Respiration
- Created by: Labake
- Created on: 14-10-14 10:16
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- Respiration
- Why do living organisms respire?
- Potential chemical energy in large organic molecules
- Kinetic energy in moving molecules
- Reactions that take place in organisms and require energy are metabolic
- E.g. Active transport, Secretion, Endocytosis, Synthesis of large molecules, Replication of DNA and synthesis of organelles, Movement (muscle contraction).
- Energy comes from sunlight for photoautotrophs- making large organic molecule that have chemical potential energy-Respiration used to release this energy and its stored in ATP when ADP is phosphorylated
- ATP is Adenosine Triphosphate- 30kJ of energy made/released- found in prokaryotic and eukaryotic cells- made by ATP synthase, split by ATPase
- Coenzymes
- Dehydrogenase enzymes needed in Glycolysis, Link and Krebs
- Coenzymes needed to help catalyse oxidation and reduction reactions
- E.g. NAD combines with H atoms to inner mitochondrial membranes for oxidative phosphorylation
- Combine = reducedNAD, release= oxidisedNAD (just NAD)
- Nicotinamide Adenine Dinucleotide
- E.g. Coenzyme A combines with Acetate (Acetyl CoA) for link to Krebs
- Coenzyme A also combines with Acetate from Fatty Acids (B-oxidation) to Krebs Cycle
- E.g. NAD combines with H atoms to inner mitochondrial membranes for oxidative phosphorylation
- Glycolysis
- Occurs in the cytoplasm of all cells (prokar and erukar)
- STAGE 1: Glucose phosphorylated to Fructose-1-phosphate (activated)
- ATP is hydrolysed to release phosphate
- STAGE 1: Fructose-1-phosphate phosphorylated to Hexose Bisphosphate
- ATP is hydrolysed to release phosphate
- STAGE 2: Hexose Bisphosphate split into 2x Triose Phosphate
- STAGE 3: Triose phosphate molecules oxidised (x2 hydrogen atoms removed) by NAD
- 2x ATP molecules made when TP is phosphorylated (substrate level phosphorylation)
- NAD to redNAD using dehydrogenase enzymes
- STAGE 4: Intermediate product (3C) converted to x2 Pyruvate
- x2 ADP phosphorylated to ATP (substrate level phosphorylation)
- The Link Reaction and Krebs Cycle
- Pyruvate dehydrogenated and decarboxylated to Acetate
- Acetate reacts with Coenzyme A to Acetyl CoA
- Acetate (2C) reacts with Oxyloacetate (4C) maing Citrate (6C)
- Citrate dehydrogenated and decarboxylated to (5C)
- Makes CO2 and redNAD
- (5C) decarboxylated and dehydrogenated to (4C)
- Makes CO2 and redNAD
- (4C) to another (4C) phosphate released by hydrolysis
- ADP phosphorylated to ATP
- (4C) to another (4C) releasing x2 H atoms
- FAD reduced to redFAD
- (4C) to Oxyloacetate
- Acetate reacts with Coenzyme A to Acetyl CoA
- Acetate (2C) reacts with Oxyloacetate (4C) maing Citrate (6C)
- Citrate dehydrogenated and decarboxylated to (5C)
- Makes CO2 and redNAD
- (5C) decarboxylated and dehydrogenated to (4C)
- Makes CO2 and redNAD
- (4C) to another (4C) phosphate released by hydrolysis
- ADP phosphorylated to ATP
- (4C) to another (4C) releasing x2 H atoms
- FAD reduced to redFAD
- (4C) to Oxyloacetate
- NAD reduced to redNAD
- Citrate dehydrogenated and decarboxylated to (5C)
- Acetate (2C) reacts with Oxyloacetate (4C) maing Citrate (6C)
- NAD reduced to redNAD
- Acetate reacts with Coenzyme A to Acetyl CoA
- Citrate dehydrogenated and decarboxylated to (5C)
- Acetate (2C) reacts with Oxyloacetate (4C) maing Citrate (6C)
- Two turns for 1 glucose molecule
- Structure and function of mitochondria
- 0.5 to 1.0 micrometres in diameter and 2 to 5 micrometres long
- INNER MEMBRANE: Phospholipid- impermeable to most small ions
- INNER MEMBRANE: Has ATP synthase and electron carriers embedded
- Electron carriers in ETC,s and are enzymes with cofactors that can accept and donate electrons
- ATP synthase- protrudes from inner membrane to matrix and protons flow through down conc. gradient (chemiosmosis)
- Protons accumulate in the intermembrane space and build up a proton gradient
- INNER MEMBRANE: Has ATP synthase and electron carriers embedded
- OUTER MEMBRANE: Has protein carriers, channels and enzymes
- MATRIX: Has enzymes for Link and Krebs, NAD, oxyloacetate, mito ribosomes and mito DNA (code for enzymes named)
- Oxidative Phosphorylation and Chemiosmosis
