ch 8 ~ cellular energy section 1: how organisms obtain energy section 2: photosynthesis section 3:...

Ch 8 ~ Cellular Energy

Section 1: How Organisms Obtain Energy

Section 2: Photosynthesis

Section 3: Cellular Respiration

Transformation of Energy

Energy - ability to do work.

8.1 How Organisms Obtain EnergyCellular Energy

Thermodynamics - study of flow & transformation of energy in universe.

Laws of Thermodynamics

First law —energy converted from one form to another, but cannot be created nor destroyed.

Cellular Energy

Second law —energy cannot be converted without the loss of energy

Autotrophs -make their own food.

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Heterotrophs -need to ingest food to obtain energy.

Metabolism - All chemical reactions in a cell

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Photosynthesis—light energy from Sun converts to chemical energy for use by cell

Cellular respiration—organic molecules (CHO, lipid, Pro) broken down to release energy for use by cell

“catabolism”, or catabolic pathway

ATP: The Unit of Cellular Energy

ATP releases energy when bond btwn 2nd & 3rd P group is broken, forming molecule called adenosine diphosphate (ADP) & 1 free P group.

Cellular Energy

ATP

energy

thermodynamics

metabolism

Photosynthesis

cellular respiration

adenosine triphosphate (ATP)

Cellular Energy

Vocabulary

Section 8.1

FQ 4

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

8.1 Formative Questions

A B C D

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A. It captures light energy from the sun.

B. It is produced in anabolic pathways.

C. It stores and releases chemical energy.

D. It converts mechanical energy to thermal energy.

Why is adenosine triphosphate (ATP) such an important biological molecule?

FQ 1

1. A2. B

Cellular EnergyChapter 8

Which law of thermodynamics explains why the ladybug receives the least amount of usable energy?

A. the first law of thermodynamics

B. the second law of thermodynamics A B

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8.1 Formative Questions

FQ 2

1. A2. B

Cellular EnergyChapter 8

A B

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8.1 Formative Questions

All of the energy from the food you eat comes from the sun.

A. true

B. false

FQ 3

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

8.1 Formative Questions

A B C D

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Why is cellular respiration a catabolic pathway?

A. Energy is used to form

glucose and oxygen.

B. Energy is converted from

water to carbon dioxide.

C. Energy that is lost is

converted to thermal energy.

D. Energy is released by the

breakdown of molecules.

Overview of Photosynthesis

Photosynthesis occurs in 2 phases:

Cellular Energy

Light-dependent reactions

Light-independent reactions

8.2 Photosynthesis

Phase One: Light Reactions

Absorption of light is 1st step in photosynthesis.

Cellular Energy

Chloroplasts capture light energy.

Chloroplasts

capture light energy; mainly in leaf cells

thylakoids – form flat, sac-like membranes in stacks, or grana- light-dependent chem rx take place in

thylakoids

Stroma – fluid-filled space outside grana- light-independent chem rx takes place in stroma

Cellular Energy

Pigments absorb light; found in thylakoid membranes

Diff pigments absorb diff wavelengths of light.

Major pigmentschlorophylls a & b, carotenoidsabsorb violet-blue light and reflect green (chlorophylls) or red/yellow/orange (carotenoids)

Cellular Energy

Electron Transport Chain

Light energy excites e- in photosystem II causing water molecule to split & 3 events to occur:

1. releasing e- into electron transport system (ETC)

2. releasing H+ into thylakoid space

3. produce O2 as waste product.

Excited e- move from photosystem II to an electron-acceptor molecule in thylakoid membrane.

Electron-acceptor molecule (NADH or FAD) transfers e- along a series of electron-carriers to photosystem I.

Cellular Energy

Cellular EnergyPhotosystem I transfers the electrons to protein called ferrodoxin.

Ferrodoxin transfers the electrons to the electron carrier NADP+, forming the energy-storing molecule NADPH.

Cellular Energy

Phase Two: The Calvin CycleIn 2nd phase of photosynthesis, called Calvin cycle, energy is stored in organic molecules such as glucose.Why?

Cellular EnergyChapter 8

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Calvin Cycle

WHY?

Because NADPH & ATP provide cells with LOTS of energy, but not for a long time. So, 2nd phase of photosynthesis stores energy in glucose.

Processes in Calvin Cycle6 CO2 molecules combine w/ 6 x 5-C

compounds to form 12 x 3-C molecules called 3-PGA.

The chemical energy stored in ATP & NADPH is transferred to the 3-PGA molecules to form high-energy molecules called G3P.

Cellular Energy 2 G3P molecules leave the cycle to be used for production of

glucose and other organic compounds.

Enzyme called rubisco converts remaining 10 G3P molecules into 5-C molecules called RuBP.

These molecules combine with new CO2 molecules to continue the Calvin cycle.

thylakoid

granum

stroma

pigment

NADP+

Calvin cycle

rubisco

Cellular EnergyChapter 8

Vocabulary

Section 2

FQ 5

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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A. chloroplasts

B. Golgi apparatus

C. mitochondria

D. vacuoles

Where in the plant cell does photosynthesis take place?

8.2 Formative Questions

FQ 6

1. A

2. B

3. C

Cellular EnergyChapter 8

8.2 Formative Questions

A. 400-500 nm

B. 500-600 nm

C. 600-700 nm

Which range of wavelengths is reflected by chlorophylls a and b?

