Flashcards in Chapter 15 Notes Deck (26):
Fuels (carbohydrates, fats) --> CO2 + H2O + useful energy
Useful energy + simple precursors --> complex molecules
Whether or not a reaction occurs depends on what 2 parameters?
1) two reactions can be coupled 2) the overall free energy charge for coupled reactions is equal to the sum of the free energy changes of the individual steps
If a reaction is thermodynamically unfavorable how can it be driven forward?
By coupling it with a thermodynamically favorable reaction
What do reactions using energy coupling often involve?
The hydrolysis of ATP
ATP + H2O --> ?
ADP + Pi
AMP + PPi
When can energy be released more when undergoing substrate-level phosphorylation?
When the standard energy in cellular processes has greater ATP
Why can ATP be stored until needed?
It is kinetically stable
Energy is stored in what form?
What does the energy charge tell you?
How much ATP is present (how much energy is present)
The intermediate position of ATP allows for what?
It enables ATP to function efficiently as a carrier of phosphoryl groups.
Why are ATP and other compounds activated carriers of phosphoryl groups?
Because the transfer of phosphoryl groups is exergonic
What is the chemical energy currency in the cell based on?
How does ATP hydrolysis couple to unfavorable reactions?
With the reaction of enzymes. ATP releases a phosphate group when hydrolyzed and the enzyme readjusts itself so other reactants are more favorable and energy is transferred and raised so the reaction will move forward.
The energy status of any given cell is manifested by what?
Oxidation ____ energy.
What is the difference between energy of the reactants and products?
The energy extracted during oxidation
Why will fatty acids lose the most amount of energy?
Because they have more carbons and more hydrogens attached
Are fatty acids or carbohydrates easier to break down? Why?
CHOs because they are more branched and accessible. Enzymes can go to branches more easily to break down components of energy
What does biosynthesis require?
What does energy production require?
The extraction of fuels can be divided into what three stages?
1) fats --> fatty acids and glycerol
2) polysaccharides --> glucose and other sugars
3) proteins --> amino acids
All the above to acetyl CoA
Citric acid cycle
What two compounds serve as 2 electron acceptors in oxidation and reduction reactions?
What are the enzymes that catalyze reactions using NAD+ and NADP+ as a coenzyme?
Dehydrogenases and oxidoreductases
NAD+ follows what mechanisms?
Catabolism and energy production