1. Cellular Respiration

2. So exactly how much energy does photosynthesis capture?
THE gummy bear Video

3. Cell Energy
Energy comes in many forms, including light, heat, and electricity. It is also stored in things like food and batteries.
Energy cannot be created or destroyed, but it can change forms
Cells use the energy in food to charge special cell batteries called ATP

4. Adenosine triphosphate (ATP)
ATP is the chemical compound that cells use for energy
Modified nucleic acid
made up of:
- adenine (N containing compound)
- ribose (5 C sugar)
- 3 phosphate groups

5. ATP
Reminder: cells use ATP for active transport, maintaining homeostasis, and cellular movement

6. Adenosine diphosphate (ADP)
ADP is a “dead battery” formed when a “P” is broken off the ATP to release energy. ADP can be recharged by using carbohydrate energy to reconnect the lost P.
contains:
- adenine (N containing compound)
- ribose (5 C sugar)
- 2 phosphate groups

7. ADP vs. ATP
The process of recharging ATP using carbohydrates is called Respiration
a single carbohydrate glucose (sugar) contains enough energy to recharge 90 ATP.

8. Overview of Cellular Respiration
Cellular respiration is the process that releases energy from glucose (best when in the presence of oxygen at the mitochondria) to recharge ATP.
Equation:
6O2 + C6H12O6 → 6CO2 + 6H2O + energy (ATP)
oxygen + glucose → carbon dioxide + water + energy
MEMORIZE THIS!
(Does it look familiar?!)

9. YES!
The equation for cellular respiration is the exact opposite of that of photosynthesis!
Photosynthesis:
6CO2 + 6H2O + energy → 6O2 + C6H12O6
Respiration:
6O2 + C6H12O6 → 6CO2 + 6H2O + energy
Photosynthesis and Respiration together make a cycle called the Carbon cycle.

11. Respiration
ALL cells (including plants) undergo respiration in order to recharge their ATP
Respiration reverses the work of photosynthesis. It uses oxygen to break down a sugar, releasing CO2 and water as waste
Two types of respiration
Aerobic (requires oxygen, takes place in the cytoplasm and mitochondria, creates ATP per glucose)
Anaerobic (no oxygen needed, takes place in the cytoplasm, creates only 2 ATP per glucose, also called fermentation)

12. Overview of Cellular Respiration
Three main stages (Aerobic requires all three stages, anaerobic only requires stage one)
1. glycolysis (in the cytoplasm): break glucose in half and charge 2 ATP; no oxygen needed
2. Krebs Cycle (in the mitochondria): further break down the pieces of glucose and release energy for ETC; requires oxygen
3. Electron Transport Chain (in the mitochondria): use the energy from the Krebs Cycle to charge an additional ATP; requires oxygen

13. Overview of Cellular Respiration

14. Gross vs Net ATP
Glycolysis (stage one) occurs first. It does not require oxygen, but it does require a little ATP. Glycolysis uses 2 ATP to make 4 ATP, so the NET production = 2 ATP

15. Glycolysis Notes
This process is so fast that thousands of ATPs can be produced in a few milliseconds!
Some small cells that don’t need a lot of energy can survive only through glycolysis (ex: bacteria, yeast).

16. After Glycolysis
If oxygen is present, then the products of glycolysis move on to the mitochondria for stages 2 and 3. There they will be further broken down to create MUCH more ATP energy.

17. What if oxygen is NOT present?
If there is no oxygen, anaerobic respiration (AKA fermentation) is used to keep glycolysis going (2 ATP is better than no ATP!)

18. Types of Anaerobic Fermentation
1. Alcoholic Fermentation: used by yeast; produces alcohol and CO2 to keep glycolysis going
2. Lactic Acid Fermentation: used by multicellular animals: produces lactic acid to keep glycolysis going; reason for burning muscles when working out

19. Anaerobic Respiration Reminder
The purpose of both alcoholic and lactic acid fermentation is to keep glycolysis going. Anaerobic respiration of any type only makes 2 ATP per glucose.

20. ATP Totals
Glycolysis alone (anaerobic respiration/Stage One only) produces 2 ATP molecules per glucose
With O2, Aerobic Respiration (all three stages) produces ATP molecules per glucose!
The remainder of the energy in glucose is converted to heat which helps maintain body temperature.

21. Comparing Photosynthesis & Cellular Respiration
function
energy capture
energy releases
location
chloroplasts
mitochondria
reactants
CO2 and H2O
C6H12O6 and O2
products
equation
6CO2 + 6H2O → C6H12O6 + 6O2
C6H12O6 + 6O2 → 6CO2 + 6H2O
energy
energy