1. Photosynthesis
Unit 6
Unit 6 Packets and “What’s in a Leaf?” POGILs are at the desks already – grab one. Turn in completed Winter Break assignments and be ready to get some notes!

2. Unit 6 Overview
Day 1 – Notes on Photosynthesis and “What’s in a leaf?” POGIL
Day 2 – Photosynthesis GIZMO and set up Photosynthesis Research Notebook/LAB
Day 3- Carry out Photosynthesis Lab (must bring notebooks and dress properly)
Day 4 – Quiz on Photosynthesis and continue to work in class on lab
Day 5 – Lab Notebooks Due, take Cell Respiration notes in class
Day 6 – Compare and Contrast Photosynthesis and Cell Respiration. Complete POGIL in Class and review for test.
Day 7 – Unit 6 Test
Day 8 – SOL Diagnostic (Not Graded)

3. Autotrophs & Heterotrophs
Autotrophs – organisms use can make their own food
Some autotrophs capture light energy from the sun in the process of photosynthesis
Heterotrophs – obtain energy from the foods they consume

4. ATP & Energy Structure of ATP
ATP (Adenosine Triphosphate) – shuttles energy for cells
ATP is composed of ribose (a sugar), adenine (a nitrogenous base), and three phosphate groups

5. ATP & Energy
The bond between the terminal phosphate groups of ATP’s can be broken, releasing organic phosphate and leaving ADP (adenosine diphosphate).
Energy is released from ATP when the terminal phosphate bond is broken.
This release of energy comes from the chemical change to a state of lower free energy (stabilizing), not from the phosphate bonds themselves.

6. ATP & Glucose ATP is not good for storing energy for a long time.
Cells only have a small amount of ATP.
One Glucose can store more than 90 times more energy than one ATP.
Cells store glucose, and use glucose to regenerate ATP as needed (cellular respiration).

7. *Photosynthesis – process of capturing light energy from the sun to convert water & CO2 into oxygen and high energy carbohydrates (food, ex: glucose, starch, & other sugars)

8. Investigating Photosynthesis
Van Helmont’s Experiment – do plant’s grow by taking material from the soil?
Found mass of dry soil
Planted a seedling, watered it at regular intervals until it grew to a mass of 75kg.
Found mass of soil to be unchanged
Concluded the mass the plant gained came from the water he added.
Partially correct, but did not determine where the carbon in the carbohydrate comes from

10. Priestley’s Experiment – oxygen is produced by plants
Determined that oxygen was required to keep a flame lit/burning.
Removed oxygen from a jar by placing a lit candle under it until the flame went out.
Then placed a sprig of mint in the jar (empty of oxygen)
After a few days, he found he could relight a candle in this jar and it would remain lit for a while!

12. Jan Ingenhousz – light is essential to photosynthesis!
Showed the effect observed by Priestley occurred only when the plant is exposed to light!
Together, Priestly and Ingenhousz showed the plants need light and water to produce oxygen.

13. Photosynthesis Basics – occurs in the chloroplasts of plants, protists, and some bacteria cells.
Chloroplast – organelle where photosynthesis occurs
Surrounded by 2 membranes.
Thylakoid – flattened sac made of membrane inside the chloroplast
Granum – stack of multiple thylakoids
Stroma – fluid that surrounds the grana and fills the chloroplast

15. B. Pigments – compound that absorbs light
1. Chlorophyll – pigment on thylakoid membrane that absorbs light for photosynthesis
Chlorophyll a – absorbs less blue and more red light; directly absorbs sunlight
Chlorophyll b – absorbs more blue and less red light; helps chlorophyll a absorb light
Both chlorophyll a and b reflect green light
Caretenoid – another pigment that absorbs blue and green light, but not orange; also helps chlorophyl a absorb light.

16. **Equations are also the reverse!
C. Photosynthesis is chemically the opposite of Respiration.
Respiration Photosynthesis
Uses glucose to make ATP 1st converts light to ATP
2nd uses ATP to make glucose
**Equations are also the reverse!

