'Entropy' and 'Free Energy' in Metabolism Flashcards
1
Q
What is the relation between cellular respiration and photosynthesis reactions?
A
- They are coexistent and are ultimately dependent on each other
2
Q
What are most metabolic reactions?
A
- Exothermic and exergonic
- They rely on enzyme action
3
Q
What are less common metabolic reactions?
A
- Endothermic and endergonic
- They require energy to be driven forward
4
Q
Free Energy Exchanges
A
- Cells constantly carry out thousands of exergonic and endergonic reactions
- Sometimes the free energy produced by an exergonic reaction can help drive an endergonic reaction forward
5
Q
Energy Coupling
A
Process when exergonic reactions are used to drive endergonic reactions
6
Q
Coupled Reactions
A
- Reactions where an energetically favourable (spontaneous) reaction is able to drive an energetically unfavourable reaction forward
- Reactions involved in energy coupling
7
Q
Coupled Reaction Formulas
A
- A –> B + C
- D + E –> F
8
Q
In biological reactions what molecule helps in the process of coupling?
A
ATP!!
9
Q
What is ATP?
A
- Stands for: Adenosine triphosphate
- Primary source of energy for endothermic reactions to occur in cells
10
Q
What is ATP made up of?
A
- Adenine
- Ribose sugar
- 3 phosphates
11
Q
What is inorganic phosphate?
A
- Phosphate group that has no attached carbons
12
Q
Formula of the hydrolysis of ATP
A
ATP + H2O –> ADP + Inorganic Phosphate
13
Q
In order for cells to function…
A
- They must regenerate ATP molecules
- This is done by coupling ATP and ADP molecules
14
Q
What does Pi represent?
A
Inorganic phosphate
15
Q
ATPase
A
- An enzyme that hydrolyzes the last phosphate and removes it from ATP when the cells require Gibbs free energy to work
