Flashcards in Ch. 5: Energetics of Biological Systems Deck (17):

1

## 3 ways rate of rxn can be altered?

###
1) ⬆️ [reactants] (not practical/desirable)

2) ⬆️ temp (not practical)

3) Add catalyst (enzyme) (practical)

2

## What is the 1st law of thermodynamics?

### Energy can neither be created nor destroyed

3

## What is the 2nd law of thermodynamics?

### Entropy of the system & surroundings ⬆️ & attain max value at equilibrium

4

## Exergonic vs endergonic rxns?

###
Exergonic: spontaneous, release energy

Endergonic: thermodynamically unfavorable

5

## What is the equation for Gibbs free energy?

###
🔺G = 🔺H - T(🔺S)

6

## 🔺G* < 0 is seen in which type of rxns?

### Spontaneous (exergonic) rxns

7

## 🔺G* > 0 is seen in which type of rxns?

### Non-spontaneous (endergonic) rxn

8

## 🔺G* vs 🔺G?

###
🔺G* = standard free energy change at pH 7

🔺G = change in free energy

9

## If 🔺H is a major contributor to a rxn, what does this mean about the rxn? (Enthalpy driven rxn)

### Rxn involves ionic interactions, H bonding (heat has to be changed)

10

## If 🔺S is a major contributor to a rxn, what does this mean about the rxn? (Entropy driven rxn)

### Rxn involves hydrophobic/hydrophilic interactions

11

## As Keq ⬆️, what happens to 🔺G*?

###
🔺G* ⬇️

(Tendency for rxns to occur ⬆️ spontaneously)

12

## How many high energy bonds does ATP posses?

### 2

13

## What type of 🔺G* does ATP have?

### Large, negative free energy of hydrolysis

14

##
Rxn type: A ➡️ B

Rate eqn? Reaction order?

###
Rate = k[A]

1st order rxn (no collision needed)

15

##
Rxn type: A + B ➡️ C + D

Rate eqn? Reaction order?

###
Rate = k[A][B]

Second order rxn

16

##
Rxn type: A + A ➡️ D

Rate eqn? Reaction order?

###
Rate = k[A]^2

Second order rxn

17