1. Photosynthesis and Plants

2. Heterotrophs and Autotrophs  Organisms that obtain food by consuming other living things are known as heterotrophs.

3. Heterotrophs and Autotrophs  Some heterotrophs get their food by eating plants.  Other heterotrophs, such as the cheetah, obtain food from plants indirectly by feeding on plant-eating animals.  Still other heterotrophs, such as mushrooms, obtain food by decomposing other organisms.

4. Heterotrophs and Autotrophs  Organisms that make their own energy are known as autotrophs.

5. Heterotrophs and Autotrophs  Plants, algae, and some bacteria are able to use light energy from the sun to produce food.  The process by which autotrophs use the energy of sunlight to produce high-energy carbohydrates that can be used for food is known as photosynthesis.

6. What is the difference between a heterotroph and an autotroph? A) Heterotrophs make their own food and autotrophs have to eat other organisms to obtain energy B) Autotrophs make their own food and heterotrophs have to eat other organisms to obtain energy C) There is no difference

7. Short Answer #4 Explain how the ultimate source of energy for heterotrophs is the sun even though they cannot make their own food

8. What Plants Need?  All plants have the same basic needs: sunlight, a way to exchange gases with the surrounding air, water, and minerals.

9. Sunlight  Plants use the energy from sunlight to carry out photosynthesis.  Leaves are typically broad and flat and are arranged on the stem so as to maximize light absorption.

10. Gas Exchange  Plants require oxygen to support cellular respiration, as well as carbon dioxide to carry out photosynthesis.  Plants must exchange these gases with the atmosphere and the soil without losing excessive amounts of water through evaporation.

11. Water and Minerals  Land plants have evolved structures that limit water loss and speed the uptake of water from the ground.  Minerals are nutrients in the soil that are needed for plant growth.

12. Water and Minerals  Many plants have specialized tissues that carry water and nutrients upward from the soil and distribute the products of photosynthesis throughout the plant body.

13. What do plants need to survive? A) Water, sugar, nutrients and minerals B) Water, sugar, sunlight and minerals C) Water, sunlight, gas exchange and minerals D) Water, gas exchange, sugar and minerals

14. What is a selective advantage of having flat, broad leaves? A) Maximize water loss B) Maximize gas exchange C) Maximize sun absorption D) Both B & C

15. Chemical Energy and ATP  ATP can easily release and store energy by breaking and re-forming the bonds between its phosphate groups.  This characteristic of ATP makes it exceptionally useful as a basic energy source for all cells.

16. Chemical Energy and ATP  One of the most important compounds that cells use to store and release energy is adenosine triphosphate (ATP).  ATP is a nucleic acid (macromolecule)  ATP consists of adenine, a 5-carbon sugar called ribose, and three phosphate groups.

17. Releasing Energy  Cells can release the energy stored in ATP by breaking the bonds between the second and third phosphate groups.  Because a cell can add or subtract these phosphate groups, it has an efficient way of storing and releasing energy as needed.

18. How do organisms get energy from an ATP molecule? A)Breaking bonds between the second and third phosphate group B) Building a bond between the second and third phosphate group C) Building a bond between the first and second phosphate group D) Breaking bonds between the first and second phosphate group

19. Photosynthesis and Pigments  Plants gather the sun’s energy with light- absorbing molecules called pigments.  The plants’ principal pigment is chlorophyll.

20. Pigments  The two types of chlorophyll found in plants, chlorophyll a and chlorophyll b, absorb light very well in the blue-violet and red regions of the visible spectrum, but not in the green region, as shown in the graph.  Leaves reflect green light, which is why plants look green.

21. Pigments  Plants also contain red and orange pigments such as carotene that absorb light in other regions of the spectrum.  Most of the time, the green color of the chlorophyll overwhelms the other pigments, but as temperatures drop and chlorophyll molecules break down, the red and orange pigments may be seen.

22. Chloroplasts  Photosynthesis takes place inside organelles called chloroplasts.

23. Energy Collection  Because light is a form of energy, any compound that absorbs light absorbs energy. Chlorophyll absorbs visible light especially well.  When chlorophyll absorbs light, a large fraction of the light energy is transferred to electrons. These high-energy electrons make photosynthesis work.

