1. A. chloroplast B. photosynthesis C. cellular respiration D. glucose E
A. chloroplast B. photosynthesis C. cellular respiration D. glucose E. fermentation F. chemical energy G. mitochondria ____ 1. To stay alive, a cell must be able to release the ____________ that is stored in a molecule's bonds. ____ 2. ____________ is the process by which plants produce glucose and oxygen. ____ 3. A major energy source for most cells is a sugar molecule called ____________. ____ 4. Cells use oxygen to release the energy in glucose during ____________. ____ 5. Cellular respiration takes place in a cell's ____________. ____ 6. If a muscle cell does not have enough oxygen, it can still release energy through the process of ____________.

2. 1. F. chemical energy 2. B. photosynthesis 3. D. glucose 4. C
1. F. chemical energy 2. B. photosynthesis 3. D. glucose 4. C. cellular respiration 5. G. mitochondria 6. E. fermentation
A. chloroplast
B. photosynthesis
C. cellular respiration
D. glucose
E. fermentation
F. chemical energy
G. mitochondria
____ 1. To stay alive, a cell must be able to release the ____________ that is stored in a molecule's bonds.
____ 2. ____________ is the process by which plants produce glucose and oxygen.
____ 3. A major energy source for most cells is a sugar molecule called ____________.
____ 4. Cells use oxygen to release the energy in glucose during ____________.
____ 5. Cellular respiration takes place in a cell's ____________.
____ 6. If a muscle cell does not have enough oxygen, it can still release energy through the process of
____________.
1. F. chemical energy
2. B. photosynthesis
3. D. glucose
4. C. cellular respiration
5. G. mitochondria
6. E. fermentation

3. Time
CO2 (ppm)
12:00am
900
1:00 am
912
2:00 am
930
3:00 am
948
4:00 am
955

5. Chapter 2: How Cells Function
2.1: Chemical reactions take place inside cells
2.2: Cells capture and release energy
2.3: Materials move across the cell’s membranes
Have already learned:
-the cell is the basic unit of all living things
-Plant cells and animal cells have -similarities and differences
Will learn:
-why cells need energy
-How energy is captured and stored
-How plants and animals get energy

6. All cells need energy
Animal cells, plant cells, bacteria cells, unicellular organisms: ALL need energy
Animals get it from food
Plants get it from the sun
Type of energy = chemical energy!
Cells must release the chemical energy stored in bonds (between atoms) in order to stay alive
Cells release chemical energy from glucose (sugar molecule)

7. All cells need energy Muscle cells  Energy from? For plants:
release chemical energy from glucose to move legs 
More running, more glucose needed
Energy from?
food!
For plants:
Sunlight + water + CO2  glucose + O2

8. Some cells capture light energy
Source of ALL energy?
Ultimately…the SUN!
Photosynthesis – process that plants cells use:
Energy from sunlight into chemical energy
Takes place in plant cells that have chloroplasts
Chloroplasts contain chlorophyll
Chlorophyll absorbs light
Starting materials:
carbon dioxide (air) + water (soil)
The process:
Materials enter chloroplasts
+ energy (sunlight)
The products:
 Glucose and Oxygen!
Some glucose is linked together
to build large carbohydrates:
stored as starch

9. All cells release energy
Glucose and other sugars are “cell food”
Glucose is stored as glycogen or starch
Must be broken down to use as energy
Break the bonds of sugar – release energy!
Two ways:
Respiration
Requires oxygen
Release more usable energy than fermentation
Fermentation
Does not require oxygen

10. Cellular Respiration
Think: reverse of photosynthesis…occurs in mitochondria (chloroplasts)
Starting materials: oxygen and sugar
USE oxygen to RELEASE energy stored in sugars, such as glucose
Gain oxygen and sugars
The process:
Glucose in cytoplasm is broken down into smaller molecules, releasing some energy
Molecules move to mitochondria and oxygen enters cell (and moves to mitochondria)
The smaller molecules are further broken down
Hydrogen released (combines with oxygen to make water)
The products
Energy, carbon dioxide, water (starting products of …)
Some of this energy is transferred to other molecules, so is released as heat

12. Fermentation Cells releasing energy withOUT oxygen
When cells first break glucose into smaller molecules, a small amount of energy is released
With oxygen…cellular respiration would continue in the mitochondria
Without oxygen…fermentation continues in the cytoplasm
Two types: Alcoholic and Lactic Acid Fermentation
Both start with small molecules made from sugars
Next reactions occur producing either alcohol and carbon dioxide OR lactic acid
In both, a small amount of energy is then released

13. Fermentation Examples:
Bread: mix flour, milk, and sugar, with a microorganism yeast
Without oxygen, yeast converts the sugar into alcohol and carbon dioxide (CO2) – bubbles of CO2 gas form in the dough causing it to rise…alcohol evaporates, the yeast is killed, and CO2 makes the bread spongy
Yogurt, cheese, sourdough bread
Lactic acid bacteria convert the sugars found in milk
Sourdough bread: acidity changes  sour flavor
Yogurt and cheese: milk partially solidifies: creamy texture of yogurt…if fermentation continues  cheese

14. Energy and exercise
Some cells (and organisms) can release energy using either cellular respiration or fermentation
At rest, muscle cells store both energy and oxygen
During exercise all the energy and oxygen may be used up
Fermentation is then used to break down the sugars
Less energy than with cellular respiration
Waste product: lactic acid = burns!
Breath hard to replace used oxygen
Muscles stop hurting and build back up oxygen and energy levels

17. http://www. cambridgestudents. org
Grow a plant