Lecture 2 outline ch 8 9
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Lecture 2 Outline (Ch. 8, 9). Energy Thermodynamics Metabolism and Chemical Reactions V.Cellular Energy - ATP Enzymes & Regulation Cell Respiration Redox Reactions Glycolysis Coenzyme Junction VII. Preparation for next Lecture. Energy. What is Energy?.

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Lecture 2 Outline (Ch. 8, 9)

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Lecture 2 outline ch 8 9

Lecture 2 Outline (Ch. 8, 9)

  • Energy

  • Thermodynamics

  • Metabolism and Chemical Reactions

  • V.Cellular Energy - ATP

  • Enzymes & Regulation

  • Cell Respiration

    • Redox Reactions

    • Glycolysis

    • Coenzyme Junction

  • VII. Preparation for next Lecture


Lecture 2 outline ch 8 9

Energy

What is Energy?

Where does energy on earth come from originally?

[equivalent of 40 million billion calories per second!]

Types of Energy:

- Kinetic Energy = energy of movement

- Potential = stored energy


Lecture 2 outline ch 8 9

Energy

Potential Energy

Kinetic Energy

Thermodynamics – study of energy transformation in a system

Potential energy can be converted to kinetic energy (& vice versa)


Lecture 2 outline ch 8 9

Thermodynamics

Laws of Thermodynamics: Explain the characteristics of energy

  • 1st Law:

    • Energy is conserved

      • Energy is not created or destroyed

      • Energy can be converted (Chemical  Heat)

2nd Law:

  • During conversions, amount of useful energy decreases

  • No process is 100% efficient

  • Entropy (measure of disorder) is increased

Energy is converted from moreordered to less ordered forms


Lecture 2 outline ch 8 9

Potential vs. Kinetic Energy


Lecture 2 outline ch 8 9

Metabolism and Energy

Cells convert molecules chemically using cellular energy.


Lecture 2 outline ch 8 9

Metabolism

Metabolism – chemical conversions in an organism

Metabolic reactions: All chemical reactions in organism

  • Anabolic = builds up molecules

Catabolic = breaks down molecules

Two Types of Metabolic Reactions


Lecture 2 outline ch 8 9

Chemical Reactions

+

+

Reactants

Products

  • Chemical Reaction:

    • Process that makes and breaks chemical bonds

  • Two Types of Chemical Reactions:

    • 1) Exergonic = releases energy

    • 2) Endergonic = requires energy


Lecture 2 outline ch 8 9

Metabolism

  • Metabolic reactions:

    • Chemical reactions in organism

Two Types of Metabolic Reactions:

  • Anabolic = build up

Catabolic = break down

Exergonic = release energy

Endergonic = requires energy


Lecture 2 outline ch 8 9

Chemical Reactions

Glucose  CO2 + H20

CO2 + H20 Glucose

-ΔG

+ΔG (or 0)

release energy

intake energy

spontaneous

non-spontaneous

• Exergonic reaction

• Endergonic reaction


Lecture 2 outline ch 8 9

Question/Recall: Which has more order? Stores more energy? Polymer or Monomer, Diffused or Concentrated H+? What is relationship between order and energy?


Lecture 2 outline ch 8 9

What type of energy is stored in a covalent bond?

A.Kinetic energy

B.Diffused energy

C.Heat energy

D.Potential energy

E. Conventional energy


Lecture 2 outline ch 8 9

Cellular Energy - ATP

• ATP = adenosine triphosphate

• ribose, adenine, 3 phosphates

• last (terminal) phosphate - removable

Be able to diagram ATP! 


Lecture 2 outline ch 8 9

ATP + H2OADP + Pi

Cellular Energy - ATP

• ATP hydrolyzed to ADP

• Exergonic

• Energy released, used in another reactions (endergonic)


Lecture 2 outline ch 8 9

Cellular Energy - ATP

• ATP regenerated

• cells power ATP generation by coupling to exergonic reactions

Like cellular respiration!


Lecture 2 outline ch 8 9

ATP Cycle


Lecture 2 outline ch 8 9

Making ATP from ADP + Pi is…

  • Exergonic because it releases energy

  • Endergonic because it requires energy

  • Exergonic because it requires energy

  • Endergonic because it releases energy


Lecture 2 outline ch 8 9

Chemical Reactions

  • Chemical Reactions:

    • Like home offices – tend toward disorder

  • Endergonic – energy taken in; Exergonic – energy given off

Exergonic

Endergonic


Lecture 2 outline ch 8 9

Self-Check


Lecture 2 outline ch 8 9

Chemical Reactions

Nucleus

Nucleus

Repel

Activation

Energy

Activation

Energy

Nucleus

Nucleus

Repel

Activation Energy: Energy required to “jumpstart” a chemical

reaction

  • Must overcome repulsion of molecules due to negative

  • charged electrons


Lecture 2 outline ch 8 9

Chemical Reactions

  • Exergonic Reaction:

    • Reactants have more energy than products

Activation energy:

Make sugar and O2 molecules collide

sugar + O2

water + CO2

“Downhill” reaction


Lecture 2 outline ch 8 9

Respiration (ch. 9) preview

Cellular Respiration Equation:

C6H12O6 + O2 CO2 + H2O

You will need to KNOW this equation.