17. NADPH
As chlorophyll absorb sunlight, their electrons become excited (gain a lot of energy).
These high energy electrons require a special carrier called NADP+
NADP+ holds and carries 2 high energy electrons, along with a H+ ion to become NADPH

18. Light-Dependent Reactions – first step, converts sunlight to ATP
Occurs on the thylakoid membrane & is made of PHOTOSYSTEM I and PHOTOSYTEM II
Light is absorbed by chlorophyll in PHOTOSYSTEM II.

19. The light energy provides electrons for the Electron Transport Chain (chain of proteins).
Electrons in PHOTOSYSTEM II split water (H+ & O2 are released).
Some H+ is added to NADP+ and produces NADPH as electrons move from PHOTOSYSTEM II to the ETC
The O2 is released to the atmosphere.
A photon of light is absorbed by chlorophyll in PHOTOSYSTEM I and combines with electrons from ETC

21. *Chemiosmosis and the ETC happen at the same time!!!
Also happens on the membrane of the thylakoids.
Electrons from PHOTOSYSTEM II provide the energy for pumping H+ into the thylakoids
Rest of the H+ (from the splitting of water) turn ATP Synthase proteins (like a turbine) to make ATP.
*Chemiosmosis and the ETC happen at the
same time!!!
* ATP and NADPH are products of the Light
Reactions

24. Uses ATP & NADPH to make Glucose Cycles 6 times to make 1 Glucose
Calvin Cycle – the 2nd step of photosynthesis. Also called the Light-independent Reactions (used to be called Dark Reactions), as light does not play any direct role.
Uses ATP & NADPH to make Glucose
Occurs in the Stroma
Cycles 6 times to make 1 Glucose

25. Steps of the Calvin Cycle
RuBP (carbohydrate in plants) reacts with NADPH, 6 CO2 (from the atmosphere), and ATP to make Glucose.
Catalyzed by the enzyme Rubisco
In the final step, RuBP is remade so the cycle can occur again.
Overall, uses 6 CO2 to make 1 glucose and cycles 6 times.

27. Factors Affecting Photosynthesis
Water – is a needed raw material; shortage of water slows or even stops photosynthesis
Temperature – photosynthesis relies on enzymes, which only function between 0oC and 35oC
Intensity of Light – up to a specific level, as light intensity increases, so does the rate of photosynthesis

28. Amoeba Sister Video!

29. Glycolysis & Fermentation
Harvesting Chemical Energy
Cellular Respiration – the break down of organic compounds (food, glucose, etc.) in cells to make energy, ATP molecules
C6H12O O2  6CO H2O + Energy

30. Glycolsysis
Biochemical pathway that always starts cellular respiration!!!
Does produce a small amount of ATP.
Other products can follow two other pathways, depending on whether oxygen is present not.

31. Glycolysis ATP Oxygen Absent Oxygen Present Fermentation (anaerobic)
Aerobic Respiration

32. Cellular Respiration Overview
Carbon
Glucose
Electron
Dioxide
(C6H12O2) →
Glycolysis
Krebs
Transport
(CO2) +
Cycle
Chain
Oxygen
Water
(O2)
(H20)

34. Two (2) Types of Cellular Respiration
Fermentation– respiration without oxygen
Can also be called anaerobic respiration
Aerobic Respiration – respiration with oxygen
Aerobic = “with oxygen” like aerobic workouts
Anaerobic = “without oxygen” like weightlifting workouts

35. II. Glycolysis Basics of Glycolysis glyco: sugar lysis: break up
Begins to break down glucose & releases a small amount of energy (ATP)
Occurs in the cytoplasm.
All types of cellular respiration begin with glycolysis!!!!!!!!!!

36. Major events in Glycolysis
Start with (invest) 1 glucose, 2 NAD+, and 2 ATP molecules.
Glucose, a 6-carbon molecule, is split into 2 PGAL, or glyceraldehyde-3-phosphate, molecules (each a 3-carbon molecule).
Hydrogens are transferred from the 2 PGAL molecules to the 2 NAD+ molecules. This produces 2 NADH molecules.
4 ATP molecules are then produced (2 ATP overall). This also produces 2 pyruvic acid molecules.
Ends with 2 pyruvic acid, 2 ATP, 2 NADH molecules.

37. Glycolysis

38. III. Fermentation Basics Also known as Anaerobic Respiration
Does not make any ATP!
Does remake NAD+, which goes back through Glycolysis to make 2 more ATP.

