1. Ch.8 – Cellular Energy
8.1 – How organisms obtain energy
Energy represents the capacity to do work. Cells must acquire energy from their environment. In life, energy transformations consist primarily of movement of molecules and changes in chemical bonds.
Metabolism is the set of chemical reactions that happen in living organisms to maintain life
2 Types
Catabolism Releasing energy by breaking down of larger molecules into smaller ones Digestion
Anabolism Storing energy by creating larger molecules from smaller ones. Creating body fat

2. 8.1 – How organisms obtain energy
Ch.8 – Cellular Energy
8.1 – How organisms obtain energy
All living cells use adenosine triphosphate (ATP) for capture, transfer, and storage of energy.
Each cell needs millions of ATP molecules per second in order to drive its biochemical machinery

3. Autotrophs Heterotrophs
Ch.8 – Cellular Energy
8.1 – How organisms obtain energy
Autotrophs
are able to create glucose from inorganic substances.
That glucose is broken down to form ATP molecules
Heterotrophs
obtain glucose from digesting other living things.
That glucose is broken down to form ATP molecules
Autotrophs
Heterotrophs

4. Carbon Dioxide + Water Light Glucose + Oxygen
Ch.8 – Cellular Energy
8.2 – Photosynthesis
The story of how living things make ATP starts with…
Carbon Dioxide + Water Light Glucose + Oxygen
6 CO2 + 6 H2O Light C6H12O6 + 6 O2

5. Ch.8 – Cellular Energy
8.2 – Photosynthesis

6. Ch.8 – Cellular Energy
8.2 – Photosynthesis
3PGA
Glucose
The light reactions (in the thylakoids) split water, release O2, produce ATP, and form NADPH
The Calvin cycle (in the stroma) forms sugar from CO2, using ATP and NADPH
The Calvin cycle begins with carbon fixation, incorporating CO2 into organic molecules

7. 8.2 – Photosynthesis Ch.8 – Cellular Energy Light Reaction Movie
Red light is very important to plant reproduction. Phytochrome pigments absorb the red and far red portions of the light spectrum and regulate seed germination, root development, tuber and bulb formation, dormancy, flowering and fruit production. Therefore, red light is essential for stimulation of flowering and fruiting.   Blue light stimulates Chlorophyll production more than any other colour, encouraging thick leaves, strong stems and compact vegetative growth. Chlorophyll absorbs blue and red light and transmits the energy to a pigment-based electron transport chain. The energy is ultimately used to produce high-energy chemical bonds that can be used for a range of biochemical transformations, including fixation of carbon-dioxide into sugars. Carotenoids, the yellow-orange pigment in plants, absorb blue light and control leaf fall and fruit ripening. Riboflavin (Vitamin B2) absorbs violet light and influences "phototropism", the movement of plant foliage in response to light.

8. Light energy is used to split an H2O molecule When H2O splits
Ch.8 – Cellular Energy
8.2 – Photosynthesis
Photosystem II
Light energy is used to split an H2O molecule
When H2O splits
O2 is released
protons (H+ ions) stay in the thylakoid space &
an activated electron enters the electron transport chain.

9. Electron Transport Chain
Ch.8 – Cellular Energy
8.2 – Photosynthesis
Electron Transport Chain
Electrons are moved through the thlakoid membrane and more protons are pumped into the thylakoid space

10. Light reenergizes the electrons
Ch.8 – Cellular Energy
8.2 – Photosynthesis
Photosystem I
Light reenergizes the electrons
The reenergized electon is transferred to
NADP+ Reductase to form an NADPH from NADP+

11. 8.2 – Photosynthesis Chemiosmosis
Ch.8 – Cellular Energy
8.2 – Photosynthesis
Chemiosmosis
Protons build up in the thylakoid space and create a concentration gradient
Protons then move across the thylakoid membrane through ATP synthase which causes ADP to convert to ATP
Light Reactions Animation

12. Light Independent or Calvin Cycle
Ch.8 – Cellular Energy
8.2 – Photosynthesis
What is the basic formula of photosynthesis?
How did plants acquire photosynthesis in evolution? Name three features of chloroplasts that are indicative of their origin. (It is referred to as endosymbiosis or the endosymbiotic theory) Click
Photosynthesis can be divided in two different processes. What are these processes? What are their products and reactants?
Oxygen is released during photosynthetic light reactions. Where is this oxygen coming from?
Name
Reactants
Products
Light Dependant
Light & H2O
(NADP+ & ADP) O2
(NADPH & ATP)
Light Independent or Calvin Cycle
CO2
Glucose
The splitting of H2O in Photosystem II

13. Energized e- are transferred to the enzyme NADP+ Reductase
Ch.8 – Cellular Energy
8.2 – Photosynthesis
Outside
There is a much higher concentration of H+ ions in the thylakoid. This creates an acidic environment and thus a lower pH than in the stroma of the chloroplasts
What is the driving force for ATP synthesis at the ATP synthase multi-protein complex?
Where do you find a higher pH value, inside or outside of the thylakoid?
7. Which process creates NADPH from NADP+?
The proton concentration gradient created by splitting water and the electron transport chain
Photosystem I
Energized e- are transferred to the enzyme NADP+ Reductase

14. Ch.8 – Cellular Energy
8.2 – Photosynthesis

15. The Calvin Cycle (light independent reactions or the dark reactions)
Ch.8 – Cellular Energy
8.2 – Photosynthesis
The Calvin Cycle (light independent reactions or the dark reactions)
3PGA
Glucose

16. 3 CO2 combine with 3 5-C compounds to form 6 3-C compounds called
Ch.8 – Cellular Energy
8.2 – Photosynthesis
Carbon Fixation
3 CO2 combine with 3 5-C compounds to form 6 3-C compounds called
3-PGA

17. Energy from ATP and NADPH is used to form
Ch.8 – Cellular Energy
8.2 – Photosynthesis
Reduction
Energy from ATP and NADPH is used to form
6 G3P molecules
(high energy molecules)
From the 6 PGA molecules
1 G3P molecule leaves the cycle to form glucose, fructose starches, etc.

