1. Biology Unit Three - Energy
Mrs. Pearson’s First Semester Biology
*For those watching by recording, watch for questions on the slides throughout
the presentation. me the answers to the questions within two days of the
lesson being presented in order to receive credit for watching the recording.

2. Biology Olympics Break it Down! Today’s word is “chemosynthesis”
Chemo means…
Synthesis means…

3. Biology Olympics
Chemosynthesis is the use of chemicals by an organism to generate usable energy

4. Biology
USA

5. KEY CONCEPT All cells need chemical energy.

6. Lesson Objectives
Describe the processes and products of photosynthesis.

7. Pearson’s Perfectly Pleasant Prefixes and Parts
Tri –
Di –
Chemo -
Photo –
Synthesis
Produce
Consume

8. Why do cells need energy
Why do cells need energy? What kinds of things do cells need to do that require energy?
Organisms get their energy in different ways – why is this a good thing? What would happen if all organisms got their energy in the same way?
If all organisms got their energy in the same way, energy would move in a linear fashion eventually being completely changed into an unusable form. Energy cycles through systems being transferred from one area to another. What else do we see in the environment that cycles?
What should humans be careful to make sure “cycles” in our interactions with nature?

9. The chemical energy used for most cell processes is carried by ATP.
Molecules in food store chemical energy in their bonds.
Starch molecule
Glucose molecule
**Those watching by recording, include in your where food molecules store chemical energy

10. Energy is released when a phosphate group is removed.
ATP transfers energy from the breakdown of food molecules to cell functions.
Energy is released when a phosphate group is removed.
ADP is changed into ATP when a phosphate group is added.
phosphate removed

11. Organisms break down carbon-based molecules to produce ATP.
Carbohydrates are the molecules most commonly broken down to make ATP.
not stored in large amounts
up to 36 ATP from one glucose molecule
triphosphate
adenosine
diphosphate
tri=3
di=2

12. Fats store the most energy.
80 percent of the energy in your body
about 146 ATP from a triglyceride
Proteins are least likely to be broken down to make ATP.
amino acids not usually needed for energy
about the same amount of energy as a carbohydrate

13. A fat by any other name…
What two other names did you see for “fats” on the previous slide?
Triglycerides
Lipids

14. A few types of organisms do not need sunlight and photosynthesis as a source of energy.
Some organisms live in places that never get sunlight. Like where?
In chemosynthesis, chemical energy is used to build carbon-based molecules.
similar to photosynthesis
uses chemical energy instead of light energy
Where could this chemical energy be coming from?

15. KEY CONCEPT The overall process of photosynthesis produces sugars that store chemical energy.

16. Photosynthetic organisms are producers.
Producers make their own source of chemical energy.
Name three producers you would find in a grocery store.
Plants use photosynthesis and are producers.
Photosynthesis captures energy from sunlight to make sugars.
**Those watching by recording, include in your the definition of a producer.

17. Chlorophyll is a molecule that absorbs light energy.
chloroplast
leaf cell
leaf
In plants, chlorophyll is found in organelles called chloroplasts.
Why don’t we find chlorophyll in animal cells?

18. The light-dependent reactions capture energy from sunlight.
take place in thylakoids
water and sunlight are needed
chlorophyll in the thylakoids absorbs energy
energy is transferred along thylakoid membrane then to light-independent reactions
oxygen is released
Water, sunlight and oxygen are found in this part of the process – what are we missing?
Carbon dioxide

19. The light-independent reactions make sugars.
take place in stroma
needs carbon dioxide from atmosphere
use energy to build a sugar in a cycle of chemical reactions

20. The equation for the overall process is:
6CO2 + 6H2O  C6H12O6 + 6O2
C6H12O6
granum (stack of thylakoids)
thylakoid
sunlight
1 six-carbon sugar
6H2O
6CO2
6O2
chloroplast 1 2 4 3
energy
stroma (fluid outside the thylakoids)
**Those watching by recording, include in your the equation for photosynthesis.

21. Questions?