1. Do Now 101
Plant and animal cells are different. Which organelle belongs to a plant cell, animal cell or both (mitochondria, chloroplast, cell wall, cell membrane).
What is the function of a:
Chloroplast –
Mitochondria –

2. 2 Important Chemical Reactions
Photosynthesis & Cellular Respiration

3. How do organisms obtain nutrients?
There are 2 ways:
Heterotrophs
Unable to synthesize own food.
Ingests food (nutrients) produced by, or available in, other organisms.
Autotrophs
Autotrophs make their own food. Also called producers
Plants do not need to ingest food. Glucose (nutrient) synthesized during photosynthesis

4. Why do living things need nutrition?
For energy to carry out
What do you call the sum total of all the chemical reactions (life functions) in an organism?
Life Functions
Metabolism

5. What are some types of autotrophs?
Mostly green plants and some single-celled organisms
Trees, grass, bushes, photosynthetic bacteria, algae

6. Photosynthesis

7. How do autotrophs make food?
Photosynthesis Photo I Synthesis Light I Creates
Purpose of Photosynthesis:
… Is to create or synthesize GLUCOSE for the plant. The plant then uses the glucose to make ENERGY.
Some animals eat plants so they can steal the glucose made in order for them to make energy!

8. Put into words, this equation tells us….
In the presence of light, plants transform CO2 and H2O into Glucose (stored chemical food energy) and releases O2 as a product.

9. Photosynthesis Equations
Carbon dioxide + water + light glucose+ oxygen
C02 + H2O + Light C6H12O6 + O2
Inorganic molecules Organic molecule + O2
Sun’s Energy Stored chemical energy (bonds)
How many types of enzymes will help catalyze the photosynthesis reaction?
Could Photosynthesis occur without sunlight?

10. Hmmm… What is the ultimate source of energy?
If photosynthesis did not take place, would we have oxygen to breath?

11. Where does photosynthesis take place?
In chloroplasts found inside the cells of leaves
Does photosynthesis take place in leaf, stems or a tree trunk?

12. How is light energy captured and used?
Plant cells that are green contain chloroplasts.
Chloroplasts contain chlorophyll….
What is chlorophyll?
Why are plants/leaves green?
What colors are absorbed best?
A pigment (type of protein) that reflects green light and absorbs other colors.
This is how light energy is captured!
Green light is reflected by chlorophyll.
Blues / Violet & Red / Maroon

13. Does the color of light affect photosynthesis?
Conclusion:
The color of light affects the rate of photosynthesis!
The Effect of the Color of Light on Plant Height
Fri
Sat
Sun
Mon
Tues
Wed
Thurs
Green -
4 mm
9 mm
17 mm
20 mm
Blue
6 mm
43 mm
50 mm
67 mm
67 mm**
Red
2 mm
59 mm
64 mm
84 mm
87 mm
Yellow
Clear
37 mm
49 mm
70 mm
75 mm
No light filter
54 mm
66 mm

14. What is going on here?
The “thing” in the beaker is a green elodea plant. What are those little bubbles in the test tube? Explain
Bubbles of oxygen produced by Photosynthesis

15. Hmmm… How can we measure the rate of photosynthesis?
Measure the amount of product produced!
How?
Measure the amount of Oxygen produced (#of bubbles)
Measure the amount of plant (size, weight)
If photosynthesis did not happen, would the plant produce sugar? Therefore, would the plant grow in size?

16. What could speed-up or slow-down the rate of photosynthesis?
6C02 + 6H2O + Light C6H12O6 + 6O2

17. Conclusions:
Color of light : Light intensity: Amount of CO2:

18. Predict what would happen if photosynthesis did not take place
Predict what would happen if photosynthesis did not take place? (give two examples).
How could you improve the rate of photosynthesis? (Give at least 2 ways)
How could you slow down or even stop photosynthesis? (Give at least 2 ways)

19. As the depth of the ocean increases, the amount of light that penetrates to that depth decreases. At about 200 meters, little, if any, light is present. The graph below illustrates the population size of four different species at different water depths.
Which species most likely performs photosynthesis?
a. 
b. 
c. 
d. 
Why?

20. How do plants get materials needed for photosynthesis?
Roots -
Absorb water from the ground.
Where does the water go once it is absorbed?
To the Leaves !
Site of photosynthesis
Where CO2 & Sunlight are absorbed (reactants)
Where H2O and O2 leave the plant (waste products)

21. How does water get up to the leaves?
Transpiration pull
Water evaporates through tiny holes in leaves called stomata
Water is drawn up from the roots and stems to replace the lost water.
**Remember, water is cohesive… water molecules love to stick together. When one water molecule evaporates, all the water in the stem is pulled up!

22. Parts of leaf Guard cells & stomata Cuticle
Spongy & Palisade Mesophyll

23. Guard Cells & Stomata
Stomata – tiny opening on bottom-side of leaf. Where water evaporates and where CO2 and O2 enter and leave the cell. (H2O leaves through stoma) Guard cells – two cells surrounding the stomata (opening). These special cells open and close the stomata.

24. How do to the guard cells open and close?
When plant have lots of water, the cells become expanded and “bow-out.” This opens the stomata. When water is low, the cells deflate, and close.
***How do guard cells help maintain homeostasis?

25. Palisade and Spongy Mesophyll
Palisade mesophyll
Top of leaf
Right beneath epidermis
Absorbs most of the light
Where most photosynthesis
happens in the leaf
Spongy mesophyll
Beneath the palisade mesophyll (bottom of leaf)
Loose tissue, with many air spaces
Lots of CO2 and O2 found here
Where gas exchange happens

26. Time out…

27. Answer Me  How does CO2 and O2 enter and leave the cell?
How does water enter and leave the cell?
How is sunlight captured in leaves?
What process takes place in leaves? And what’s the purpose?
How do guard cells help maintain homeostasis?

28. Parts of leaf Cuticle Guard cells & stomata
Spongy & Palisade Mesophyll
Label your leaf! Page 6 in packet.

29. Another Look

30. Review

31. Review

32. Review

34. Do Now Do plant cells have mitochondria?
Do plant cells use oxygen and glucose? Why?
So… do plants give off some carbon dioxide? (CO2)

35. Do Now What is needed (reactants) for photosynthesis?
What are the products of photosynthesis?
Why does photosynthesis take place? Why is it important?

36. Do Now (5) Finish the formula:
______________ + ________ + light __________+ __________