18. ATP and the enzyme rubisco convert the 5 G3P to 3 RuBP
Ch.8 – Cellular Energy
8.2 – Photosynthesis
Regeneration
ATP and the enzyme rubisco convert the 5 G3P to 3 RuBP
These molecules are then ready to bond with 3 more CO2
Calvin Cycle Animation

19. Cellular Respiration 8.3 - Cellular respiration Aerobic Respiration
Ch.8 – Cellular Energy
8.3 - Cellular respiration
Cellular Respiration
Aerobic Respiration
requires O2 to make ATP from the energy stored in glucose
Glucose + Oxygen  Energy + Carbon Dioxide + Water
C6H12O6 + 6 O2  36/38 ATP + 6 CO2 + 6 H2O

20. 8.3 - Cellular respiration
Ch.8 – Cellular Energy
8.3 - Cellular respiration

21. Electron Transport Chain Oxidative phosphorylation
Ch.8 – Cellular Energy
8.3 - Cellular respiration
The 3 Processes of cellular respiration O2 2 3 1
Electron Transport Chain
Oxidative phosphorylation
or Krebs Cycle
H2O
CO2 32 Or 34 2 2

22. Glycolysis Net ATP = 2 8.3 - Cellular respiration
Ch.8 – Cellular Energy
8.3 - Cellular respiration
Glycolysis
(“splitting of sugar”) breaks down glucose into two molecules of pyruvate
Glycolysis occurs in the cytoplasm and has two major phases:
-Energy investment phase
-Energy payoff phase
Net ATP = 2

23. It takes place in the matrix of the mitochondria
Ch.8 – Cellular Energy
8.3 - Cellular respiration
Citric Acid Cycle or
Krebs Cycle
Before the citric acid cycle can begin, pyruvate must be converted to Acetyl CoA
It takes place in the matrix of the mitochondria

24. forming citric acid (citrate)
Ch.8 – Cellular Energy
8.3 - Cellular respiration
Citric Acid Cycle or
Krebs Cycle
The acetyl group of acetyl CoA joins the cycle by combining with the 4-C compound,
oxaloacetate,
forming citric acid (citrate)

25. The next seven steps decompose the citrate back to oxaloacetate
Ch.8 – Cellular Energy
8.3 - Cellular respiration
Citric Acid Cycle or
Krebs Cycle
The next seven steps decompose the citrate back to oxaloacetate
The NADH and FADH2 produced by the cycle send electrons to the electron transport chain

26. 8.3 - Cellular respiration
Ch.8 – Cellular Energy
8.3 - Cellular respiration
e- from NADH & FADH2 pass through protein complexes in the cristae (inner membrane)
This causes H+ to be pumped out of the matrix

27. 8.3 - Cellular respiration
Ch.8 – Cellular Energy
8.3 - Cellular respiration
To give you an idea of how much ATP we require to survive…
We take in about 2 x 1020 molecules of O2 per breath
200,000,000,000,000,000,000
O2 diffuses into the matrix and bonds with the e- passing through the transport chain.
H+ diffuses through ATP synthase back into the matrix (chemiosmosis) creating ATP (phosphorilation)

28. Anaerobic Respiration or
Ch.8 – Cellular Energy
8.3 - Cellular respiration
Making energy when there is no oxygen
Anaerobic Respiration or
Fermentation
It is essentially a cell just relying on glycolysis for its energy needs
Only produces 2 ATP per glucose molecule (not the 36 or 38 that aerobic respiration can create)
Other molecules are created through reactions that provide the NAD+ needed for glycolysis to occur
ATP can be created much faster than with aerobic respiration (just in smaller quantities)

29. Lactic Acid Alcoholic Fermentation Fermentation -O Glucose 2 ATP 4 ATP
2 Pyruvic Acids
CH3-C-C-OH =O -O
Lactic Acid
Fermentation
Alcoholic
Fermentation
CO2
2 Acetylaldehydes
CH3-CH -O
2 Lactic Acids
CH3-CH-C-OH
-OH =O
2 Ethanols
CH3-CH2-OH

30. Used by some fungi and bacteria & is used to make cheese and yogurt
Glucose
2 ATP
4 ATP
2 Pyruvic Acids
CH3-C-C-OH =O -O
Lactic Acid
Fermentation
Used by some fungi and bacteria & is used to make cheese and yogurt
Human muscle cells use lactic acid fermentation to generate ATP when O2 is scarce
2 Lactic Acids
CH3-CH-C-OH
-OH =O

31. Used by some fungi and bacteria & is used to make cheese and yogurt
Glucose
2 ATP
4 ATP
2 Pyruvic Acids
CH3-C-C-OH =O -O
Lactic Acid
Fermentation
Used by some fungi and bacteria & is used to make cheese and yogurt
Human muscle cells use lactic acid fermentation to generate ATP when O2 is scarce
2 Lactic Acids
CH3-CH-C-OH
-OH =O

32. Alcoholic Fermentation
Glucose
2ATP
4ATP
2 Pyruvic Acids
CH3-C-C-OH =O -O
Alcoholic
Fermentation
Used by yeast and some bacteria & is used in brewing, winemaking, and baking
CO2
2 Acetylaldehydes
CH3-CH -O
2 Ethanols
CH3-CH2-OH