Lecture 2 outline ch 8 9

Chemical Reactions and Enzymes

Enzymes

• lower activation energy only for specific reactions

• cell chooses which reactions proceed!

enzymes:

cannot make rxns go that wouldn’t otherwise

Cannot change endergonic into exergonic rxns

Dospeed up rxns that would occur anyway


Lecture 2 outline ch 8 9

Enzymes

• Enzymes – control rate of chemical reaction

• sucrase – enzyme sucrose breakdown

“-ase” enzyme

• sucrase – catalyst

-speed up rxn, but not consumed


Lecture 2 outline ch 8 9

Enzymes

• enzyme – specific to substrate

• active site – part of enzyme -substrate

• binding tightens fit – induced fit

• form enzyme-substrate complex

• catalytic part of enzyme: converts reactant(s) to product(s)


Lecture 2 outline ch 8 9

Enzymes

• Enzymes lowers EA by:

-template orientation

-stress bonds

• substrate(s) enter

-microenvironment

• enzyme reused

• product(s) formed

• What factors might affect enzyme activity?


Lecture 2 outline ch 8 9

Enzymes

• inhibitors:

binds & blocks active site

binds allosteric site – alters conformation

• Drug – blocks HIV enzyme at the active site


Lecture 2 outline ch 8 9

If a competitive inhibitor is in an enzyme reaction, can you reverse the inhibition by adding more substrate?

  • Yes

  • No

  • I’m not sure

  • Wait, what’s a competitive inhibitor?


Lecture 2 outline ch 8 9

Cellular Respiration

Overall purpose:

• convert food to energy

• animals AND plants

• complementary to photosynthesis


Lecture 2 outline ch 8 9

Cellular Respiration:

(Exergonic)

Cellular Respiration

• catabolizes sugars to CO2

• requires O2

• at mitochondrion


Lecture 2 outline ch 8 9

Redox Reactions

• as part of chemical reaction, e- are transferred

• e- transfer = basis of REDOX reactions

(reduction) (oxidation)


Lecture 2 outline ch 8 9

Redox Reactions

Use “H rule” for reactions in this class

Reactant with more H’s = e donor, will be oxidized

Reactant with more O’s = e acceptor, will be reduced

ZH2 + O2 yields ZO + H2O

• follow the H, e- move with them


Lecture 2 outline ch 8 9

Self-Check

Oxygen

ZH2


Lecture 2 outline ch 8 9

Redox Reactions

Equation for respiration


Lecture 2 outline ch 8 9

Redox Reactions

• transfer of e- to oxygen is stepwise


Lecture 2 outline ch 8 9

• glucose NADH ETC O2 (makes H2O)

Redox Reactions

• e- moved by NAD/H (from niacin/vit B3)

• NADH  carry e- (reduced!)

• NAD+  not carrying e- (oxidized!)

Where do e- come from?

Where do e- go?


Lecture 2 outline ch 8 9

In this equation is NAD+ to NADH oxidized or reduced?

NAD+ + H+ + 2e-  NADH

  • Reduced, it gained electrons

  • Oxidized, it gained electrons

  • Reduced, it lost electrons

  • Oxidized, it lost electrons


Lecture 2 outline ch 8 9

Steps of Respiration

• Steps of respiration:

1. glycolysis

2 CO2

Coenzyme Junction

2. Citric acid cycle

4 CO2

3. ETC

4. Chemiosmosis


Lecture 2 outline ch 8 9

Cellular Respiration

• Stages of respiration:

1. Glycolysis – prep carbons


Lecture 2 outline ch 8 9

Cellular Respiration

1. Glycolysis

• 1 glucose (6C)2 pyruvate (3C)

• Keep track of:

- inputs

- ATP

- NAD+/NADH

- CO2 and H2O

- outputs

• eukaryotes AND prokaryotes


Lecture 2 outline ch 8 9

Glucose

Glucose-6-phosphate

ATP

2

1

ADP

Fructose-6-phosphate

Glucose-6-phosphate

Glycolysis


Lecture 2 outline ch 8 9

ATP

Fructose-

1, 6-bisphosphate

ADP

4

5

Glyceraldehyde-

3-phosphate

Dihydroxyacetone

phosphate

Glycolysis


Lecture 2 outline ch 8 9

2 ADP

2 ATP

Phosphoenolpyruvate

2

2 ADP

10

2 ATP

Pyruvate

2

Glycolysis

Step not shown


Lecture 2 outline ch 8 9

How many NET ATP are produced by glycolysis?

  • one

  • two

  • four

  • six

  • eight


Lecture 2 outline ch 8 9

Cellular Respiration

Glycolysis

-inputs:

1 Glucose

2 ATP

-outputs:

2 pyruvate

4 ATP (2 net)

2 NADH

CO2 = none yet

(2 H2O)

Where do the outputs go?


Lecture 2 outline ch 8 9

Energy production

Mitochondria

• energy from nutrients  ATP


Lecture 2 outline ch 8 9

Cellular Respiration

Coenzyme Junction

• 2 pyruvate (3C) 2 Acetyl CoA (2C)

• pyruvate joins coenzyme A (from vitamin B5)

• 2 carbons lost (as CO2)

• 2 NAD+  NADH


Lecture 2 outline ch 8 9

Things To Do After Lecture 2…

  • Reading and Preparation:

  • Re-read today’s lecture, highlight all vocabulary you do not understand, and look up terms.

  • Ch. 8 Self-Quiz: #1-6 (correct answers in back of book)

  • Read chapter 9, focus on material covered in lecture (terms, concepts, and figures!)

  • Skim next lecture.

  • “HOMEWORK” (NOT COLLECTED – but things to think about for studying):

  • Describe the relationship between exergonic/endergonic, catabolic/anabolic, and “uphill”/”downhill” chemical reactions

  • Diagram one molecule of ATP and how ADP is different

  • Cut apart the boxes on the previous sheet – match up three (name, energy balance, basic reaction) for glycolysis and three for the coenzyme junction

  • Place the following molecules in order for when they are used/created during glycolysis: fructose-6-phosphate, glucose, glucose-6-phosphate, pyruvate, glyceraldehyde-3-phosphate


Self check at home match each step name with energy balance and basic reaction

Self-check at homeMatch each Step Name with Energy Balance and Basic Reaction


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