Chapter 7: Photosynthesis

Question 1

What is the general equation for photosynthesis?

7.1

Answer 1

6 CO2 + 12 H20 + Light energy –> C6H12O2 + 6 H2O

Question 2

In the process of photosynthesis, light energy is captures which is used to synthesize _______

7.1

Answer 2

Carbohydrates

Question 3

In photosythesis, what molecule is Oxidized and what molecule is Reduced

7.1

Answer 3

H20 (water) = Oxidized
CO2 (carbon dioxide) = Reduced

Question 4

What are the 2 categories that classify organisms and explain the differences?

7.1

Answer 4

Autotrophs; make organic molecules from inorganic sources
Heterotrophs; must consume food/ aquire organic molecules from environment

Question 5

Name the organelle that photosythesis takes place in

7.1

Answer 5

The Chloroplast

Question 6

What part of the plant does photosythesis occur?
a. Stem
b. Leaves
c. Roots
d. Bud

7.1

Answer 6

c. Leaves

specifically mesophyll cells

Question 7

Name the 2 stages of photosynthesis

7.1

Answer 7

Light Reactions and The Calvin Cycle

Question 8

What are the products of Light Reaction?

(hint: there are 3 products)

7.1

Answer 8

ATP, NADPH, and O2

Question 9

What are the products of The Calvin Cycle?

7.1

Answer 9

G3P, NADP+, and ADP+Phosphate

Question 10

Light is a type of ________ radiation; it consist of energy in the form of electric and magnetic waves

7.2

Answer 10

Electromagnetic

Question 11

Select ALL that are TRUE

When light encounters a molecule, it can:
-Pass through the molecule
-Bounce off the molecule
-Change its path toward a different direction
-Become absorbed by the molecule
-Decrease the molecules temperature

7.2

Answer 11

-Pass through the molecule
-Bounce off the molecule
-Change its path toward a different direction
-Become absorbed by the molecule

Question 12

______ are the molecues that can absorb light

7.2

Answer 12

Pigments

Question 13

Molecules have 2 states, one involves the molecule in a “normal” state and the other, when the electron of the molecule absorbs energy.
Name the 2 states

7.2

Answer 13

Ground State; the “normal state”
Excited State; when an electron absorbs energy

Question 14

Name the 3 ways electrons release energy

7.2

Answer 14

Heat, Light, and Transferred/Captured

Note: Excited electron in pigments can transfer energy only

Question 15

What are the two types of Chlorophyll pigments?

7.2

Answer 15

Chlorophyll a AND Chlorophyll b

Question 16

The ____ anchors the pigment to the protein within the thylakoid membrane

7.2

Answer 16

Hydrocarbon tail

Question 17

Within the thylakoid membrane, 2 distinct pigment molecules are present.

What are these 2 pigment molecules?

7.2

Answer 17

Photosystem I and II

Question 18

Name the pigment in Photosystem II

7.2

Answer 18

P680

Question 19

Name the pigment in Photosystem I

7.2

Answer 19

P700

Question 20

The ____ ____ ____ contains the combined action of PS II and PS I

7.2

Answer 20

Linear Electron Flow

Question 21

The ____ ____ ____ uses PSI ONLY

7.2

Answer 21

Cyclic Electron Flow

Question 22

Name the products of Linear electron flow

7.2

Answer 22

ATP and NADPH

Question 23

Name the products of the Cyclic electron flow

7.2

Answer 23

ATP ONLYYYYYY

Question 24

True or False

The linear electron flow produces enough ATP to initate the Calvin Cycle

7.2

Answer 24

False, This lack of ATP production is resovled by the cyclic electron cycle

Question 25

# True or False The Calvin Cycle uses more NADPH than ATP ## Footnote 7.2

Answer 25

False, it uses more ATP than NADPH

Question 26

# True or False The Cyclic electron flow activates when levels of NADP+ low and NADPH is high ## Footnote 7.2

Answer 26

True, it also activates when ATP levels are low

Question 26

How is the ATP Synthase activated? ## Footnote 7.2

Answer 26

When H+ creates an **electrochemical gradient** in the thylakoid lumen, causing the H+ to travel and reach the ATP Synthase | NOTE: this process happens in both Linear and Cyclic Electron Flow

Question 27

PS I and II have **2** main componets. One componet is composed of many pigment molecules **anchored to the transmembrane protein** One is the site where the **redox** reaction takes place it and contains **P680** ## Footnote 7.3

Answer 27

Light-Harvesting Complex: The componet that contains many pigmets and is anchored to the transmembrane Reaction Center: The site where redox reaction takes place, contain the P680

Question 28

Which protein complex/s can oxidize water, resulting in the release of O2 ## Footnote 7.3

Answer 28

PS II ONLY

Question 29

Describe the Z Scheme model ## Footnote 7.3

Answer 29

Z Scheme refers to the zigzag shape of the energy curve. Z Scheme proposed that photosynthesis involves 2 events of light absorption

Question 30

What is the product of the Calvin Cycle ## Footnote 7.4

Answer 30

G3P or Glyceraldehyde-3-phosphate

Question 31

Name the **3** phases of the Calvin Cycle and describe their function ## Footnote 7.4

Answer 31

**Carbon Fixation** - CO2 is incorporated into RuBP, a 5-carbon sugar; the enzyme **Rubisco** catalyzes this reation and the 6-carbon intermediate splits into two 3-carbon molecules **Reduction and carbohydate production** - ATP is used as a source of energy and NADPH is used a a source of high-energy electrons; **G3P** is produced **Regeneration of RuBP** - Most of the G3P is used to regenerate RuBP, allowing the cycle to continue

Question 32

What environment conditions alters the operation of the Calvin Cycle | there are 3 different ones ## Footnote 7.5

Answer 32

- Temperature - Water Avaliability - Light Intesity

Question 32

# True or False C3 plants are more combatable in warmer environments ## Footnote 7.5

Answer 32

False

Question 33

When does photorespiration occur? ## Footnote 7.5

Answer 33

When rubisco adds O2; as intermediates are processed, a molecule of CO2 is released

Question 34

C4 and CAM plants make ____ in the first step of carbon fixation ## Footnote 7.5

Answer 34

oxaloacetate

Question 34

In C4 Plants, the leaves have a two-cell layer organization. Name these two layers ## Footnote 7.5

Answer 34

Messophyll cells Bundle-sheath cells

Question 34

____ Plants open their stomata at night ## Footnote 7.5

Answer 34

C4 or CAM Plants

Question 35

# True or False CAM and C4 plants use more energy to fix CO2 than C3 plants ## Footnote 7.5

Answer 35

True; C3 plants use less energy

Question 36

# True or False CAM and C4 plants are more habitable in warmer and drier environments ## Footnote 7.5

Answer 36

True