Bioenergetics Flashcards
At rest how much ATP does the body make a day?
1/2 your body weight. With normal amounts of work your full body weight and with heavy work one tonne.
What does chemiosmosis involve?
One or more energy release reactions. Redox creates a transmembrane gradient used to make ATP and ATP can make an energy gradient.
What are the two main sources for the Proton Motive Force?
Respiration and photosynthesis.
What are the three main uses of PFM?
ATP synthesis.
Motility.
Soulte transport.
What is the central dogma of energy conversion?
‘Release, transfer, trapping.’
Redox… transmembrane gradient…. ATP synthesis.
What step of the central drogma of energy conversion is reversible?
Transmembrane gradient…. ATP synthesis.
What step of the central dogma of energy conversion is not easily reversible?
Redox… transmembrane gradient.
How can a cell membrane resit osmosis?
If work is put in to push in the opposite direction.
What does a ‘leaky membrane’ result in?
The movement of some H+ through the membrane without any useful energy being produced.
Why do the outer membrane in bacteria and mitochondria not use chemiosmosis?
They have holes in them.
Where is the N phase found in regards to a cell?
Outside and inside an organelle.
Where is the P phase found in regards to a cell?
In the cytoplasm.
What two things can cause the breakdown of the cytoplasmic membrane?
Lsyzome and osmotic shock.
What type of bacterium does the P and N phase apply to?
Intact bacteria.
In gram negative bacteria what phase is the periplasm considered as?
P.
In what phase is ATPsynthase normally found?
N.
After osmotic shock and lyzosome activity where is the ATPase found?
Right-side-out of vesicle (N).
After the french press where is the ATPase found?
Outside out (O).
What are Mitchells 4 postulates?
- Respiratory and photosynthetic electron transfer should translocate protons.
- The ATPase should function as a reversible proton translocating ATPase.
- Energy transducing membranes should have a low effective proton conductance.
- Energy transuding membranes should posses specific exchange carriers to permit metabolites to penetrate and osmotic stability to be maintained at a high energy potential.
Why did measuring the driving force allow?
- Quantitative approach allowing calculation away from equilibrium.
- The replacement of the wrong idea about a high energy intermediate.
- Eliminates thermodynamically imposible reactions.
Energy from ATP does not come from the high energy phosphate bond. Where does the energy come form instead?
How far the mass action ratio is equilibrium.
What drives a reaction?
A increase in entropy.
How can you asses the entropy change of a system?
Measuring the flow of heat/ enthalpy across a system.
In photosynthesis what can Gibbs energy quantify?
Light absorption.