Text Readings in Lewis	Review questions	"To think about"
Chapter 3 Proteins & Enzymes Pages 48-53 Chapter 6 Energy, ATP, NADPH Pages 113-122 Chapter 7 How Cells Release Energy Pages 125-143	Page 143-4 Questions 1,2,5,10,13 &15	Page 144 questions 1,2 & 4

The "Mastering Concept" boxes are valuable summaries of the main ideas in these sections of the text.

Objectives:

After studying this material you should be able to:

1. Describe the energy transformations that occur in the cytoplasm and mitchondria as chemical energy from glucose and other compounds is converted to the chemical bond energy of ATP.

2. Draw a sketch of a mitochondrion and the adjacent cytoplasm and indicate where these energy transformations take place.

3. List the inputs (raw materials) and outputs (products) of glycolysis, the Krebs Cycle, and the respiratory (electron transport) chain.

4. Describe the roles of ADP, ATP, NAD+, NADH, and a proton gradient in the enzyme reactions of the Krebs Cycle and the respiratory (electron transport) chain.

5. Explain where in the respiratory pathway CO2 is produced.
6. Describe the role of oxygen in the process of aerobic Respiration.
7. Explain how weight loss and CO2 production are inseparably linked.
8. Explain how proteins and fats may be utilized by the enzymes involved in respiration.
9. Explain the role of the respiratory pathways in the processing of compounds for biosynthesis.
10. Compare the energy output of the anaerobic pathways (alcoholic and lactic acid fermentation) to that of aerobic respiration.

Respiration Links

The Virtual Cell developed by Mat Lexa right here at the U of I.

Glycolysis and the Krebs Cycle from the MIT Biology Hypertext book. (referenced below)

O2 +

Carbohydrate & Other Organic Compounds*

+ ---

Living Cells

--->

ATP & Heat*

+ CO2 + Water

Overview of Respiration (See Lewis fig. 7.5)

Organic Compounds* From Food	--->	Glycolysis (Enzyme Reactions in Cytoplasm)	--->	Pyruvic Acid* some ATP*	--------->
Krebs Cycle (Enzyme Reactions in Mitochondria)	--->	NADH* & CO2	--->	Proton Gradient*	--->	Lots of ATP*

Glycolysis (in the cytoplasm) (see Lewis, figures 7.9)

• Glucose* Activation (use of ATP*)

• Enzyme Reactions

• Energy Extraction (Production of ATP* & NADH*)

• Production of Pyruvic Acid*

• Outer membrane

• Inner membrane systems
  • Cristae

  • Electron Carriers of repiratory chain

  • ATP Synthase

• Matrix (liquid area within the inner membrane)
  • Enzymes of Krebs Cycle)

  • DNA

  • Ribosomes

• Intermembrane space (liquid area between the inner and outer membranes)
  • Concentration of Protons)

The Krebs Cycle (see Lewis, figure 7.11)

• Pyruvic Acid* converted to Acetyl CoA* + CO2

• Enzyme Reactions

• Acetyl CoA* combined with 4C compound to make Citric Acid*

• Citric Acid* broken down step-by-step

• CO2 released

• NAD+ reduced (e- added) to NADH*

• 4C compound regenerated

• NADH* provides e- to respiratory chain producing NAD+

• O2 accepts the e-, combines with H+, and produces H2O

• e- flow through respiratory chain pumps protons to intermembrane space producing a Proton Gradient*

• Proton movement* through ATP synthase

• ADP + Phosphate ions ----> ATP

Anaerobic Fermentation (see Lewis, figure 7.17 & 7.19)

• Occurs when O2 is not available in plants & yeasts

• Alcoholic Fermentation
  • Pyruvic Acid* converted to Ethyl Alcohol* and CO2

  • A small amount of ATP* is produced)

• Lactic Acid Fermentation
  • Occurs when O2 is not available in animals & some bacteria

  • Pyruvic Acid* converted to Lactic Acid*

  • A small amount of ATP* is produced)