1. I. PHOTOSYNTHESIS

2. Photosynthesis 6CO2 + 6H2O  C6H12O6 + 6O2
Photosynthesis: light energy is converted into chemical energy
Carbon dioxide (CO2) requiring process that uses light energy (photons) and water (H2O) to produce organic macromolecules (glucose).
6CO H2O  C6H12O O2
glucose
SUN
light energy

3. Photosynthesis A two step anabolic reaction
Light reactions – light energy converted into ATP and NADPH
Calvin cycle – energy stored in ATP and NADPH is used to fix CO2 into organic compounds

4. II. Two Natures of Light
Light acts like two things
A wave
A particle

5. Wave Nature
Light is just a small sliver of something called electromagnetic radiation
A form of energy that exhibits wavelike behavior as it travels through space
Includes:
Visible light
Microwaves
X-rays
Radio waves
UV rays
Gamma rays

6. III. Electromagnetic Spectrum
Sunlight contains a continuous range of wavelengths

7. Electromagnetic Spectrum
Of course we know from getting tan and sunburnt that light isn’t the only electromagnetic radiation the sun emits

8. Particle Nature Einstein jumps in:
He states that a beam of light can be thought of as a stream of tiny particles, or bundles of energy which he called photons
A photon is a particle of electromagnetic radiation with no mass that carries a quantum of energy

9. Question:
What do we call organisms in which photosynthesis take place?

10. Autotrophs Ex. plants, blue-green algae Autotrophs: self-producers.
What organelle in autotroph
cells is responsible for
photosynthesis?

11. Chloroplast Organelle where photosynthesis takes place. Stroma
Outer Membrane
Thylakoid
Granum (grana)
Inner Membrane

12. Thylakoid
Thylakoid Membrane
Granum
Thylakoid Space

13. Question:
Why are plants green?

14. III. Chlorophyll Molecules
Chlorophyll a and b
Located in the thylakoid membranes
Chlorophyll pigments harvest light energy by absorbing certain wavelengths.
blue-420 nm and red-660 nm are most important
Plants are green because the green wavelengths are reflected, not absorbed.

15. Absorption of Chlorophyll
violet blue green yellow orange red
Absorption
wavelength

16. Question:
During the fall, what causes the leaves to change colors?

17. Fall Colors
In addition to the chlorophyll pigments, there are other accessory pigments present.
During the fall, the green chlorophyll pigments are greatly reduced revealing the other accessory pigments.
Carotenoids are pigments that are either red or yellow.

18. IV. Breakdown of Photosynthesis
Two main parts (reactions).
1. Light Reaction (the electron flow)
There are two reactions dependent on light.
Produces energy from light (photons = solar energy) in the form of ATP and NADPH

19. 1. Light Reaction (Electron Flow)
Occurs in the thylakoid membranes
Five main steps

20. Step 1 Occurs in the thylakoid membrane.
Light energy is captured by Photosystem II (PSII)
Contains chlorophyll a
Light is “captured” = electrons are excited

21. Step 2 & 3 electrons now have enough energy to leave chlorophyll a
in order to leave there has to be a molecule to accept them
this is called the primary electron acceptor

22. Step 2 & 3
the primary electron acceptor donates the electron to the first of a series of molecules known as the Electron Transport Chain (ETC)
each time it transfers an electron, energy is lost and used to pump a proton - H+ - into the thylakoid space

23. Step 4
light is also captured by chlorophyll a in PSI and it sends excited electrons down the ETC as well as electrons it received that had traveled through PSII ETC

24. Step 5
this ETC is on the stroma side of the thylakoid membrane and is used to combine electrons with H+ and NADP+ to produce a molecule of NADPH

25. When is O2 generated by photosynthetic organisms?
The original e- that left PSII must be replaced. PSII gets its electrons when an enzyme splits H2O molecules from the inside of the thylakoid.

26. Chemiosmosis
the movement of ions across a selectively permeable membrane, down their electrochemical gradient
powers ATP synthesis
located in the thylakoid membranes
ETC and ATP synthase (enzyme) required to make ATP

27. Proton Gradient High [H+] Low [H+]
There’s a H+ concentration gradient across the thylakoid membrane.
the concentration of H+ is higher on the inside than the outside.
High [H+]
Low [H+]

28. Generation of ATP High [H+] Low [H+]
ATP synthase uses the potential energy (PE) of this gradient to add a phosphate to ADP, creating ATP, when H+ moves through the ATP synthase complex.
So, ATP synthase converts potential energy into stored chemical energy in the form of the newly formed bond in ATP.
High [H+]
Low [H+]

29. Generation of NADPH High [H+] Low [H+]
some of these H+ that are moving into the stroma will then be used to generate NADPH.
Both ATP and NADPH will then be used in the next set of reactions known as the Calvin cycle (carbon fixation).
High [H+]
Low [H+]

30. IV. Breakdown of Photosynthesis
2. Calvin cycle or
dark reaction or
carbon fixation or
C3 fixation
These reactions do not directly require light
Uses energy (ATP and NADPH) from light rxn to make organic molecules, specifically sugar (glucose).