39. 2 Types of Fermentation Alcoholic Fermentation
A CO2 molecule is removed from each pyruvic acid, creating acetaldehyde.
2 H+ are removed from 2 NADH to make NAD+.
Acetaldehyde is converted into ethyl alcohol by gaining the 2 H+.
NAD+ goes back through glycolysis to make more ATP.

40.   2 ADP  2 P i 2 ATP Glucose Glycolysis 2 Pyruvate 2 NAD 2 NADH
Figure 9.17a
2 ADP  2 P i
2 ATP
Glucose
Glycolysis
2 Pyruvate
2 NAD 
2 NADH
2 CO2 
2 H 
Figure 9.17 Fermentation.
2 Acetaldehyde
2 Ethanol
(a) Alcohol fermentation

41. Lactic Acid Fermentation
2 H+ are removed from 2 NADH to make NAD+.
Pyruvic acid is converted into lactic acid by gaining the 2 H+.
NAD+ goes back through glycolysis to make more ATP.

42. (b) Lactic acid fermentation 2 Lactate 2 Pyruvate 2 NADH Glucose
Glycolysis
2 ADP  2 P i
2 ATP
2 NAD 
2 H
Figure 9.17 Fermentation.

44. Mitochondria Review Structure Surrounded by a double membrane
The 2nd, inner membrane, is highly folded to increase surface area. Each fold is called a cristae
The very interior of the mitochondria is called the mitochondrial matrix.

45. IV. Cellular Respiration (aerobic)
Basics
Cellular Respiration requires oxygen (O2)!
Produces nearly 20 times more ATP than glycolysis alone.
Begins with Glycolysis, followed by the Kreb’s Cycle, the Electron Transport Chain, and Chemiosmosis.

46. Pyruvic acid is converted into Acetyl CoA.
Glycolysis
Converts glucose into 2 pyruvic acids.
Makes 2 NADH and a net of 2 ATP.
Occurs in the cytoplasm
Pyruvic acid is converted into Acetyl CoA.
The 2 Pyruvic Acids pass through both mitochondrial membranes into the mitochondrial matrix.
As this happens, the 2 pyruvic acids reacts with a molecule called coenzyme A to form Acetyl CoA.
2 NADH’s and CO2 are produced.

48. Kreb’s Cycle
Each Acetyl CoA is broken down to make 1 ATP, 3 NADH, and 1 FADH2.
1st product is remade in the last step, so the Kreb’s Cycle can happen again.
Remember, there are 2 Acetyl CoA’s, so the Kreb’s cycle will happen twice.
Our totals are therefore: 2 ATP, 6 NADH, and 2 FADH2.

49. Citric acid cycle Acetyl CoA Oxaloacetate Malate Citrate Isocitrate
NADH 1
Acetyl CoA
Citrate
Isocitrate
-Ketoglutarate
Succinyl CoA
Succinate
Fumarate
Malate
Citric acid cycle
NAD
FADH2
ATP
+ H
H2O
ADP
GTP
GDP
P i
FAD 3 2 4 5 6 7 8
CoA-SH
CO2
Oxaloacetate
Figure 9.12 A closer look at the citric acid cycle.

50. Electron Transport Chain
Occurs across the inner membrane of the mitochondria (cristae).
H+ ions are released from NADH and FADH2 into the mitochondrial matrix.
The electrons in the hydrogen atoms are at a high energy level!
The high energy electrons are passed along a series of molecules called the Electron Transport Chain.

51. Electron Transport Chain (cont.)
As the electrons move from molecule to molecule, they lose some of their energy.
This energy pumps H+ out of the mitochondrial matrix, into the space between the two mitochondrial membranes.
A high concentration of H+ builds up in this space.

52. Electron Transport Chain

53. Chemiosmosis
H+ ions diffuse from the high area of concentration made in between the 2 mitochondrial membranes to the low are in the matrix.
Specifically the H+ ions move through a protein called ATP Synthase.
As H+ ions move through ATP Synthase, ATP is made!
32 ATP are made in chemiosmosis.
The H+ ions then combine with oxygen to form water.

54. Electron Transport Chain

55. Summary of Cellular Respiration
Total ATP made aerobically: 36 ATP’s Glycolysis = 2 Kreb’s Cycle = 2 ETC/Chemiosmosis = 32