Respiration Flashcards
What are the two types of respiration?
Aerobic and anaerobic
What is the difference between aerobic and anaerobic?
Aerobic- Oxygen
Anaerobic- No oxygen
What is the word equation for aerobic respiration?
Oxygen + glucose-> Carbon dioxide + water
What is the overall word equation for anaerobic respiration?
Glucose -> Lactate/ ethanol + carbon dioxide
How much ATP is created in both respirations?
38
2 in anaerobic
What are the four stages of aerobic respiration?
Glycolysis
Link reaction
Krebs cycle
Oxidative phosphorylation
Where does aerobic respiration take place?
Glycolysis in the cytoplasm.
Link reaction and Krebs cycle in the matrix.
Oxidative phosphorylation in the cristae membrane.
Where does anaerobic respiration take place?
Cytoplasm
What are the stages of anaerobic respiration?
Glycolysis and fermentation
What are the end products of aerobic respiration?
Carbon dioxide and water
What are the end products in anaerobic respiration?
Lactate in animals and ethanol in plants
What stage of respiration is present in both respirations?
Glycolysis
What is the overview of glycolysis?
6C molecule is split into two 3C pyruvate molecules
What is the overview of the link reaction?
3C pyruvate molecules undergo a series of reactions to form acetyl coenzyme A, 2C.
What is the overview of the Krebs cycle?
A cycle of oxidation and reduction reactions. AcetylCoenzyme A enters. ATP and NADH and FADH are produced
What is the overview of oxidative phosphorylation?
NADH and FADH produced in the Krebs cycle, release their electrons to synthesise ATP. Water is a by product
What are the 4 stages of glycolysis?
- Phosphorylation of glucose to glucose phosphate
- Splitting of phosphorylated glucose
- Oxidation of triose phosphate
- Production of ATP
How does phosphorylation occur in glycolysis ?
Two ATP molecules are hydrolysed to ADP. Their phosphate molecules bind to glucose
Why is glucose phosphorylated during glycolysis?
Lowers the activation energy for enzyme controlled reactions
When glucose is split during glycolysis, what is created?
Two molecules of triose phosphate (3C)
How is triose phosphate created?
Glucose phosphate splits to become two molecules of triose phosphate
How is triose phosphate converted into pyruvate?
Hydrogen molecule is removed from the triose phosphate by NAD to make NADH. 2 molecules of ADP reacts with triose phosphate to become 2 molecules of ATP leaving pyruvate
How is triose phosphate oxidised during glycolysis?
Hydrogen is removed from the triose phosphate which is transferred to NADH.
What is a coenzyme?
Non protein molecule which binds loosely to an enzyme to help catalyse reactions
How many ATP molecules are generated during glycolysis?
4 but the net production is 2
How much NADH is generated during glycolysis?
2
How many molecules of pyruvate is generated during glycolysis?
2
What is the net output of glycolysis?
2 ATP, 2 pyruvate, 2 NADH
What is NAD
A hydrogen carrying molecule, when reduced can carry energy to another stage of respiration
In anaerobic respiration what happens to pyruvate?
Converted to ethanol in plants and lactate in animals
In aerobic respiration, what happens to pyruvate?
Actively transports into the mitochondrial matrix to for the link reaction.
Why does the link reaction occur?
Pyruvate stores energy which is released during the Krebs cycle but it must be oxidised first
What happens to the pyruvate in the link reaction?
It is oxidised into Acetate which combines with CoA to produce acetylCoA
Suggest why pyruvate can enter the mitochondria and glucose cannot.
Pyruvate is smaller
What does pyruvate form when it is oxidised during the link reaction?
Oxidised to acetate
What is the overall equation for the link reaction?
Pyruvate + NAD +CoA -> Acetyl CoA + NADH +CO2
What does the link reaction produce?
Cycle happens twice per pyruvate so 2 NADH, 2 acetylCoA and 2 CO2
What type of phosphorylation occurs in the Krebs cycle?
Substrate level phosphorylation
What is produced in a single Krebs cycle?
3 NADH
1 FADH
1 ATP
2 CO2
At the end of the link reaction and the Krebs cycle, what is produced per molecule of pyruvate?
4 NADH
1 FADH
1 ATP
3 CO2
At the end of the Krebs cycle, what is produced per molecule of glucose?
10 NADH
2 FADH
4 ATP
6 CO2
Why is NAD so important in respiration?
Acts with dehydrogenase enzymes to catalyse the removal of hydrogen atoms and their transfer to molecules used in oxidative phosphorylation providing energy.
What molecules are brought from the Krebs cycle to oxidative phosphorylation?
NADH and FADH
What are reduced NAD and reduced FADH required for in oxidative phosphorylation?
When reduced, they carry hydrogen atoms. The electrons these atoms possess are a source of energy used for the formation of ATP
What does the matrix of a mitochondria contain?
Proteins, lipids, DNA
What does the cristae contain?
Enzymes and other proteins involved in oxidative phosphorylation
Where would you find cells with the most mitochondria?
Metabolically active cells, such as muscle cells or epithelial cells which carry out active transport
How are mitochondria different in metabolically active cells?
Have more densly packed cristae so more SA of membrane for more enzymes and proteins for oxidative phosphorylation
What is the electron transport chain?
Series of electron carrier molecules found in the cristae of the mitochondria and allow oxidative phosphorylation
What is the purpose of oxidative transfer chain?
Production of ATP using the energy released from electrons carried by NADH and FADH
Give an overview of oxidative phosphorylation
Hydrogen atoms are combined with NAD and FAD to reduce them. NADH and FADH donate the electron from the hydrogen atom to the ETC. The electrons move through the chain, releasing energy for the transport of protons into the inner membrane space. The protons move back by diffusion through ATP synthase channels.
What happens to the protons and electrons at the end of oxidative phosphorylation?
Combine with oxygen to form water
What is the final electron acceptor in the ETC?
Oxygen
Why is it important that oxygen has its role in respiration?
Accepts the hydrogen atoms produced during glycolysis and the Krebs cycle. If it didnt do this, the protons and electrons would back up along the chain and the process would stop
Why isnt the energy carried by electrons in oxidative phosphorylation released in one go?
Most would be released as heat
What allows the energy to be released slowly during oxidative phosphorylation?
Released in stages throughout the ETC as they are passed from carrier to carrier
