Biochem Basics

Question 1

Thermodynamics

Answer 1

The study of energetics of chemical reactions

Question 2

Kinetic energy

Answer 2

Movement of molecules

Question 3

Potential energy

Answer 3

Energy stored in chemical bonds

Question 4

First Law of Thermodynamics (alt. name)

Answer 4

The Law of Conservation of Energy

Question 5

First Law of Thermodynamics (def.)

Answer 5

Energy of the universe is constant. This implies that when the energy go a system decreases, the energy of the surroundings/rest of the universe must increase, or vice versa

Question 6

Second Law of Thermodynamics (def.)

Answer 6

The disorder, or entropy, of the universe tends to increase; spontaneous reactions tend to increase the disorder in the universe

Question 7

Entropy Symbol/Letter

Answer 7

S

Question 8

Change in Entropy Denotation

Answer 8

Delta S

Question 9

Entropy Equation

Answer 9

Delta S = S (final) - S (initial)

Question 10

If the Delta S of a system is negative, has the disorder of that system increased or decreased?

Answer 10

If Delta S is negative, then the system has lost entropy, which means disorder has decreased

Question 11

Gibbs free energy Equation

Answer 11

Delta G = Delta H - T(Delta S)

Question 12

What does Delta H stand for?

Answer 12

Enthalpy

Question 13

Enthalpy Equation

Answer 13

Delta H = Delta E + P(Delta V)
E represents the bond energy of products or reactants in a system

Question 14

Delta G relationship to Delta H

Answer 14

Delta G increases with increasing enthalpy (Delta H)
Directly proportional

Question 15

Delta G relationship with Delta S

Answer 15

Delta G decreases with increasing entropy (Delta S)
Indirectly proportional

Question 16

What kind of Delta G do favorable reactions have?

Answer 16

Delta G < 0
This is a decrease in free energy, which makes reactions more favorable because Gibb’s Free Energy Equation tells us that increasing entropy (S) makes a reaction more favorable

Question 17

Delta G in Spontaneous reactions

Answer 17

Delta G < 0 (negative)

Question 18

Exergonic (def.)

Answer 18

Energy exits the system; spontaneous

Question 19

Delta G in Exergonic Reactions

Answer 19

Delta G < 0 (negative)

Question 20

Delta G in non spontaneous Reactions

Answer 20

Delta G > 0 (positive)

Question 21

Endergonic (def.)

Answer 21

Endergonic reactions only occur if energy is added to the system; energy input is required; nonspontaneous

Question 22

Delta G in Endergonic reactions

Answer 22

Delta G > 0 (positive)

Question 23

Exothermic (def.)

Answer 23

Heat is liberated/ released from the system

Question 24

Most metabolic reactions in the body are exothermic or endothermic?

Answer 24

Exothermic

Question 25

Delta H in Exothermic reactions

Answer 25

Delta H < 0 (negative)

Question 26

Endothermic (def.)

Answer 26

Heat is added/ input to the system

Question 27

Delta H in Endothermic reactions

Answer 27

Delta H > 0 (positive)

Question 28

What free energy state does the system go into with a negative Delta G? (Higher or Lower)

Answer 28

Lower - Think of a spinning top slowing down and moving towards a lower energy state; negative delta G means energy is leaving the system, and therefore there is lower free energy