To energize or not to energize?

• What is energy anyway?

I. Energy

• A. definitions– 1. energy– 2. work– 3. thermal

energy

4. Types of energy

a. Kinetic energy

b. Potential energy

Potential vs. Kinetic Energy

5. Open vs. closed systems

6. Entropy

7. Types of chemical reactions

• a. endergonicstores energy

decreases entropy

not spontaneous

requires energy input

Biological example

7. Types of chemical reactions

b. Exergonic reactions

you know what to put here from the previous slide

8. Metabolism

What type of reaction is illustrated in the diagram below?

1. Anabolic

2. Exergonic

3. Catabolic

4. One that increases entropy

Fre

e en

erg

y (G

)

B. Laws of thermodynamics

• 1. First Law– Definition– Repurcussions

Plants, being autotrophs, create their own energy.

1. True

2. False

2. Second law of thermodynamics

• Energy conversions are not 100% effective

• When energy changes form, some energy is lost as waste heat

• Entropy is always increasing

Life creates order. The second law of thermodynamics says that disorder is always increasing. Do living systems violate the second law of thermodynamics?

1. Yes

2. No

3. I don’t know

Explanation of question

C. Importance of ATP

• Energy currency of cell• Produced in the

mitochondria and chloroplasts

• Used whenever the cell needs to perform work

Molecular Structure of ATP

II. Nature of chemical reactions-chaotic

A. Chaotidc

II. Nature of chemical reactions

• B. Sometimes a productive collision occurs– Powerful– Correctly oriented– Enough speed to

overcome electron repulsion

II. Nature of chemical reaction

• C. Transition state forms– Represents high energy state– Very unstable– Very short lived– Old bonds are broken – New bonds form

What type of reaction occurred in this reaction?

1. Catabolic

2. Dehydration

3. Hydrolysis

4. Ionic bond formation

5. Both 1 & 2

II. Nature of chemical reactions C. Types of chemical reactions

• Exergonic reaction Endergonic reaction• Energy coupling

III. Energetics of chemical reactions• A. Energy profile at room

temperature

III. Energetics of chemical reactions

• B. Tricks chemists play• add heat• stir• increase concentration of reactants• increase pressure on reactants• add a catalyst

Effect of heating a chemical reaction

Effect of increasing the reactants’ concentrations

IV. How Enzymes Work

A. Normally

B. Characteristics of enzyme function

C. Effect on energy dynamics

D. Molecules at biological temperatures

E. Analogy of Volkswagon on the hill