1. Photosynthesis and Respiration
Competency 4

2. Structure of ATP – usable energy of the cell

3. Chemical Cycling Between Photosynthesis and Cellular Respiration

4. THE BASICS OF PHOTOSYNTHESIS
Almost all plants are photosynthetic autotrophs, as are some bacteria and protists
They generate their own organic matter through photosynthesis
(c) Euglena
(d) Cyanobacteria
(b) Kelp
(a) Mosses, ferns, and
flowering plants
Figure 7.2

5. The Overall Equation for Photosynthesis
The reactants and products of the reaction
Light
energy
Water
Carbon
dioxide
Oxygen
gas
Glucose
Unnumbered Figure 7.1

6. Chloroplasts: Sites of Photosynthesis
Photosynthesis occurs in the chloroplasts
Leaves are major site of photosynthesis because they have more chloroplasts
Chlorophyll is the pigment that actually absorbs light energy for photosynthesis

7. Carbon dioxide enters and oxygen exits the leaf through stomata
Water is absorbed by plant’s roots and travels to the the leaves via veins
Chloroplasts
Are found in the cells of the mesophyll (green tissue in the interior of the leaf)
Contain stroma, a thick fluid
Contain thylakoids, membranous disklike sacs
Grana are the stacks that comprise the thylakoids

9. In photosynthesis
Energized electrons are boosted “uphill” and added to carbon dioxide to make sugar
Hydrogen is moved along with the electrons, so the redox process takes the form of hydrogen transfer from water to carbon dioxide
Sunlight provides the energy needed for the chloroplasts to split the water molecules

11. Photosynthesis is a two-step process: Light reaction and Calvin Cycle

12. The light reactions convert solar energy to chemical energy (ATP and NADPH)
Chloroplast
NADP
ADP
+ P
The Calvin cycle makes sugar from carbon dioxide (carbon dioxide is reduced to glucose)
Calvin
cycle
Light
reactions
Figure 7.4

13. Light reaction – Energy in sunlight is trapped, O2 is released, and both ATP and the hydrogen-carrier molecule (NADPH = H) are formed

14. Dark Reaction – ATP, NADPH+H act with CO2 from the atmosphere to form glucose

15. THE CALVIN CYCLE: MAKING SUGAR FROM CARBON DIOXIDE
Functions like a sugar factory within the stroma of the chloroplast
Regenerates the starting material with each turn
The inputs are carbon dioxide from the air and ATP and NADPH produced in the light reactions

16. Calvin cycle 1 4 2 3 Figure 7.13 Input Three CO2 Three RuBP Six 3-PGA
Three ADP
Six ADP + Six
Calvin
cycle 2
Six
Three
Six NADP
Five G3P
Six G3P 3
One G3P
Glucose and
other compounds
Output
Figure 7.13

17. The Overall Equation for Cellular Respiration
A common fuel molecule for cellular respiration is glucose
This is the overall equation for what happens to glucose during cellular respiration
Cellular respiration can make up to 38 ATP molecules for each glucose molecule
Carbon
dioxide
Water
Energy
Glucose
Oxygen
Unnumbered Figure 6.1

18. The Metabolic Pathway of Cellular Respiration
Cellular respiration is an example of a metabolic pathway (metabolism)
A series of chemical reactions in cells
All of the reactions involved in cellular respiration can be grouped into three main stages
Glycolysis
The Krebs cycle
Electron transport

19. A Road Map for Cellular Respiration
Cytosol
Mitochondrion
High-energy
electrons
carried
by NADH
High-energy
electrons carried
mainly by
NADH
Glycolysis 2
Pyruvic
acid
Krebs
Cycle
Electron
Transport
Glucose
Figure 6.7

20. Stage 1: Glycolysis
A molecule of glucose is split into two molecules of pyruvic acid
The enzymes for glycolysis are located outside the mitochondria (dissolved in the cytoplasm)
Glycolysis breaks a six-carbon glucose into two three-carbon molecules
These molecules then donate high energy electrons to NAD+, forming NADH
Oxygen present – next step Krebs Cycle
NO Oxygen present – next step Fermentation

