Inputs Outputs Location in the Cell

Glycolysis Glucose, ADP + PNAD+ + H+ ATP

2 Pyruvate , ATPNADHADP + P

Cytoplasm

Link Reaction 2 PyruvateNAD+ + H+

2 Acetyl – CoA, 2 CO2

NADH

Matrix of Mitochondria

Krebs Cycle 2 Acetyl – CoANAD+ + H+ FAD +2 H+

4 CO2

NADHFADH2

Matrix of Mitochondria

Oxidative Phosphorylation (ETC)

O2 + 2 H+ NADHFADH2

ADP + P

H2ONAD+ + H+ FAD +2 H+ *****ATP *****

Inner mitochondrial membrane and matrix of mitochondria

Light Dependent Reaction

H2ONADP+ + H+ ADP + P

O2 + 2 H+ NADPHATP

Inner thylakoid membrane and stroma of chloroplast

Calvin Cycle (Carbon Reactions, Light Independent Rxn)

CO2 NADPHATP

PGAL GlucoseNADP+ + H+ ADP + P

Stroma of chloroplast

Glycolysis (cytoplasm)

Pyruvate processing (membrane b/w

cytoplasm and mitochondria)/ Citric acid Cycle (mitochondrial matrix)

Electron Transport Chain (mitochondrial membrane)

Cellular Respiration Animationhttps://www.youtube.com/watch?v=-Gb

2EzF_XqA

Why do you suffocate when you lose access to oxygen?

a. Explain what happens inside your mitochondria when you lose access to oxygen and why this poses such a dire problem for your cells.

b. How is it that some other organisms don’t suffocate in oxygen-free environments, and in fact thrive there?

Explain what the point of the “energy investment” phase of Glycolysis is. Why put in ATP, if the cell wants to get ATP out of it?

Metabolism

The totality of an organism’s chemical processes.

Concerned with managing the material and energy resources of the cell.

Catabolic Pathways

Pathways that break down complex molecules into smaller ones, releasing energy.

Example: Respiration

Anabolic Pathways

Pathways that consume energy, building complex molecules from smaller ones.

Example: Photosynthesis

Energy Ability to do work.

The ability to rearrange a collection of matter.

Forms of energy:KineticPotentialActivation

Energy Transformation

Governed by the Laws of Thermodynamics.

1st Law of Thermodynamics

Energy can be transferred and transformed, but it cannot be created or destroyed.

Also known as the law of “Conservation of Energy”

2nd Law of Thermodynamics

Each energy transfer or transformation increases the entropy of the universe.

Entropy Measure of disorder

A

B

Summary

The quantity of energy in the universe is constant, but its quality is not.

Question?

How does Life go against Entropy?

By using energy from the environment or external sources (e.g. food, light).

Free Energy

The portion of a system's energy that can perform work.

DG = DH -

T* DS

Any reaction that decreases DG is thermodynamically favorable and occurs spontaneously.DGreaction = Gproducts -

Greactants

If DG is negative, free energy is released and the reaction proceeds spontaneously. EXERGONICIf DG is positive, addition of energy (work) is required for the reaction to proceed. ENDERGONICIf DG is zero, the system is in equilibrium.

Change in Gibbs free

energy

change in potential energyof the

system

change in the

disorderof the

system

We can use Gibbs free energy to predict when reactions are spontaneous :

Fig. 4.9

Coupled endergonic and exergonic reactions

Exergonic reaction Endergonic reaction

before

after

Gib

bs

free e

nerg

y overall DG

Almost every endergonic process performed by organisms is powered by the hydrolysis of ATP, including

C6H12O6 + 6 O2 6 CO2 + 6 H2O

Aerobic Cellular Respiration

36 ADP + 36 Pi 36 ATP

DG = –2870 kJ/mol

DG = +992 kJ/mol

DGtotal = -1878 kJ/mol

Inputs:

Outputs:

The Big Picture

Fig. 5.3

Fig. 5.4

All of the oxygen in Earth’s atmosphere was produced (and is continually replenished) by photosynthesis. Explain why plants produce an excess of oxygen.

a. Where is the oxygen that is released by photosynthesis coming from?

b. What do plants do with the sugar that is produced by photosynthesis?

c. Given that plants have mitochondria as well that engage in cellular respiration, can you explain how there is still an excess of oxygen that gets released by the plants?

Photosynthesis Animations

Light Dependent Reactionshttp://www.science.smith.edu/departments/Biology/Bio

231/ltrxn.html

Calvin Cyclehttp://www.science.smith.edu/departments/Biology/Bio

231/calvin.html

Cellular Respiration Animations

Glycolysishttp://www.science.smith.edu/departments/Biology/Bio231/

glycolysis.html

Krebs Cyclehttp://www.science.smith.edu/departments/Biology/Bio231/kr

ebs.html

Electron Transport Chainhttp://www.science.smith.edu/departments/Biology/Bio231/et

c.html