31. Calvin Cycle

32. Calvin Cycle includes the process of Carbon Fixation
occurs in the stroma
breaks the chemical bonds of ATP and NADPH forming ADP and NADP+ and uses this energy to fix the carbon from CO2 into organic compounds
an important organic molecule formed is glucose

33. Recall: Chloroplast Stroma Outer Membrane Thylakoid Granum
Inner Membrane

34. Calvin Cycle (C3 fixation)

35. Calvin Cycle

36. V. Photosynthesis 6CO2 + 6H2O  C6H12O6 + 6O2
When the light reactions and Calvin cycle are combined we get the equation below
6CO H2O  C6H12O O2
Glucose is used as the main organic compound generated in order to show the relationship between photosynthesis and cellular respiration.
glucose
SUN
light energy

37. Cellular Respiration
1. g. Students know the role of the mitochondria in making stored chemical- bond energy available to cells by completing the breakdown of glucose to carbon dioxide.
Mitochondria consist of a matrix where three-carbon fragments originating from carbohydrates are broken down (to CO2 and water) and of the cristae where ATP is produced. Cell respiration occurs in a series of reactions in which fats, proteins, and carbohydrates, mostly glucose, are broken down to produce carbon dioxide, water, and energy. Most of the energy from cell respiration is converted into ATP, a substance that powers most cell activities.
1. i.* Students know how chemiosmotic gradients in the mitochondria and chloroplast store energy for ATP production.
Enzymes called ATP synthase, located within the thylakoid membranes in chloroplasts and cristae membranes in mitochondria, synthesize most ATP within cells. The thylakoid and cristae membranes are impermeable to protons except at pores that are coupled with the ATP synthase. The potential energy of the proton concentration gradient drives ATP synthesis as the protons move through the ATP synthase pores. The proton gradient is established by energy furnished by a flow of electrons passing through the electron transport system located within these membranes. 37

38. VI. Cellular Respiration
Our Objectives:
- Identify the process of how glucose is broken down in the first stage of cellular respiration.
- Identify the steps of aerobic respiration
- Describe how ATP is made in the second stage of cellular respiration.
- Identify the role of fermentation in the second stage of cellular respiration.
- Evaluate the importance of oxygen in aerobic respiration 11 38

39. Cellular Respiration vs Fermentation
(Not in notes)
Cellular Respiration – the transfer of energy from an organic compound into ATP
Fermentation – the breakdown of carbohydrates by enzymes, bacteria, yeasts, or mold in the absence of oxygen 39

40. VI. Cellular Respiration
Fermentation

41. VI. Cellular Respiration
the process in which carbohydrates, mainly glucose, are broken down to make CO2, water, and energy.
this energy will ultimately be stored in ATP
takes place in the cell’s mitochondria 41

42. 42

43. VI. Cellular Respiration
the creation of cellular energy, cellular respiration, has two stages
Glycolysis – the breakdown of glucose 12 43

44. VI. Cellular Respiration
Stage One: Breakdown of Glucose
glycolysis: Glucose is broken down to pyruvate during glycolysis, making some NADH and ATP.
Glycolysis does not require oxygen
an anaerobic process
occurs in the cytoplasm 13 44

45. VI. Cellular Respiration
the creation of cellular energy, cellular respiration, has two stages
Glycolysis – the breakdown of glucose
Aerobic and Anaerobic Respiration – the production of ATP
The second stage of cellular respiration is either aerobic respiration (in the presence of oxygen) or anaerobic respiration (in the absence of oxygen).
A large amount of ATP is made during aerobic respiration.
NAD+ is recycled during the anaerobic process of fermentation. 12 45

46. VI. Cellular Respiration
Aerobic respiration
Two steps:
1. Krebs Cycle (citric acid cycle) – takes place inside mitochondria
-Mainly NADH is produced but also a little ATP to be used in the ETC
- CO2 is generated at two points in this cycle during aerobic respiration. 14 46

47. VI. Cellular Respiration
2. Electron Transport Chain - During aerobic respiration, large amounts of ATP are made in an electron transport chain.
- located in the inner membrane of mitochondria (known as the cristae)
- creates a [H+] gradient
- oxygen is the final acceptor of the electrons in the ETC
- when O2 is the final acceptor this is known as aerobic respiration
Stage Two: Production of ATP 14 47

48. VI. Cellular Respiration
Anaerobic respiration
Fermentation – the breakdown of carbohydrates when oxygen is not present
fermentation follows glycolysis, regenerating NAD+ needed for glycolysis to continue.
this allows ATP to still be generated by glycolysis when aerobic respiration is not possible
generates ethanol and CO2
Lactic Acid Fermentation
In lactic acid fermentation, pyruvate is converted to lactate (lactic acid). 15 48

49. VI. Cellular Respiration cont.
Cellular Respiration is a metabolic process, like burning fuel.
releases much of the energy in food to make ATP
this ATP provides cells with the energy they need to carry out the activities of life.
C6H12O6+O2 CO2 + H2O + ATP
1. g. Students know the role of the mitochondria in making stored chemical-bond energy available to cells by completing the breakdown of glucose to carbon dioxide.
Mitochondria consist of a matrix where three-carbon fragments originating from carbohydrates are broken down (to CO2 and water) and of the cristae where ATP is produced. Cell respiration occurs in a series of reactions in which fats, proteins, and carbohydrates, mostly glucose, are broken down to produce carbon dioxide, water, and energy. Most of the energy from cell respiration is converted into ATP, a substance that powers most cell activities.
1. i.* Students know how chemiosmotic gradients in the mitochondria and chloroplast store energy for ATP production.
Enzymes called ATP synthase, located within the thylakoid membranes in chloroplasts and cristae membranes in mitochondria, synthesize most ATP within cells. The thylakoid and cristae membranes are impermeable to protons except at pores that are coupled with the ATP synthase. The potential energy of the proton concentration gradient drives ATP synthesis as the protons move through the ATP synthase pores. The proton gradient is established by energy furnished by a flow of electrons passing through the electron transport system located within these membranes. 49

50. The connection between photosynthesis and cellular respiration50

51. Review
When oxygen is present, most of the ATP made in cellular respiration is produced by:
A. The Krebs Cycle C. The Mitochondrial ETC
B. Glycolysis D. Fermentation 51