Calvin cycle reactants

Study Guide Chapter 10-Answers!

10.1 Photosythesis_______________________________________________________

1A. Write the overall reaction (major reactants and major products) for photosysthesis:

sunlight + water + CO2 ( O2 and glucose

B. Where is each reactant used (light reactions or Calvin cycle?)

Sunlight= light reactions

Water= light reactions (when it is “split” the electrons in the bonds of water are used to replace the electrons lost from the P680 reaction center)

CO2= Calvin cycle

C. Where is each product produced (light reactions or Calvin cycle?)

O2= light reactions (when water is “split”)

Glucose= Calvin cycle

2. Compare and contrast Autotrophs and Heterotrophs.

Auto- make their own food

Hetero- rely on autotrophs for food

3. A. Where would you most likely find mesophyll cells in a tree?

Any photosynthetic part of the tree. Leaves are the main photosynthetic organs in the tree.

B. How many chloroplasts does a typical mesophyll cell hold? 30-40

C. What pigment gives a leaf its green color? chlorophyll

D. Where exactly is this pigment located? Within chloroplasts

E. How does carbon dioxide enter the leaf? Through stomata in the leaves

4. Chloroplast structure: Name all components of the chloroplast and describe their orientation relative to one another. Start at the outer membrane and end inside a thylakoid.

Outer membrane

Intermembrane space

Inner membrane

Stroma

Thylakoid membrane

Thylakoid space

5. Identify the two main stages of photosynthesis and where these stages occur respectively. Also describe how the two stages are dependent on one another.

Stage 1= Light reactions- in thylakoid membranes and thylakoid space, the main products of this stage are some the main reactants of the next stage

Stage 2= Calvin cycle- in stroma, some of the products of this stage are some of the main reactants for stage 1.

10.2 Light Rxns. Chemical Energy of Sun ( ATP and NADPH____________________

6. Green light is _____reflected______________ (reflected/absorbed) by a chloroplast, giving it its green color.

7. What wavelengths of light are most effective in driving photosynthesis?

Violet and red

Briefly describe the experiment (discussed in the chapter and powerpoint for this chapter) that identified these wavelengths of light.

The plants produced high levels of oxygen (one of the major products of photosynthesis) when exposed to violet and red light and produced little to no oxygen when exposed to other wavelengths of light. This makes sense. Think about the photosystem reaction centers in the thylakoid membranes of the chloroplast. P680 and P700, the letter “P” represents “photosystem” and the numbers refer to the wavelengths of light the photosystems absorb. Wavelengths 680 and 700 are both in the red range!

8. Describe what happens when chlorophyll absorbs light?

Electrons in chlorophyll absorb energy and are “jumped” to higher energy level.

9. Photosystems: What are they and where are they located?

Light harvesting complexes in thylakoid membranes of chloroplasts.

Identify the components of the photosystem reaction center.

Reaction center:

Light harvesting complexes

Chlorophyll Pigment molecules

Special chlorophyll a molecules

Primary electron acceptor

10. Describe the path of a photon of light starting outside the chloroplast through the photosystem reaction center to the primary electron acceptor. Light from sun ( outer membrane of chloroplast (inner membrane of chloroplast ( stroma ( light harvesting complex within thylakoid membrane (photosystem) ( chlorophyll pigment molecules within the photosystem( electrons of the special chlorophyll a molecules in the reaction center ( primary electron acceptor in the reaction center

11. In photosystem II why is it necessary to split water into Oxygen, hydrogen ions and electrons?

To replace electron “jumped” or lost from the special chlorophyll a molecules in the P680 reaction center of the photosystem. Electrons are jumped or lost to primary electron acceptor when a photon of light energizes the electrons in the special chlorophyll a molecules.

12. What is generated in photosystem II reactions? (2 products)

O2 and ATP

13, Where do the electrons that replace the electron lost from the special chlorophyll a molecules of photosystem I in the P700 reaction center come from?

PSII

14. What is generated in photosystem I reactions? (1 product)

NADPH

15. Where are the products of photosystem II and I used?

Calvin Cycle

16. Compare and contrast cell respiration in mitochondria and photosynthesis in chloroplasts in terms of…

A. Where the hydrogen ion gradient forms (where hydrogen ions are concentrated).

B. Chemiosmosis (movement of Hydrogen ions through the ATP synthase to generate ATP)

Mitochondria

A. H+ are pumped from matrix through the inner membrane to the intermembrane space by action of electron transport chain protein pumps. Hydrogen ion gradient forms in the intermembrane space.

B. Hydrogen ions move from the intermembrane space to the matrix through the ATP synthase, generating ATP in the stroma!

Chloroplast

A. H+ are pumped from the stroma through the thylakoid membrane to the thylakoid space by action of an electron transport chain protein pump.

B. Hydrogen ions move from the thylaokid space to the stroma through the ATP synthase, generating ATP in the matrix!

17. Why is it that when the lights are turned off in a laboratory, the