Module 4- Respiration Flashcards
Why do plants, animals and microorganisms need to respire?
The sum of all chemical processes that occur in living organisms is known as the metabolism. All chemical processes require energy to drive them.
What biological processes require energy?
Active Transport Endocytosis Secretion Activation of chemicals Movement
What are the different structures inside a mitochondria?
Inter-membrane space Envelope-(inner and outer membrane) Matrix Cristae Stalked particles( ATP synthase)
What happens in the matrix?
The matrix is where the Kreb’s cycle and the link reaction take place.
It contains enzymes required to catalyse these stages.
It also contains molecules of the coenzyme NAD and oxaloacetate.
DNA and ribosomes
What are the stages of aerobic respiration?
Glycolysis
Formation of acetyl coenzyme
Kreb’s cycle
Electron transport and chemiosmosis
What stage of respiration occurs in the cytoplasm?
Glycolysis
What stage of respiration occurs in the cristae?
Electron transport and chemiosmosis
What types of anaerobic respiration are there?
Ethanol and lactate fermentation
What is the process of lactate fermentation?
- In lactate fermentation, pyruvate molecules from glycolysis act as hydrogen acceptors.
- They accept hydrogen atoms from the NADH to form NAD .
- This process is catalysed by the enzyme lactate dehydrogenase.
- NAD is now re-oxidised and is available to accept more hydrogen atoms from glucose.
- Glycolysis can continue to produce a net gain of two ATP molecules.
What is the process of ethanol fermentation?
- In ethanol fermentation, each molecule of pyruvate is decarboxylated to produce CO2.
- This is catalysed by the enzyme pyruvate decarboxylase.
- This forms a molecule of ethanal.
- Ethanal is a hydrogen acceptor and accepts 2H+ from NADH, forming NAD.
- This is catalysed by the enzyme ethanol dehydrogenase.
- The NAD has been re-oxidised.
What do coenzymes do?
Needed to help these enzymes carry out the oxidation and reduction reactions of aerobic respiration.
Why are coenzymes important for aerobic respiration?
Enzymes are not very good at catalysing redox reactions.
What are the four stages of aerobic respiration?
- Glycolysis
- Link reaction
- Kreb’s cycle
- Oxidative phosphorylation
List in order the intermediate compounds made in glycolysis from glucose to pyruvate.
Glucose-6-P Fructose-1-P Hexose-1,6-biphosphate Triose phosphate Pyretic acid
What are the products of glycolysis?
2ATP
2NADH
Pyruvate
Where does the link reaction take place?
Mitochondrial matrix.
What two enzymes are used in the first part of the link reaction?
Pyruvate decarboxylase
Pyruvate dehydrogenase
What are the products of the link reaction?
2x Acetyl CoA
2x CO2 released
2x NADH
How is acetate transported to the Kreb’s cycle?
Combines with coenzyme A to produce acetyl CoA
What are the different compounds in the Kreb’s cycle in order?
Acetate Citrate (6C) 5C 4C 4C 4C Oxaloacetate
When does decarboxylation and dehydrogenation happen in the Kreb’s cycle?
Citrate to 5C compound. 5C to 4C.
CO2 and NADH are produced.
What is chemiosmosis?
The use of energy in a chemical gradient to generate ATP by the flow of H+ ions through ATP synthase.
What is respiratory rate?
The rate at which organisms convert glucose to CO2 and water. It can be calculated by measuring an organism’s rate of oxygen consumption using a respirometer.
What is a respiratory substrate?
Organic molecule that can be broken and used for respiration. Examples include carbohydrates, protein and lipids.
Why can lipids make more energy?
High number of H+
More reduced NAD
More H+ delivered to the interment and space.
More ATP molecules made by chemiosmosis