21. Glycolysis makes some ATP directly when enzymes transfer phosphate groups from fuel molecules to ADP
Figure 6.9

22. Stage 2: The Krebs Cycle
The Krebs cycle completes the breakdown of sugar
The enzymes of this stage are found in the liquid inside the mitochondria
In the Krebs cycle, pyruvic acid from glycolysis is first “prepped” into a usable form, Acetyl-CoA
The Krebs cycle extracts the energy of sugar by breaking the acetic acid molecules all the way down to CO2
The cycle uses some of this energy to make ATP
The cycle also forms NADH and FADH2

23. Stage 3: Electron Transport
Electron transport releases the energy your cells need to make the most of their ATP
The molecules of electron transport chains are built into the inner membranes of mitochondria
Converts ADP into ATP
Yields 34 ATP

24. Electron Transport = 34 ATP
ATP Yield
Glycolysis = 2 ATP
Krebs Cycle = 2 ATP
Electron Transport = 34 ATP
TOTAL = 38 ATP

25. Fermentation
When cells release energy in the absence of oxygen (anaerobic respiration)
Produces QUICK energy
Two types:
Alcoholic – produces ethyl alcohol, carbon dioxide, and NAD from pyruvic acid and NADH (yeast and other microorganisms
Lactic Acid – takes place mainly in muscle cells, pyruvic acid is turned into Lactic acid, makes you sore

26. Answers to Matching Game
F: converts light (solar) energy into chemical (glucose) energy
B: photosynthesis
F: Occurs in plants, some protists, and some bacteria
F: occurs in the chloroplasts of eukaryotes
F: green pigment that traps light energy to do photosynthesis
B: chlorophyll
F: stacks of disks in stroma of chloroplast
B: grana
F: fluid b/t double membrane of chloroplast
B: stroma

27. F: each individual disk that makes up the grana in a chloroplast
B: thylakoid
F: thylakoid (disk) of chloroplast is surrounded by membrane called?
B: thylakoid membrane
F: thylakoid disk contains ___ which trap light energy
B: chlorophyll
F: chemical equation for photosynthesis
B: 6CO2 + 6H2O + light  C6H12O6 + 6O2
F: reactants for photosynthesis
B: 6 carbon dioxides, 6 waters, and light
F: products of photosynthesis
B: 1 glucose and 6 oxygens

28. F: once glucose is produced, the glucose leaves the chloroplast and goes to the _
B: mitochondria
F: Oxygen leaves the plant as a waste product through the pores of the leaves
B: stomata
F: 2 stages of photosynthesis
B: light dependent reaction (light reaction) & light independent reaction (dark reaction)
F: stage of photo. that requires light to make ATP
B: light reaction
F: stage of photo that does not require light to make glucose
B: dark reaction
F: another name for dark reaction
B: Calvin cycle

29. F: requires oxygen
B: aerobic
F: does not require oxygen
B: anaerobic
F: converts chemical energy (glucose) into usable energy (ATP) in the mitochondria
B: cellular respiration
F: ATP stands for ?
B: adenosine triphosphate
F: 3 stages of cellular respiration
B: glycolysis, Krebs cycle (citric acid cycle), electron transport chain
F: stage of cell respiration that is anaerobic
B: glycolysis & fermentation

30. F: stage of cell resp that does not occur in the mitochondria
F: stage of cell resp that does not occur in the mitochondria. Occurs in the cytoplasm
B: glycolysis
F: stages of cell resp that produces 2 ATPs
B: glycolysis and Krebs cycle (citric acid cycle)
F: stages of cell resp that is aerobic
B: Krebs cycle (citric acid cycle), and electron transport chain
F: stages of cell resp that occurs in the mitochondria
F: stage of cell resp that produces 34 ATPs
B: electron transport chain
F: folded membrane of mitochondria
B: cristae

31. F: chemical equation for cellular respiration
B: C6H12O6 + 6O2  6CO2 + 6H2O + 38 ATP
F: reactants for cell respiration
B: 1 glucose and 6 oxygens
F: products for cell respiration
B: 6 carbon dioxides, 6 waters, and 38 ATPs
F: How is energy is released from ATP?
B: when a phosphate breaks away forming ADP. When phosphate breaks away, a chemical bond is broken releasing energy.
F: our ATP must be recycled. Cell respiration adds ___ back to ADP forming ATP
B: phosphate
F: 2 types of fermentation
B: alcoholic & lactic acid

32. F: produces ethyl alcohol
B: alcoholic fermentation
F: produces lactic acid in mammals during rapid exercise; makes muscles burn
B: lactic acid fermentation