1. Energy in Living Organisms
How is energy created in the cells/body?

2. Metabolism
all the chemical reactions that occur within a cell to keep it living.
includes the building up and the breaking down of substances.
a cell’s metabolism relies on chemical energy created by cellular respiration

3. Cellular Respiration
a series of chemical reactions needed to break down carbohydrates and other molecules in order to release the energy they contain.
when chemical bonds are broken energy is released.
when bonds are broken the energy released and is temporarily stored in a compound called adenosine triphosphate (ATP).

4. Cellular Respiration ATP is the currency cells
use for processes like muscle
contraction, sending nerve impulses or pumping substances across the cell membrane.
ATP is made up of 3 phosphate molecules. When one phosphate is removed, the energy is released and a new substance adenosine diphosphate (ADP) is made.

5. ATP  ADP + Phosphate +
Energy

6. How is ATP made?
Energy has to be converted to usable forms to have the desired effect.

7. How is ATP made? There are two types of cellular respiration.
Aerobic Respiration
Anaerobic Respiration

8. Aerobic Respiration Energy
uses oxygen and produces large amounts of ATP.
consists of two stages:
A. Glycolysis
happens in the cytoplasm
converts glucose into a molecule called pyruvate
makes only 2 ATP
C6H12O6  2 C3H6O ATP
(glucose) (pyruvate)
Energy

9. Aerobic Respiration Lots of Energy
B. Kreb’s Cycle (Oxidative respiration)
if oxygen is available
pyruvate is transported into the mitochondria
converts pyruvate into water and carbon dioxide
makes 34 ATP
2 C3H6O3  6CO H2O ATP
(pyruvate)
Lots of Energy

10. Aerobic Respiration Summary C6H12O6 + O2  CO2 + H20 + 36 ATP Water
Carbon Dioxoide
Water
Energy
Sugar
Oxygen

12. What now?
Text page 72 #19-21
Write out a word equation or chemical equation showing aerobic cellular respiration?
What are the 2 different stages of aerobic respiration? Where do they occur?

13. 2. Anaerobic Respiration
does not use oxygen and produces small amounts of ATP.
this method is referred to as fermentation.
there are two types:
Alcoholic (Ethanol) Fermentation
Lactic Acid Fermentation

14. Anaerobic Respiration
1. Alcoholic Fermentation
Glycolysis breaks down glucose to produce pyruvate + 2 ATP
Pyruvate is converted to ethanol and carbon dioxide *This process is only used by plants, some bacteria, yeast
Uses?
baking, alcoholic beverages

15. Alcoholic Fermentation

16. Anaerobic Respiration
Lactic Acid Fermentation
Glycolysis breaks down glucose to produce Pyruvate + 2 ATP
Pyruvate breaks down to form lactic acid
Advantages?
While only producing small amounts of ATP the process is very fast! (Doesn’t last long though)

17. Cellular Respiraton Summary
Glucose
2 ATP (through Glycolysis)
2 Pyruvate
Oxygen
No Oxygen
Aerobic Respiration
34 more ATP!
Fermentation (Anaerobic Respiration)
Alcohol + CO2
(yeast, plants)
Lactic acid
(animals)

19. What now?
Text page 77 #22-24
Page 77 Mini Activity 2-5 – Lactic Acid Friend or Foe
Research online to find out how scientists used to explain muscle fatigue as a by-product of lactic acid fermentation. Describe your findings.
What is the most current explanation for muscle fatigue?