Biology Unit 3.3 - Respiration & Glycolysis Flashcards
What is glycolysis?
Splitting of sugar that occurs in the cytoplasm, which doesn’t require oxygen, and produces ATP through SLP
What occurs during stage 1 of glycolysis?
Glucose is phosphorylated forming hexose phosphate, which splits into triose phosphate
What occurs during stage 2 of glycolysis?
Triose phosphate is oxidised forming pyruvate, through dehydrogenation
NAD collects the hydrogen ions forming reduced NAD
2 ATP produced through SLP
What occurs during the link reaction?
Pyruvate is converted into acetate through decarboxylation, which combines with coenzyme A to form acetyl CoA
What occurs during the Krebs cycle?
Takes place in the mitochondrial matrix, where acetate combines with a 4C molecule to form a 6C molecule
Series of decarboxylation and dehydrogenation forms a 4C molecule from the 6C molecule
NAD and FAD are reduced and carry electrons and protons to the electron transport chain
What is the function of 2 CoA?
Are regenerated and returns to the link reaction
What is the function of 2 4C molecules?
Are regenerated to allow the Krebs cycle to continue
What is the function of 4 CO2?
Waste product that diffuses out of the cell
What is the function of 2 ATP?
Produced by SLP
What is the function of 6 reduced NAD and 2 reduced FAD?
Pass to the inner membrane of the mitochondria and donate electrons and protons to the electron transport chain
How are FAD and NAD similar?
Both contain a pentose sugar
Both have two phosphate groups
Both contain two nitrogenous bases
They are both nucleotides
How are FAD and NAD different?
FAD has one ring sugar - NAD has two ring sugars
FAD has one linear and one ring 5C sugar - NAD has two ring 5C sugars
FAD contains flavin - NAD contains nicotinamide
FAD has a three-ring base - NAD has a one ring base
What occurs in the electron transport chain?
Excited electron pass along electron carriers, providing electron energy which drives proton pumps
Hydrogen ions are pumped into the inter membrane space via a proton pump mechanism
Hydrogen ions diffuse back into the matrix through stalked particles attached to ATP synthetase
Electrochemical gradient generated provides needed energy for ATP production
Process is known as chemiosmosis
What is the role of oxygen in the electron transport chain?
Combines with hydrogen to form water, ensuring the flow of electron energy is maintained
How is ATP production in chloroplasts and mitochondria similar?
Involve transport of excited electron from carrier to carrier
Electron energy is released to drive proton pumps
Protons are pumped into the inter membrane space
Protons diffuse down the concentration gradient through stalked particles
Electrochemical gradient provides the energy needed to produce ATP
ATP is produced from ADP and Pi by chemiosmosis
How is ATP production in chloroplasts and mitochondria different?
No SLP - SLP present
Electron originate from chlorophyll and water - Electron originate from H atoms
Electrons either return to chlorophyll or are passed to NADP - Oxygen is the final electron acceptor
Chemiosmosis occurs on thylakoid membranes - Chemiosmosis occurs on the inner membrane
H ions accumulate in the thylakoid cavity - H ions accumulate in the inter membrane space
Only 1 proton pump - 3 types of proton pumps
What occurs during anaerobic respiration?
Absence of oxygen means reduced NAD and FAD cannot be re-oxidised, so the link reaction and Krebs cycle cannot take place
ATP yield is reduced - 2 molecules
Why is oxygen important in ATP production?
Hydrogen atoms combine with oxygen to form water
Without oxygen, hydrogen atoms accumulate, and the process stops
How is lactic acid formed in animal cells?
Reduced NAD passes hydrogen to pyruvate, reducing it to lactate
Yields two molecules of ATP
Lactic acid builds up causing cramps
When oxygen is available lactic acid is broken down and converted into glycogen
What occurs during fermentation in yeast?
Pyruvate is decarboxylated to produce ethanal
Hydrogen is released and passed on to NAD
Reduced NAD passes the hydrogen to ethanal, reducing it to ethanol
Yields 2 molecules of ATP
How is fat used in respiration?
Used when carbohydrate levels are low
Split into glycerol and fatty acids by hydrolysis
Glycerol is converted into a 3C sugar and enters the Krebs cycle via triose phosphate
Long fatty acid chains are split into 2C molecule and enter as acetyl CoA
Large number of ATP molecules are built up
H ions released are picked up by NAD and fed into the electron transport chain
How is protein used in respiration?
Used during starvation
Hydrolysed into its constituent amino acids
Amino acids are deaminated in the liver
Amino groups is converted into urea and excreted
Rest of amino acids are converted into acetyl CoA, pyruvate or some other Krebs cycle intermediate
How do electrons move from cytochrome to cytochrome?
Cytochromes have complimentary shapes and bind
Cytochrome c receives an electron, changing its tertiary shape
Cytochrome c is now complimentary to cytochrome oxidase
Electron is passed to oxygen, where cytochrome c detaches and returns to cytochrome bc
What are the main products of glycolysis?
2 ATP
2 Reduced NAD
2 Pyruvate
What are the main products of the Krebs cycle?
2 CoA
2 4C molecules
4 CO2
2 ATP
6 Reduced NAD
2 Reduced FAD
What are the main products of the electron transport chain?
ATP
Water
Oxidised NAD
Oxidised FAD
