1. Unit 3 – Chapters 9 + 10 Bioenergetics
How do living organisms (both animals and plants) generate and utilize energy?

2. Chemotrophic Bacteria (NOT on test, just interesting exception to normal cellular respiration and photosynthesis)
In 1970’s bacteria discovered near hot, volcanic vents on the ocean floor that extract energy from sulfides to reduce CO2 without using sunlight.

3. Organic molecules Cellular respiration in mitochondria
Fig. 9-2
Light
energy
ECOSYSTEM
Photosynthesis
in chloroplasts
Organic
molecules
CO2 + H2O
+ O2
Cellular respiration
in mitochondria
ATP
ATP powers most cellular work
Heat
energy

4. Overall Reactions CELLULAR RESPIRATION PHOTOSYNTHESIS
Chapter 9 – Cellular Respiration – occurs in both plants and animals; how is energy obtained from the metabolism of carbohydrates (and in less detail also proteins and fats)?
CELLULAR RESPIRATION
becomes oxidized
becomes reduced
PHOTOSYNTHESIS
ENERGY + 6 CO2 + 6 H2O → C6H12O6 + 6 O2
Chapter 10- Photosynthesis – how do plants build energy rich sugar molecules using CO2, H2O and sunlight?

5. Goals of Cellular Respiration and Photosynthesis:
1) Make Energy storage molecule ATP that can used for cellular work
2)Provide building blocks for important molecules the cell needs

6. Figure 9.5 An introduction to electron transport chains
Link to hydrogen + oxgyen video

8. Direct Transfer electrons vs. Indirect transfer of electrons

9. Direct Transfer of electrons between Zn and Cu+2 ions

10. Indirect transfer of electrons through a wire; Flowing e- can be used to do work.
Link to video clip

11. Link to M and M combustion
Link to gummy bear

12. Source of electrons for electron transport chain
Cellular Respiration → e- obtained from gradual, controlled oxidation of energy-rich molecules such as glucose
Photosynthesis → e- obtained by oxidizing water using visible light

13. NADH and FADH2 serve as electron carriers
2 e– + 2 H+
2 e– + H+
NADH H+
Dehydrogenase
Reduction of NAD+
NAD+ +
2[H] + H+
Oxidation of NADH
Nicotinamide
(reduced form)
Nicotinamide
(oxidized form)
LOW ENERGY OXIDIZED FORM
HIGH ENERGY REDUCED FORM
NAD+
FAD
NADH
FADH2
Link to NADH animation

14. becomes oxidized (loses electron) becomes reduced (gains electron)
Many Important Reactions in Bioenergetics Involve Oxidation –Reduction (Redox or Electron Transfer) Reactions
becomes oxidized
(loses electron)
becomes reduced
(gains electron)
“OIL RIG” = Oxidation Is Loss of electrons,
Reduction Is Gain of electrons
Link to video Na + Cl2

15. Reactants Products becomes oxidized becomes reduced Methane (reducing
Redox reactions release energy when electrons in covalent bonds move closer to more electronegative atoms
Reactants
Products
becomes oxidized
becomes reduced
Methane
(reducing
agent)
Oxygen
(oxidizing
agent)
Carbon dioxide
Water
Link to video CH4 + O2

16. Fig. 9-UN4
Dehydrogenase

17. Cell’s ATP Requirements
Each Human cell contains approximately 1 billion ATP/ ADP molecules. Each ADP is recycled to ATP approximately 3 times per minute.
By recycling ADP to ATP, body requires approximately 50 grams of ATP. Without recycling you would require about 400 lbs of ATP in your diet in day!

18. SYNTHESIS OF ATP USING SUBSTRATE LEVEL PHOSPHORYLATION
Enzyme
Enzyme
ADP P
Substrate +
ATP
Product
FORMATION OF ATP VIA ENZYME CATALYZED TRANSFER OF PHOSPHATE TO ADP
OCCURS IN GLYCOLYSIS AND KREBS CYCLE
LESS EFFICIENT METHOD OF SYNTHESIZING ATP THAN OXIDATIVE PHOSPHORYLATION

19. Synthesis of ATP by Oxidative Phosphorylation
Most efficient method of synthesizing ATP; used in both cellular respiration and photosynthesis

20. MAKING ATP BY OXIDATIVE PHOSPHORYLATION
Protein complex
of electron
carriers
Cyt c V Q
 
ATP synthase 
2 H+ + 1/2O2
H2O
FADH2
FAD
NADH
NAD+
ADP + P
ATP i
(carrying electrons
from food) H+ 1
Electron transport chain 2
Chemiosmosis
Oxidative phosphorylation
USED IN BOTH CELLULAR RESIRATION AND PHOTOSYNTHESIS