24. High-Energy Electrons  The high-energy electrons produced by chlorophyll are highly reactive and require a special “carrier.”  Plants use electron carriers to transport high-energy electrons from chlorophyll to other molecules.

25. High-Energy Electrons  NADP + (nicotinamide adenine dinucleotide phosphate) is a carrier molecule.  NADP + accepts and holds two high-energy electrons, along with a hydrogen ion (H + ). In this way, it is converted into NADPH.  The NADPH can then carry the high-energy electrons to chemical reactions elsewhere in the cell.

26. Overview of Photosynthesis  Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into high-energy sugars and oxygen. 6 CO 2 + 6 H 2 O  C 6 H 12 O 6 + 6 O 2 Carbon Dioxide Water Light Glucose Oxygen

27. Light-Dependent Reactions  Photosynthesis involves two sets of reactions.  The first set of reactions is known as the light- dependent reactions.  These reactions take place within the thylakoid membranes of the chloroplast.

28. Light-Independent Reactions  During light-independent reactions, ATP and NADPH molecules produced in the light-dependent reactions are used to produce high-energy sugars from carbon dioxide.  The light-independent reactions take place outside the thylakoids, in the stroma.

29. What is the energy carrier molecule used in photosynthesis? A) Chloroplast B) Pigment C) Chorophyll D)NADP +

30. Photosynthesis is to Chloroplast as Cellular Respiration is to: A) Chlorophyll B) Mitochondria C) Thylakoid D) Stroma

31. Factors that Affect Photosynthesis  Among the most important factors that affect photosynthesis are  temperature  light intensity  availability of water.

32. Temperature  The reactions of photosynthesis are made possible by enzymes that function best between 0°C and 35°C.  Temperatures above or below this range may affect those enzymes, slowing down the rate of photosynthesis or stopping it entirely.

33. Light Intensity  High light intensity increases the rate of photosynthesis.  After the light intensity reaches a certain level, however, the plant reaches its maximum rate of photosynthesis, as is seen in the graph.

34. Light Color  Color of light affects rate of photosynthesis  Chlorophyll reflects green light.

35. Availability of Water  Because water is one of the raw materials in photosynthesis, a shortage of water can slow or even stop photosynthesis.

36. Comparing Photosynthesis and Cellular Respiration  Photosynthesis removes carbon dioxide from the atmosphere, and cellular respiration puts it back.  Photosynthesis releases oxygen into the atmosphere, and cellular respiration uses that oxygen to release energy from food.

37. Comparing Photosynthesis and Cellular Respiration  The energy flows in opposite directions. Photosynthesis “deposits” energy, and cellular respiration “withdraws” energy.  The reactants of cellular respiration are the products of photosynthesis and vice versa.

38. PhotosynthesisRespiration Equation6CO 2 + 6H 2 O → C 6 H 12 O 6 + 6O 2 C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O ReactantsCarbon Dioxide Water Glucose Oxygen ProductsGlucose Oxygen Carbon Dioxide Water Organelle in which process is carried out ChloroplastMitochondria Types of organisms which carry out the process Plants Algae and some Protists Some Bacteria All Living Things

39. If you continue to increase the intensity of light that a plant receives, what happens? A).The rate of photosynthesis increases indefinitely with light intensity. B).The rate of photosynthesis decreases indefinitely with light intensity. C).The rate of photosynthesis increases and then levels off. D).The rate of photosynthesis does not change.

40. 1) Autotroph makes their own food; heterotrophs rely on other organisms for food (1pt) 2) Plants are green because their pigments reflect green light. (1 pt) 3) Presence of CO2(1pt)

41. Which of the following is one of the ways that cellular respiration and photosynthesis are opposite processes? a).Photosynthesis releases energy, and cellular respiration stores energy. b).Photosynthesis removes carbon dioxide from the atmosphere, and cellular respiration puts it back. c). Photosynthesis removes oxygen from the atmosphere, and cellular respiration puts it back. d).Photosynthesis consumes glucose, and cellular respiration produces glucose.