1. Cells Unit
Learning Goal #4: Describe the flow of energy and matter in cellular function.

2. All Living Things Require Energy to Function.

3. Adenosine Triphosphate “ATP”
One ATP Molecule
This molecule acts as the short-term energy currency of the cell and provides the source of energy used in reactions.
ATP collects small packets of energy from the food-burning power plants of the cell and transports this energy to where it is needed.
Some energy in ATP is released to do work, such as move muscles or force a seedling out of the ground.

4. Photosynthesis

6. Photosynthesis Overview
Process by which plants and other autotrophs store the energy of sunlight as sugars.
Requires sunlight, water, and carbon dioxide.
Overall equation:
6 CO H20  C6H12O O2
Occurs in the leaves of plants in organelles called chloroplasts.

8. Photosynthesis: The Chemical Process Occurs in two main phases.
Light reactions
Dark reactions (aka – the Calvin Cycle)
Light reactions are the “photo” part of photosynthesis. Light is absorbed by pigments.
Dark reactions are the “synthesis” part of photosynthesis. Trapped energy from the sun is converted to the chemical energy of sugars.

10. Light Reactions
Light-dependent reactions occur on the thylakoid membranes.
Light and water are required for this process.
Energy storage molecules are formed. (ATP and NADPH)
Oxygen gas is made as a waste product.

12. Dark Reactions Dark reactions (light-independent) occur in the stroma.
Carbon dioxide is “fixed” into the sugar glucose.
ATP and NADPH molecules created during the light reactions power the production of this glucose.

14. EQUATION FOR PHOTOSYNTHESIS
WATER
OXYGEN
6CO2 +
6H2O +
ENERGY
C6H12O6 +
6O2
CARBON DIOXIDE
GLUCOSE

15. Chemical Energy & Food One gram of glucose = 3811 calories
1 calorie = amount of energy needed to heat 1 gram of water 1 degree Celsius
Food calories are measured in Calories where 1 Calorie = 1000 calories.

16. Oxygen + Glucose  Carbon Dioxide + Water + Energy
Cellular Respiration
Cellular Respiration is the process that releases energy by breaking down food molecules in the presence of oxygen.
6O2 + C6H12O6  6CO2 + 6H2O + Energy
Oxygen + Glucose  Carbon Dioxide + Water + Energy

17. EQUATION FOR RESPIRATION
CARBON DIOXIDE
ATP
GLUCOSE
C6H12O6 +
6O2
6CO2 +
6H2O +
ENERGY
OXYGEN
WATER

18. Glycolysis
Glycolysis is the process in which one molecule of glucose is broken in half, producing two molecules of pyruvic acid.
2 ATP needed to start reaction, 4 ATP are produced thus the net gain is 2 ATP.

21. Anaerobic Cellular Respiration
Fermentation
No Oxygen required= Anaerobic
Releases energy from glucose without the presence of oxygen.
There are two types of fermentation: alcoholic and lactic acid.
Alcoholic fermentation is done by yeasts and some microorganisms. It produces alcohol & Carbon Dioxide
Lactic Acid is produced by muscles during rapid exercise when the body cannot supply enough oxygen.

23. Aerobic Cellular Respiration
Oxygen required=aerobic
2 more sets of reactions which occur in a specialized structure within the cell called the mitochondria
1. Kreb’s Cycle
2. Electron Transport Chain

24. The Krebs Cycle
During the Krebs Cycle, pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions.
Citric Acid is created in this cycle thus giving it the nickname Citric Acid cycle.
Net ATP Production is 2 ATP.

26. Electron Transport Chain
The electron transport chain uses the high-energy electrons from the Krebs Cycle to convert ADP to ATP.
Total ATP 32.

27. Energy Tally 36 ATP for aerobic vs. 2 ATP for anaerobic
Glycolysis ATP
Kreb’s ATP
Electron Transport 32 ATP
36 ATP
Anaerobic organisms can’t be too energetic but are important for global recycling of carbon

28. Energy & Exercise
Quick energy (anaerobic) – Lactic Acid fermentation is used to get quick energy and gives off lactic acid as a by product, thus the muscle pain.
Long-Term Energy (aerobic) – Use cellular respiration to produce energy. Exercising or activities that last for at least 15 to 20 minutes. Best form for weight control.

30. Overview of photosynthesis and respiration
SUN
RADIANT ENERGY
CELL
ACTIVITIES
PHOTOSYNTHESIS
RESPIRATION
GLUCOSE
ATP(ENERGY)

31. Photosynthesis & Respiration
Comparing
Photosynthesis & Respiration
Photosynthesis
Cellular Respiration
Function
Energy Storage
Energy Release
Location
Chloroplasts
Mitochondria
Reactants
CO2 and H2O
C6H12O6 and O2
Products
Equation
6CO2 + 6H2O  C6H12O6 + 6O2
C6H12O6 + 6O2
6CO2 + 6H2O