1. RESPIRATION
Respiration is the process by which the chemical bond energy stored in nutrients is released for use in cells

2. RESPIRATION

3. Why do cells need energy? To make new molecules
Synthesis and hydrolysis
For building membranes and organelles
Active transport
Muscle contraction\movement
Cell division
Etc etc

4. Some facts about respiration:
Occurs continuously in all living things
Is a series of enzyme controlled reactions
May or may not use oxygen
Involves the exchange of gases between the organism and the environment
The energy in glucose is released when bonds are broken
The energy is stored in molecules of ATP

6. What is ATP???
Just kidding! Don’t use this answer on the regents!!!

7. What is ATP ?
ATP (adenosine triphosphate) is an energy storage compound that stores the energy from glucose and transfers it to other biochemical reactions

8. When energy is needed by the cell:
ATP + H2O  ADP + P + energy
The enzyme ATP-ase controls the reaction
This is a hydrolysis reaction

10. Two types of Respiration
Aerobic Respiration
Uses oxygen
Occurs in the mitochondria of cells
The more energy a cell needs the more mitochondria it will have (for example muscle cells)

11. Aerobic Respiration
Produces 36 molecules of ATP for each molecule of glucose
Reactants are oxygen and glucose
Products are water, carbon dioxide and ATP

12. General Equation
C6H12O6 + 6O2- 6H2O + 6CO ATP

13. Two Types of Respiration
Anaerobic Respiration
Does not require oxygen
Occurs in the cytoplasm
Used by yeasts and some bacteria
Net result of ATP produced is 2 molecules for each molecule of glucose
Also called fermentation

14. Anaerobic respiration
Reactant is glucose
Products are carbon dioxide
and ethyl alcohol
or lactic acid

15. General Equations Glucose-- 2 lactic acid + 2 ATP
(occurs in bacteria and muscle cells lacking oxygen)
Glucose ----- 2 alcohol + 2 carbon dioxide + 2 ATP
( occurs in yeast cells)

16. Making bread and alcohol use the process of fermentation

17. Respiration

18. Muscle Fatigue
If muscle cells don’t have enough oxygen, they will carry out anaerobic respiration
This will produce lactic acid and cause sore muscles and muscle fatigue

19. That was too easy!! C6H12O6 + 6O2- 6H2O + 6CO2 + 36 ATP
Even thought the chemical reaction for respiration makes it look simple, it is really a series of complex chemical reactions!

20. That Was Too Easy!
So Put On Your Thinking Caps!

21. If it were one simple step, all the energy would be released at once and most would be released as heat or light.
This would not provide the cell with the continuous supply of energy the it needs.

22. The Steps of Cellular Respiration:
1. GLYCOLYSIS
2. KREBS CYCLE
3. ELECTRON TRANSPORT CHAIN
Helpful information:
NAD and FAD are co-enzymes that act as Hydrogen/electron carriers

23. Glycolysis
In this first step, glucose is broken down into to smaller molecules called pyruvic acid ( a 3 carbon sugar)

24. Glycolysis
Glycolysis occurs in the cytoplasm and does not require oxygen
This step requires that 2 molecules of ATP be used for activation energy, however 4 molecules are produced, for a net total of 2 from this stage

25. C6H12O6 = glucose
2 C3H4O3 = 2 pyruvic acids
What’s missing?
Missing 4 H’s
When glucose is broken down into pyruvic acid, 4 extra H’s are picked up by NAD and transferred to other biological pathways

26. The Krebs Cycle (citric acid cycle)
Pyruvic acid is broken down into carbon dioxide (this is what we exhale) in a series of energy extracting reactions
Some ATP is produced (2)
Additional NADH and FADH2 are formed which carry high energy electrons to the electron transport chain

28. The Electron Transport Chain
The electron transport chain uses the high energy electrons from the Krebs cycle (brought by the NADH and FADH2) to convert ADP to ATP
Oxygen acts as the final hydrogen acceptor and combines with 2 hydrogens to make water which is excreted or used for cell metabolism

29. Heat O2 ATP H2O NAD+ NADH CO2 Glucose ATP Pyruvate MITOCHONDRION
Electron
Transport
System O2
ATP
H2O
NAD+
NADH
CO2
citric acid
cycle
Glucose
ATP
Pyruvate
ATP
MITOCHONDRION

30. The Totals 1 molecule of glucose produces:
Glycolysis= 2 ATP (4 – 2 for activation energy)
Kreb Cycle= 2 ATP
Electron Transport Chain = 32
For a grand total of 36 molecules of ATP

31. Is this efficient?
Respiration is more efficient than a car engine that burns gasoline!
The 36 molecules of ATP that are made from 1 molecule of glucose represent about 38% of the total energy in glucose.
What do you think happens to the other 62%
It is released as heat