Aerobic Respiration Flashcards
Describe glycolysis.
Happens in the cytoplasm. A 6c glucose molecule is phosphorylated using 2 molecules of ATP. this becomes glucose diphosphate, because glucose is relatively unreactive compared to it so less activation energy is required, and is less polar so less likely to diffuse out. Glucose diphosphate splits into triose phosphate, which is then dehydrogenated making 2 molecules of NADH and turned into Pyruvate. This releases enough energy to attach a p group to ADP using substrate level phosphorylation, making 2 ATP.
Describe the link cycle.
Pyruvate actively transports into the mitochondrial matrix. Pyruvate + NAD + CoA - AcCoA + NADH + CO2. Pyruvate is dehydrogenated making NADH and decarboxylated making CO2. Coenzyme A combines to make AcCOA. This happens twice per glucose molecule.
Describe the Krebs cycle.
Acetyl coenzyme A from the link reaction enters the Krebs cycle as a 2c molecule and combines w a 4c molecule to make a 6c molecule, and coenzyme A is regenerated. It is then decarboxylated and dehydrogenated, making CO2 and NADH, and a 5c molecule. The 5c molecule is dehydrogenated 3 times, making 2 NADH and 1 FADH. It is decarboxylated once making CO2, and one molecule of ATP is made. It is now a 4c molecule and the cycle restarts. Dehydrogenase and decarboxylase are required for this.
Describe the electron transport chain.
Occurs on the Cristae of the mitochondria.
H from NADH and FADH split into electrons and protons. 1 NADH makes 3 ATP, 1 FADH makes 2 ATP. Electrons enter the chain on cytochromes (proteins conjugated to iron or copper) and move down the chain in w series of redox reactions releasing energy. This energy pumps protons into the intermembrane space. The membrane is impermeable to protons except through a channel associated w ATP synthase. Protons move down this channel through chemiosmosis, which releases enough energy to add a P group to ADP to make ATP. Remaining ps and es are accepted by oxygen, the final electron acceptor.
How does cyanide damage the ETC?
A non- competitive inhibitor of the final carrier in the ETC. with it, electrons and protons can’t be transferred to water so they accumulate, destroying the proton gradient so ATP synthase can’t operate and the cell dies quickly.
