ATP
Only goes through glycolysis so can only have substrate level phosphorylation
Why is anaerobic respiration important
Produces some ATP, regenerates NAD, allows glycolysis to continue and prevents end-product inhibiton.
Give some evidence that proves chemiosmosis
1) Can measure the pH which measure the H+ from the proton gradient.
2) ATP synthase can still produce ATP even when no electron transport is occurring, as it is using the electrogradient.
3) Chemicals that stop ETC and the gradient prevent ATP synthase.
What does ATP stand for?
Adenosine Triphosphate
What is the structure of ATP
Has adenine, a ribose sugar ad three phosphate groups.
How is energy released from ATP
When the bond between phosphate group breaks, energy is released.
Why is ATP a good source of energy
The bonds between phosphate are unstable and have low activation energy, therefore the bonds are easily broken.
Give the roles of ATP
1) Active transport
2) Phosphorylation (gycolysis)
3) Muscle contraction
4) Secretion of cell products (lysosomes)
Name a step in aerobic respiration in which carbon dioxide is produced?
The Krebs cycle
What does NADH do in anaerobic respiration?
The hydrogen from NADH is used to turn pyruvic acid into ethanol
Explain why the rate of carbon dioxide production is higher in a nitrogen environment than in air.
-In nitrogen environment respiring anaerobically;
- which produces less ATP
- More anaerobic respiration must occur to produce the same amount of ATP, so more carbon dioxide
produced.
Where does anearobic respiration occur?
In the cytoplasm
What properties of ATP make it suitable to be an energy source?
- Energy released in small/suitable amounts;
- Soluble;
- Involves a single/simple reaction;
Why do humans need to produce large amounts of ATP?
- ATP is unstable
- ATP cannot be stored
- Used for muscle contractions
- ATP only releases a small amount of energy at
a time
At the end of a sprint race why will a runner continue to breath rapidly?
As lactic acid builds up due to anaerobic respiration. Oxygen breaks down lactic acid
