Chapter 8

Photosynthesis

8-1 Energy and Life

I. Autotrophs-make food using sunlight

II. Heterotrophs - obtains energy from food they consume

III. Energy is the “currency” of the cell

A. ATP1. Adenosine Triphosphate2. Chemical compound cells use to store energy3. PARTS:

a. Adenine b. 3 phosphate groups c. Ribose

(5 carbon sugar)

8-1 Continued

B. ADP1. Adenosine Diphosphate

2. Has 2 phosphate groups

3. Chemical compound that can be converted to ATP to store energy

4. HOW?

a. Bond 1 more phosphate group

5. Analogy:

Half charged battery

b. Energy is in the bond between phosphate groups

4. Analogy Fully charged battery

C. Releasing Energy

1. Break bond of second and third phosphate group and energy is released

2. ATP ADP + P + Energy

3. ATP is the preferred energy source to power the cell activities

2 Phosphate groups

ADP

D. ATP and Glucose

1. Glucose stores 90X more energy than 1 ATP molecule

2. Cells use ATP for quick energy not long term energy

3. Cells only store enough ATP for a few seconds of activity

8-2 Photosynthesis

A. Process in which chloroplast convert light energy from CO2 and H2O into O2 and high energy carbohydrates (glucose)

B. Photosynthesis Equation

light

6CO2 + 6H2O C6H12O6 + 6O2

carbon dioxide + water glucose + oxygen

IV. Photosynthesis

C. Light and Pigments

1. Chlorophylla. green pigment in chloroplast that absorbs wavelengths of light

b. 2 types: chlorophyll a and chlorophyll b 1. Absorb most wavelengths

of light except green

(why plants are green)

c. In the fall, trees reabsorb chlorophyll and the other pigments are visible

8-3 Reactions of Photosynthesis

V. Takes place inside the ChloroplastA. Thylakoids = saclike membranes that contain chlorophyll to capture light

1. granum = stacks of thylakiods

B. Stroma = fluid filled space around thylakoids

C. Two types of reactions1. Light Dependent

2. Light Independent / Calvin Cycle / Dark Reaction

Chloroplast

Singlethylakoid

Granum

Stroma

Light

PHOTOSYNTHESISPHOTOSYNTHESIS

CO2

Calvin cycle

O2Sugars

Light- dependent reactions

NADP+

ADP + P

H2Op208

VI. Electron Carriers = Energy Carriers

A. NADP+ = transport electrons (aka: Taxi)

B. H+ = high energy electrons (aka: passengers)

C. NADP+ picks up H+ and brings them elsewhere and drops them off

D. NADPH drops off H+ for electron transfer at proteins that starts chemical reactions

VII. Light Dependent ReactionA. Requires light to take place

E. Lost electrons are replaced by Hydrolysis (aka photolysis (splitting of water)

D. Light strikes thylakoid; electrons excited; go to the ETC form NADPH and ATP, respectively.

C. Uses light to split water for H; releases O2 gas and makes high energy electrons & ATP

B. Takes place in thylakoids

VIII. Calvin Cycle/Light Independent/ Dark Reactions

A. Does not need light to take place

D. Six turns of the Calvin Cycle makes 1 glucose molecule

C. Powered by NADPH and ATP and uses 6CO2 molecules to produce high energy sugar (glucose)

B. Takes place in stroma

IX. Factors Affecting Photosynthesis

A. Water shortage 1. slow/stop photosynthesis

C. Light Intensity

1. increase light = speeds up photosynthesis

2. decrease light = slows down photosynthesis

B. Temperature 1. enzymes cause photosynthesis to speed up2. too hot = slow/ stop photosynthesis.

Chapter 9

Cellular Respiration

9-1 Chemical Pathways

I. Cellular Respiration: A. Process by which mitochondria breaks down

glucose to make ATP

B. Cellular Respiration Equation:

6O2 + C6H12O6 6CO2 + 6H2O

Oxygen + Glucose Carbon Dioxide + Water

Glycolysis

Cytoplasm

Glucose

Electrons carried in NADH

Pyruvic Acid

Mitochondria

Electrons carried in NADH and FADH2

p222

2 ATP 2 ADP 4 ADP 4 ATP

2 Pyruvic acid

d. Pyruvic Acid moves into the mitochondria1) Produces 4 ATP but uses 2 ATP’s to start glycolysis

c. Breaks down glucose into 2 molecules of pyruvic acid and produces 2 net ATP molecules

b. Occurs in Cytoplasm

1. Glycolysis:a. anaerobic process = NO Oxygen is required

C. Three Stages:

2. Krebs Cycle (aka. Citric Acid Cycle)

a. Aerobic Respiration = Requires Oxygen

b. Produces 2 ATP

c. Releases CO2, NADH, and FADH2

d. NAD+ and FAD are “taxis”, take electrons to the ETC

3. Electron Transport Chain

b. Oxygen is the Final Electron Acceptor

c. Produces 32 ATP molecules

a. Aerobic Respiration = Requires Oxygen

D. ATP Produced:

1. from Glycolysis 4(2 are used to start therefore only 2 net)

2. from Krebs Cycle2

3. from ETC32

4. Total of ATP molecules or net ATP38 36

II. In the absence of Oxygen: Fermentation

A. Anaerobic Respiration: (does NOT require O2)1. Follows glycolysis= 2ATP

2. TWO TYPES:

a. Lactic Acid Fermentation

1) In animals

3) Lactic acid build up in muscles results in muscle fatigue

2) Pyruvic Acid used NADH to make 2 molecules of Lactic Acid

pyruvic acid + NADH → lactic acid + NAD+

b. Alcoholic Fermentation:

1) Used by yeast cells

pyruvic acid + NADH → alcohol + CO2 + NAD+

III. Comparing Photosynthesis and

Cellular RespirationA. Photosynthesis and cellular respiration take place in opposite directions.

