Principles Of Metabolism

Question 0

Evolution of mitochondria

Answer 0

Mitochondria were originally free-living bacteria –> incorporated –> symbiotic relationship
Bacteria also use PMF to drive uptake of nutrients across cell wall
Some antibiotics are protein ionophores that kill bacteria by collapsing PMF eg topical antifungal - nystatin

Question 1

PMF provides the energy for ATP synthesis

Answer 1

Agents that collapse this PMF inhibit ATP formation

These compounds are weak lipophilic acids that carry protons across IMM eg 2,4-dinitrophenol and salicylic acid

Question 2

Worlds smallest motor

Answer 2

F1 can be disassociated from F0 by protease
When not linked to F1, F0 acts as ATPase
ATP hydrolysis drives the rotation of F1 subunit
Fix a3B2 hexameter to a glass surface with y projecting upward and linked to fluorescent actin filament - see it rotate 120 counterclockwise with microscope

Question 3

Krebs cycle one to one relationship with intermediate

Answer 3

Block succinctness dehydrogenase –> turns Krebs cycle into open pathway
Each Acetyl CoA oxidised, one molecule of oxaloacetate required

Question 4

Enzyme complexes harness some energy to pump protons

Answer 4

Purify and incorporate enzymes into lysosomes
When appropriate electron donor and acceptors are added electrons can pass through the complex –> protons are translocated across the membrane (volt meter)

Question 5

Krebs cycle is a cycle

Answer 5

Minced pigeon breast meat and suspended in saline solution
In absence of oxygen, large amounts of citrate formed by minced meat if both oxaloacetate and pyruvate were added, but not if either component were omitted
In presence of mason ate –> known inhibitor of succinctness oxidation –> succinctness accumulated when citrate and oxaloacetate added
Succinctness is more reduced than oxaloacetate –> formation with uptake of oxygen must imply occurrence of a cyclic, oxidative sequence of reactions