1. Energy in a Cell Photosynthesis & Cellular Respiration

2. Overview of Photosynthesis and Respiration
SUN
RADIANT ENERGY
CELL
ACTIVITIES
PHOTOSYNTHESIS
RESPIRATION
GLUCOSE
ATP (ENERGY)

3. Cell Energy Energy is essential for life
Active transport, cell division, flagella movement, protein production
Some capture energy from light or chemicals
Autotrophs
Others eat those that capture energy
heterotrophs

4. So Where Is Energy Found?
Energy is stored in chemical bonds of ATP
Adenosine Triphosphate (ATP)
Adenosine molecule with three phosphate groups
Energy carrier molecule of the cell

5. Question…?
How do you release the energy stored in the bonds?

6. Answer
Break the bond!

7. Energy is Stored in the BOND!

8. Forming and Breaking Down ATP
Adenosine monophosphate (AMP)
Adenosine diphosphate (ADP)
Adenosine triphosphate (ATP)
ATP  ADP + P + Energy
Energy + P + ADP  ATP

9. What is Photosynthesis?
The process of photosynthesis is a chemical reaction.
It is the most important chemical reaction on our planet.

10. What is the Equation for the Chemical Reaction of Photosynthesis in WORDS?

11. What is the Equation for the Chemical Reaction of Photosynthesis (SYMBOLS)?

12. Describe Photosynthesis
The process of changing light energy to chemical energy
Energy stored as sugar
Occurs in plants and some algae
Plants need light energy, CO2, and H2O
Takes place in the chloroplasts, using chlorophyll, the green pigment in plants

13. What Happens During Photosynthesis – An Overview
Plants capture light energy and use that energy to make glucose
Sunlight provides the energy needed by chlorophyll to change molecules of carbon dioxide and water into glucose
Oxygen is also released in this reaction

14. What Happens During Photosynthesis – More Specific?
Carbon dioxide enters the leaf through holes called stomata
CO2 combines with the stored energy in the chloroplasts through a chemical reaction to make glucose
The sugar is moved through tubes in the leaf to the roots, stems and fruits of the plants
Some of the sugar is used right away by the plant for energy; some is stored as starch; and some is built into plant tissue

15. The Importance… The Big Two Reasons:
1. We cannot make our own food (glucose, energy), we must get our food from plants.
(Plants are the first step in the food chain.)
2. The oxygen released during photosynthesis is necessary for all living things.

16. Trapping Energy from Sunlight
Photosynthesis
Process that uses the sun’s energy to make simple sugars
Glucose, Fructose, Galactose
Light-dependent Reactions
Convert light into chemical energy (ATP)
Light-independent Reactions (Calvin Cycle)
Fueled by ATP
Produce simple sugars
6CO2 + 6H2O  C6H12O6 + 6O2

17. Chloroplasts and Pigments
Molecules in thylakoid membranes that absorb specific wavelengths of sunlight
Cholorophyll is the most common pigment
Absorbs most wavelengths of light except for green.

18. Light-Dependent Reactions
Light energy hits thylakoid discs
Electrons are charged with energy and EXCITED! HOT!
Electron Transport Chain
Electrons travel through a series of proteins
Lose energy which is used to make ADP into ATP
Electrons reach a second photosystem (pigments) and are recharged
Travel down a 2nd transport chain

19. Light-Dependent Reactions
Electrons, at end of chain, transferred to a carrier molecule (NADP+ )
NADP+ + electron + H = NADPH
Carries the electron to the Stroma
NADPH used in Calvin Cycle

20. Restoring Electrons Photolysis (lysis = to break down) Chemiosmosis
Reaction where water is split H20  O + 2H+ + 2e
Oxygen released into air (O2)
The electrons are used by chlorophyll
Hydrogen ions are taken to thylakoid discs
Chemiosmosis
H+ moves across membrane due to concentration gradient
Creates charge / energy = used to make ATP

21. Light-Independent Reactions The DARK Reactions
Calvin Cycle
Series of reactions that uses CO2 to create sugars
Takes place in the Stroma
Named for Melvin Calvin

23. Summary of Calvin Cycle
1. Co2 combines with RuBP to form 2 molecules of PGA
2. Each molecule of PGA is converted into a molecule of PGAL
3. Most of PGAL is converted back into RuBP, but some PGAL can be used to make a variety of organic compounds

24. The Leaf

25. What is this?
Guess?

26. A Summary of Photosynthesis+
H2O
CO2
Energy
ATP and
NADPH2
Which splits
water
Light is Adsorbed By
Chlorophyll
Calvin Cycle
ADP
NADP
Chloroplast
Used Energy and is recycled. O2 +
C6H12O6
Light Reaction
Dark Reaction

27. What is Cellular Respiration?
The release of chemical energy for use by cells.
Once the energy that was in sunlight is changed into chemical energy by photosynthesis, an organism has to transform the chemical energy into a a form that can be used by the organism.
This process is cellular respiration.

28. Describe Cellular Respiration
1. The breakdown of glucose molecules to release energy
2. Takes place in all living things
3. Is a step by step process

29. What is the chemical equation for cellular respiration?

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

31. Do You See The Relationship with Photosynthesis!?
Respiration has the SAME formula as photosynthesis except it is backwards!

32. Cellular Respiration
Process by which mitochondria break down food molecules to produce ATP
Three Stages
Glycolysis – Anaerobic
Citric Acid Cycle – Aerobic
Electron Transport Chain - Aerobic

33. Glycolysis Net gain = 2 ATP
Glucose gets broken into two three carbon pyruvic acids
2 ATP used to start this reaction
Reaction produces 4 ATP
Net gain = 2 ATP
NAD+ = electron carrier = NADH when it accepts two electrons

34. Pyruvic molecules move into Mitochondria
IF OXYGEN IS PRESENT then the Citric Acid cycle takes place
Pyruvic acid loses one carbon (CO2)
Combines with Coenzyme A to create Acetyl-CoA

35. Citric Acid Cycle (Krebs)

36. Electron Transport Chain

37. Fermentation Net Gain = 2 ATP
Times when there is not enough oxygen to do Citric Acid Cycle
Net Gain = 2 ATP
Two major types
Lactic Acid
Alcoholic

38. Respiration CYTOPLASM GLYCOLOSIS HAPPENS HERE! CO2 IS RELEASED
PROTEINS
CARBO’S
(SUGARS)
FATS
(LIPIDS)
GLUCOSE
C6H12O6
AMINO
ACIDS
MAKES
2 ATPS
GLYCOLOSIS
IN CYTOPLASM
NO OXYGEN!
ATP TOTALS
GLYCOLOSIS=2
RESPIRATION=34
BOTH=36!
PYRUVIC
ACID
CO2 IS RELEASED
ACETYL-CoA
O2 ENTERS HERE
KREBS CYCLE
AND
ELECTRON
TANSPORT
MAKES
34 ATPS
MITOCHONDRIA RESPIRATION HAPPENS IN THIS ORGANELLE!

39. Compare and Contrast Photosynthesis & Cellular Respiration

41. Photosynthesis & Cellular Respiration are Interconnected

42. The End