Unit V – Cell Energy
The Story of
Mitochondria & Chloroplasts
How Do Cells Transform
Energy?
• Background Info:
• 1) cells need energy to do work
• 2) the food cells eat to make ATP is called
glucose
• 3) the molecule cells use to store energy is
called ATP
• 4) heterotrophs must eat food to get glucose,
…autotrophs can make their own glucose
• Purpose:
Fermentation
– Make ATP when there is no oxygen present
• Who Does It:
– Bacteria
– Yeast cells
– Muscle cells
• Site:
– Cytoplasm
Fermentation
• Two Types:
1) Alcoholic Fermentation
Glucose  CO2 + alcohol + ATP
used to make breads & beer
2) Lactic Acid Fermentation
Glucose  lactic acid + ATP
overexerted muscles; dairy products
Endosymbiont Theory
• Mitochondria & chloroplasts are thought to
have come from ancient prokaryotic cells
Evidence: Both mitochondria and chloroplasts…
• have their own DNA
• have their own ribosomes
• have membranes similar to bacteria
• divide like bacteria (binary fission)
Cellular Respiration
Cellular Respiration
• Purpose:
– Make energy (ATP) for cells
• Site:
– Mitochondria
• Equation:
– C6H12O6 + O2  CO2 + H2O + ATP (energy
– glucose + oxygen  carbon dioxide + water + ATP
Cellular Respiration
•
Who Does It:
– All eukaryotes
• Description:
1) Glycolysis: glucose broken into 2 pieces…
makes 2 ATP’s
2) Krebs Cycle & Electron Transport Chain:
continue the complete breakdown of the glucose
molecule…makes 36 ATP’s
Photosynthesis
• Purpose:
– Make glucose for cells
• Site:
– Chloroplast
• Equation:
– carbon dioxide + water + light  glucose + oxygen
– CO2 + H2O + light (energy)  C6H12O6 + O2
Photosynthesis
• Who Does It:
– Algae, plants, blue-green bacteria
• Description
1) Light Reactions: Chlorophylls catch light & use
its energy to make ATP & NADPH (O2 as waste)
2) Calvin Cycle: ATP used to change CO2 into
glucose molecules (which are then stored as starch)
Relationship between
Cell Respiration & Photosynthesis
• Sketch (& label) the
overall plan
All actions in an organism ultimately
happen on the cellular level!
• On the cellular level, why do we need to
breathe oxygen?
• On the cellular level, why do we need to
eat food?
All actions in an organism ultimately
happen on the cellular level!
• On the cellular level, why do plants need
light?
• On the cellular level, why do plants need
carbon dioxide?
The End
Fake Quiz #1
• 1. Why do cells need energy at all?
• 2. Which food molecule do they “burn”?
• 3. If that food molecule (from #2 above) is so
full of energy, why is ATP made?
• 4. Where in the ATP molecule is all of that
energy located?
• 5. Who “invented” fermentation?
• 6. What are 2 “old-fashioned” traits that
fermentation exhibits? (hint: location & O2)
Lab – Fermentation #1
I. Purpose: How does the amount of sugar
affect the amount of CO2 produced?
II. Background:
glucose  CO2 + alcohol + ATP
III. Hypothesis: As more sugar is added,
the amount of CO2 will ____.
IV. Procedure: (Copy picture on board)
Lab – Fermentation #1
V. Data
Amt of Sugar (mL) Amt of CO2 (ppm)
0
5
20
Net CO2 Produced
(ppm)
Lab – Fermentation #1
V. Data
Amt of
CO2
(ppm)
Amount of Sugar (mL)
Lab – Fermentation #1
VI. Conclusion
1. The data shows that as more sugar is
added, the CO2 levels…
2. This supports/does not support my
hypothesis.
3. This lab relates to fermentation because…
4. A source of error in this experiment is…
Lab – Fermentation #2
I. Purpose: Which sugar do yeast prefer?
II. Background: Glucose  CO2 + alcohol + ATP
III. Hypothesis: (write a statement that answers your
purpose question)
IV. Procedure: (copy diagram from board)
V. Data (copy the data table…then graph the data)
Lab – Fermentation #2
VI. Conclusion
1. The data shows that yeast cells prefer…
We could tell that this was true because…
2. This does/does not support our hypothesis.
3. A source of error in this experiment is…
Quiz #1
1. Which of the following would NOT require
cells to use ATP?
A. Osmosis
B. Growing
C. Reproducing
D. Moving
Quiz #1
2. On the cellular level, why is it necessary for
us to eat food?
A. Our stomachs get hungry
B. Our intestines empty
C. Our cells need glucose
D. Our cells need oxygen
Quiz #1
3. Which of these is FALSE?
A. Breaking down glucose gives off energy
B. Breaking down ATP gives off energy
C. Cells use ATP for cell work
D. 1 ATP has more energy than 1 glucose
Quiz #1
4. The energy in ATP is A. Stored between its phosphate groups
B. Stored in the vacuoles
C. Not widely used by cells
D. Not very useful
Quiz #1
5. Which cells can form ATP by breaking down
glucose?
A. Prokaryotes only
B. Animals only
C. Plants only
D. All cells
Quiz #1
6. Fermentation A. Requires oxygen
B. Occurs in the cytoplasm
C. Is only done by yeast cells
D. Does not make ATP
Quiz #1
7. The formula for one type of fermentation is
Glucose  CO2 + alcohol + ATP
If yeast cells are given more sugar, then they will -
A.
B.
C.
D.
Make less CO2
Make more ATP
Be poisoned by alcohol
Be poisoned by oxygen
Quiz #1
• 1. Why do cells need energy at all?
• 2. Which food molecule do they “burn”?
• 3. If that food molecule (from #2 above) is so
full of energy, why is ATP made?
• 4. Where in the ATP molecule is all of that
energy located?
• 5. Who “invented” fermentation?
• 6. What are 2 “old-fashioned” traits that
fermentation exhibits? (hint: location & O2)
Fake Quiz #2
• 1. Which cells invented fermentation?
• 2. What is the purpose of fermentation?
• 3. Which food molecule is broken down in
fermentation?
• 4. How many ATP are made in fermentation?
• 5. Where in the cell does fermentation occur?
• 6. Is fermentation aerobic or anaerobic?
…what does that mean?
Fake Quiz #2
•
•
•
•
•
•
•
•
7. How does PS change life on earth?
8. Which type of cells can do PS?
9. Where in the cell does PS happen?
10. What is the purpose of Part 1 of PS?
11. Does Part 1 of PS need light?
12. What is the purpose of Part 2 of PS?
13. Does Part 2 of PS need light?
14. What is the carbon source for PS?
Lab – Photosynthesis Rate
I. Purpose: How does the amount of light
affect the rate of photosynthesis?
II. Background:
CO2 + H2O + light (energy)  C6H12O6 + O2
III. Hypothesis: The more light plants
receive, the ____ photosynthesis will occur.
IV. Procedure: (draw pic)
Lab – Photosynthesis Rate
V. Data
Amt Light
(%)
Start [DO]
(mg/L)
Amt of Light (%)
0%
25%
50%
75%
100%
End [DO]
(mg/L)
Net [DO]
produced
(mg/L)
Avg Dissolved Oxygen
Produced (mg/L)
Lab – Photosynthesis Rate
VI. Conclusion
1. The data shows that as plants get more
light, the rate of photosynthesis…
We could tell that this was true because…
2. This does/does not support my hypothesis.
3. A source of error in this experiment is…