- Occurs on the inner mitochondrial membrane
- Formation of ATP by adding phosphate to ADP in presence of O2 (final e- acceptor)
- Electron carriers and ATPsynthase embedded in membrane
- redNAD and redFAD reoxidised- H atoms released and split into H+ and e-
- e- accepted by electron carrier and passed along electron transport chain
- 4e- in ETC and 4H+ are accepted by O2 and produce 2H2O
- H+ stay in matrix solution
- As e- flows along ETC, energy released used by electron carriers to pump H+ into intermemebrane space
- Oxidative Phosphorylation and Chemiosmosis
- Occurs on the inner mitochondrial membrane
- Formation of ATP by adding phosphate to ADP in presence of O2 (final e- acceptor)
- Electron carriers and ATPsynthase embedded in membrane
- redNAD and redFAD reoxidised- H atoms released and split into H+ and e-
- e- accepted by electron carrier and passed along electron transport chain
- 4e- in ETC and 4H+ are accepted by O2 and produce 2H2O
- H+ stay in matrix solution
- As e- flows along ETC, energy released used by electron carriers to pump H+ into intermemebrane space
- As e- flows along ETC, energy released used by electron carriers to pump H+ into intermemebrane space
- e- accepted by electron carrier and passed along electron transport chain
- redNAD and redFAD reoxidised- H atoms released and split into H+ and e-
- H+ flow back into matrix through ATPsynthase, driving rotation part of the enzyme
- Enzyme phosphorylates ADP and produces ATP
- Enzyme phosphorylates ADP and produces ATP
- Oxidative Phosphorylation and Chemiosmosis
- As e- flows along ETC, energy released used by electron carriers to pump H+ into intermemebrane space
- e- accepted by electron carrier and passed along electron transport chain
- redNAD and redFAD reoxidised- H atoms released and split into H+ and e-
- H+ flow back into matrix through ATPsynthase, driving rotation part of the enzyme
- Enzyme phosphorylates ADP and produces ATP
- Enzyme phosphorylates ADP and produces ATP
- Evidence for Chemiosmosis
- Visual proof of cristae
- Proof that chemiosmosis provides energy to produce ATP
- Research proves need of certain enzymes and the need for the intermembrane space (outer membrane removed = no ATP)
- pH of IMS lower than matrix + and potential difference more neg in matrix
- Anaerobic respiration in mammals and yeast
- Release of energy from substrates without oxygen- only uses Glycolysis
- redNAD has to be reoxised (recycled) for glycolysis to continue
- Lactate fermentation
- In mammals during vigorous activity
- Pyruvate is H+ acceptor (from redNAD)
- Becomes Lactate using Lactate dehydrogenase
- Carried in the blood to the liver- back to pyruvate/glucose when O2 present
- Reduction in pH lowers enzyme activity= muscle fatigue
- Carried in the blood to the liver- back to pyruvate/glucose when O2 present
- Becomes Lactate using Lactate dehydrogenase
- redNAD to NAD can now accept more H+ from TP
- Pyruvate is H+ acceptor (from redNAD)
- Becomes Lactate using Lactate dehydrogenase
- Carried in the blood to the liver- back to pyruvate/glucose when O2 present
- Reduction in pH lowers enzyme activity= muscle fatigue
- Carried in the blood to the liver- back to pyruvate/glucose when O2 present
- Becomes Lactate using Lactate dehydrogenase
- Pyruvate is H+ acceptor (from redNAD)
- Ethanol fermentation
- In fungi e.g. yeast cells
- Pyruvate molecule loses CO2 (decarboxylase) making Ethanal
- Ethanal accepts H atoms from redNAD- reduces to Ethanol
- redNAD reoxidised to NAD
- Ethanal accepts H atoms from redNAD- reduces to Ethanol
- Lactate fermentation
- Respiratory Substrates
- A organic substance that can be used for respiration (aerobic)
- The more H+ in a substrate, the more ATP produced and the more O2 needed
- Lipids- Fatty adcids combine with CoA and taken to mito matrix
- Split into Acetyl CoA- B-oxidation makes redNAD and redFAD
- Proteins- When lack of substrates, can be hydrolysed to amino acids
- Converted to Pyruvate, Acetate etc
- Carbs- Mostly glucose, other monosaccharides broken down into glucose
- the process whereby energy stored in complex organic molecules is used to make ATP
- Why do living organisms respire?
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