Photosynthesis

Cellular Respiration

B. Photosynthesis vs. Respiration

1. Food Made 1. Food break down

2. Carbon Dioxide In 2. Carbon Dioxide Out

3. Oxygen Out 3. Oxygen In

4. Makes Glucose 4. Breaks down Glucose

5. Happens in Light 5. Day and Night

6. Only with chlorophyll 6. All living cells

7. Takes place in Chloroplast7. Takes place in mitochondria

8-1Organisms that make their own food are called

A. autotrophs.

B. heterotrophs.

C. decomposers.

D. consumers.

8-1

Most autotrophs obtain their energy from

A. chemicals in the environment.

B. sunlight.

C. carbon dioxide in the air.

D. other producers.

8-1

How is energy released from ATP?

A. A phosphate is added.

B. An adenine is added.

C. A phosphate is removed.

D. A ribose is removed.

8-1How is it possible for most cells to function with

only a small amount of ATP?

A. Cells do not require ATP for energy.

B. ATP can be quickly regenerated from ADP and P.

C. Cells use very small amounts of energy.

D. ATP stores large amounts of energy.

8-1Compared to the energy stored in a molecule of

glucose, ATP stores

A. much more energy.

B. much less energy.

C. about the same amount of energy.

D. more energy sometimes and less at others.

8-2

The raw materials required for plants to carry out photosynthesis are

A. carbon dioxide and oxygen.

B. oxygen and sugars.

C. carbon dioxide and water.

D. oxygen and water.

8-2

The principal pigment in plants is

A. chloroplast.

B. chlorophyll.

C. carotene.

D. carbohydrate.

8-2

The colors of light that are absorbed by chlorophylls are

A. green and yellow.

B. green, blue, and violet.

C. blue, violet, and red.

D. red and yellow.

8-3In plants, photosynthesis takes place

inside the

a. thylakoids.

b. chloroplasts.

c. photosystems.

d. chlorophyll.

8-3Energy to make ATP in the chloroplast comes most

directly from

a. hydrogen ions flowing through an enzyme in the thylakoid membrane.

b. transfer of a phosphate from ADP.

c. electrons moving through the electron transport

chain.

d. electrons transferred directly from NADPH.

8-3NADPH is produced in light-dependent

reactions and carries energy in the form ofa. ATP.b. high-energy electrons.c. low-energy electrons.d. ADP

8-3

What is another name for the Calvin cycle?

a. light-dependent reactions

b. light-independent reactions

c. electron transport chain

d. photosynthesis

8-3

Which of the following factors does NOT directly affect photosynthesis?

a. wind

b. water supply

c. temperature

d. light intensity

9-1

The raw materials required for cellular respiration are

a. carbon dioxide and oxygen.

b. glucose and water.

c. glucose and oxygen.

d. carbon dioxide and water.

9-1

Glycolysis occurs in the

a. mitochondria.

b. cytoplasm.

c. nucleus.

d. chloroplasts.

9-1

The net gain of ATP molecules after glycolysis is

a. 3 ATP molecules.

b. 2 ATP molecules.

c. 3 pyruvic acid molecules.

d. 4 pyruvic acid molecules

9-1

Fermentation releases energy from food molecules in the absence of

a. oxygen.

b. glucose.

c. NADH.

d. alcohol.

9-1

The first step in fermentation is always

a. lactic acid production.

b. the Krebs cycle.

c. glycolysis.

d. alcohol production.

9-2

The Krebs cycle breaks pyruvic acid down into

a. oxygen.

b. NADH.

c. carbon dioxide.

d. alcohol.

9-2What role does the Krebs cycle play in the

cell?a. It breaks down glucose and releases its

stored energy.b. It releases energy from molecules

formed during glycolysis.c. It combines carbon dioxide and water

into high-energy molecules.d. It breaks down ATP and NADH,

releasing stored energy.

9-2

In eukaryotes, the electron transport chain is located in the

a. cell membrane.

b. inner mitochondrial membrane.

c. cytoplasm.

d. outer mitochondrial membrane.

9-2

To generate energy over long periods, the body must use

a. stored ATP.

b. lactic acid fermentation.

c. cellular respiration.

d. glycolysis.

9-2Which statement correctly describes

photosynthesis and cellular respiration?a. Photosynthesis releases energy, while

cellular respiration stores energy.b. Photosynthesis and cellular respiration

use the same raw materials.c. Cellular respiration releases energy,

while photosynthesis stores energy.d. Cellular respiration and photosynthesis

produce the same products.