Respiration Flashcards
(11 cards)
What are the two types of respiration?
Aerobic and anaerobic respiration.
What is the importance of respiration?
Respiration produces ATP.
What are the key stages of aerobic respiration and where do each of them take place?
1) Glycolysis (cytoplasm)
2) Link reaction (mitochondrial matrix)
3) Krebs cycle (mitochondrial matrix)
4) Oxidative phosphorylation (inner mitochondrial membrane)
What happens during glycolysis?
Glucose is phosphorylated to glucose phosphate , using ATP. This produces TP which is then oxidised to produce pyruvate with a net gain of ATP and NADH. Pyruvate and NADH are actively transported from the cytoplasm into the mitochondrial matrix.
What are the products of glycolysis?
2 pyruvate, net gain of 2 ATP, and 2 NADH.
What happens during the link reaction?
The pyruvate made in glycolysis is oxidised to acetate. NAD picks up the hydrogen and becomes NADH. Acetate then combines with coenzyme A to produce acetylcoenzyme A.
What are the products of the link reaction?
2 CO2, 2 AcetylCoA, 2 NADH.
What happens during the Krebs cycle?
Acetyl-CoA reacts with a 4 carbon molecule, releasing coenzyme A and producing a 6 carbon molecule that enters the Krebs cycle. In a series of redox reactions, the krebs cycle generates reduced coenzymes and ATP by substrate-level phosphorylation, and CO2 is lost.
What are the products of the Krebs cycle?
Per cycle: 3 NADH, 1 FADH, 1 ATP, and 2 CO2 but products are doubled for every glucose molecule as there are two cycles for every glucose molecule.
What happens during oxidative phosphorylation?
Hydrogen atoms from NADH and FADH from the Krebs cycle split into protons and electrons. These electrons enter the ETC and energy is released as they pass between electron carriers which actively transports protons across the inner mitochondrial membrane from the matrix into the intermembrane space. The protons move down their concentration gradient back to the matrix by facilitated diffusion via proton channels. ATP synthase catalyses the formation of ATP from ADP and Pi.
What happens during anaerobic respiration and why?
Respiration occurs anaerobically in the absence of oxygen in the cytoplasm. Anaerobic respiration is only glycolysis. The pyruvate produced in glycolysis is reduced to form ethanol and CO2 (in plants and microbes) or lactate (in animals) by gaining the hydrogen from NADH. This oxidises NAD so that it can be reused in glycolysis and ensure more ATP is continued to be produced.
