Respiration Flashcards
What is Aerobic Respiration?
Complete breakdown of glucose and requires oxygen as the final electron acceptor.
Why is respiration described as a catabolic process?
Complex molecules are broken down into smaller simpler molecules.
Why do organisms need to respire?
Releases energy to produce ATP for a variety of processes.
Four stages of aerobic respiration and where they occur?
Glycolysis - cytosol
Link Reaction - Mitochondrial Matrix
Krebs Cycle - Mitochondrial Matrix
ETC - Inner M Membrane
Outline the stages of glycolysis
Glucose phosphorylated to hexose phosphate by 2X ATP
Hexose phosphate splits into 2X triers phosphate
2 molecules of TP oxidised to 2X pyruvate
What is the function of Krebs Cycle?
Releasign energy from C bonds to provide ATP, NADH2 and FADH2.
Outline Link Reaction
Oxidative decarboxylation and dehydrogenation of pyruvate to form acetate
Net gain of CO2 and 2x NADH2
Acetate combines with coenzyme A to form acetyl coenzyme A
Role of RED NAD AND FAD
They are a source of electrons and protons
How does chemiosmosis produce ATP during aerobic respiration?
Protons flow down their conc gradient from the intermembrane space into the MM via ATP synthase
ATP S phosphorylates ADP to form ATP as protons flow through it
Why is O important as FEA in the ETC
Removes e and p from matrix to prvent accumulation. ( NO p Grad,ATP S cant function, ATP not produced and cell die)
Per turn of Krebs Cycle how much of each product is produced?
3 CO2
3 Red NAD
1 Red FAD
Define Aerobic Respiration
A form of cellular respiration that takes place in the absence of oxygen.
Product of anaerobic respiration in animals
Lactate
Outline Anaerobic respiration in animals:
Only Glycolysis continues RED NAD (from G) transfer H to pyruvate ,forming lactate
Product anaerobic respiration in plants and fungi
Ethanol and CO2
Outline Anaerobic respiration in plants and fungi
Only Glycolysis continues
Pyruvate is decarboxylated to form Ethanal
Ethanal is reduced to Ethanol using RED NAD producing Oxidised NAD for further G
Why is the maximum yield of ATP in aerobic respiration never achieved?
ATP lost due to leaky membranes
Energy required to move pyruvate and ADP into the mitochondrial Matrix
Name two types of molecules that can be used as alternative respiratory substrates?
AAs from Proteins
Glycerols and Fatty Acids from lipids
Explain how lipids are used in respiration
Hydrolysed to G and FA
G converted to 3C sugar and enters glycolysis
FA broken down into 2C acetate fragments which enter as acetyle coenzyme A in KC
Explain how proteins are used in respiration
Hydolysed to AAs
AAs deaminated in the liver forming keto acids and ammonia
Keto acids enter G and KC
Explain how proteins are used in respiration
Hydrolysed to AAs
AAs deaminated in the liver forming keto acids and ammonia
Keto acids enter G and KC
What happens at the start of glycolysis?
Phosphorylation
Net gain of ATP for G
2 (4 made 2 used)
Where does NAD carry H to next in G?
ETC
Where does dehydrogenase act in g?
Between triose phosphate and pyruvate.
What enzymes are involved in link reaction?
Dehydrogenase and Decarboxylase