A B C

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FQ 7

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

8.2 Formative Questions

A. absorption

B. chemiosmosis

C. electron transport

D. C2 pathway

Which mechanism of photosynthesis uses the movement of hydrogen ions (H+) across a concentration gradient to synthesize ATP?

A B C D

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FQ 8

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

8.2 Formative Questions

A B C D

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A. They accelerate photosynthesis.

B. They release more oxygen.

C. They help the plant conserve water.

D. They reduce the requirement for ATP.

How are the C4 pathway and the CAM pathway

an adaptive strategy for some plants?

Overview of Cellular Respiration

Organisms obtain energy in a process called cellular respiration.

8.3 Cellular Respiration

Cellular Energy

The equation for cellular respiration is the opposite of the equation for photosynthesis.

Chapter 8

8.3 Cellular Respiration

Cellular Energy

Cellular respiration occurs in two main parts.

Glycolysis

Aerobic respiration

Chapter 8

Glycolysis

Glucose is broken down in the cytoplasm through the process of glycolysis.

8.3 Cellular Respiration

Cellular Energy

Two molecules of ATP and two molecules of NADH are formed for each molecule of glucose that is broken down.

Chapter 8

Krebs Cycle

Glycolysis has a net result of two ATP and two pyruvate.

8.3 Cellular Respiration

Cellular Energy

Most of the energy from

the glucose is still contained in

the pyruvate.

The series of reactions

in which pyruvate is broken

down into carbon dioxide is called

the Krebs cycle.

Chapter 8

8.3 Cellular Respiration

Cellular Energy

The net yield from the Krebs cycle is six CO2 molecules, two ATP, eight NADH, and two FADH2.

Chapter 8

Cellular EnergyChapter 8

8.3 Cellular Respiration

Cellular Energy

Electron Transport

Final step in the breakdown of glucose

Point at which ATP is produced

Produces 24 ATP

Chapter 8

8.3 Cellular Respiration

Cellular Energy

Anaerobic Respiration

The anaerobic pathway that follows glycolysis

Two main types

Lactic acid fermentation

Alcohol fermentation

Cellular Respiration

Chapter 8

anaerobic process

aerobic respiration

aerobic process

glycolysis

Krebs cycle

fermentation

Cellular EnergyChapter 8

Vocabulary

Section 3

FQ 9

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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A. to make ATP

B. to process H2O

C. to store glucose

D. to deliver oxygen

What is the overall purpose of cellular respiration?

8.3 Formative Questions

FQ 10

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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Which represents the general sequence of cellular respiration?

A. TCA cycle chemiosmosis glycolysis

B. glycolysis Krebs cycle electron transport

C. electron absorption catalysis phosphorylation

D. aerobic pathway anaerobic pathway fermentation

8.3 Formative Questions

FQ 11

1. A

2. B

3. C

Cellular EnergyChapter 8

A B C

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A. glycolysis

B. Krebs cycle

C. electron transport

Which stage of cellular respiration is the anaerobic process?

8.3 Formative Questions

FQ 12

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A. CoA

B. CO2

C. FADH2

D. NADH

Which molecule generated by the Krebs cycle is a waste product?

A B C D

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8.3 Formative Questions

Cellular Energy

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Chapter 8

CDQ 1

1. A2. B3. C4. D

A B C D

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A. Energy cannot be converted or destroyed.

B. Energy can be converted and destroyed.

C. Energy can be converted but not destroyed.

D. Energy can be destroyed but not converted.

Which statement describes the law of conservation of energy?

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Chapter Diagnostic Questions

Chapter 8

CDQ 2

1. A2. B3. C4. D

A B C D

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Cellular Energy

Chapter Diagnostic Questions

Chapter 8

A. photosynthesis

B. cellular respiration

C. homeostasis

D. fermentation

In which metabolic process are molecules broken down to produce carbon dioxide and water?

CDQ 3

1. A2. B3. C4. D

A B C D

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Cellular Energy

Chapter Diagnostic Questions

Chapter 8

A. NADPH

B. ATP

C. chloroplast

D. glucose

At the end of the Calvin cycle, where is energy stored?

CAQ 1

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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Look at the following figure. Which part of the chloroplast is a sac-like membrane arranged in stacks?

A. grana

B. stroma

C. thylakoids

D. Golgi apparatus

Chapter Assessment Questions

CAQ 2

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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Chapter Assessment Questions

During the Krebs cycle, pyruvate is broken down into what compound?

A. H2O

B. O2

C. CO

D. CO2

CAQ 3

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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Chapter Assessment Questions

Look at the following figure. Which molecule is released when ATP becomes ADP?

A. phosphate group

B. water molecule

C. ribose sugar

D. energy cells

STP 1

1. A

2. B

Cellular EnergyChapter 8

A B

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Which metabolic process is photosynthesis?

A

B

Standardized Test Practice

STP 2

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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Standardized Test Practice

At the beginning of photosynthesis, which molecule is split to produce oxygen (O2) as

a waste product?

A. CO2

B. H2O

C. C6H12O6

D. 3-PGA

STP 3

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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Standardized Test Practice

Which molecule helps provide the energy that drives this cycle?

A. 3-PGA

B. CO2

C. NADPH

D. rubisco

STP 4

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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Standardized Test Practice

Which product of the Calvin cycle is used for the production of glucose and other organic compounds?

A. ADP

B. CO2

C. G3P

D. NADP+

STP 5

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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Standardized Test Practice

What is the final step of cellular respiration?

A. O2 and H+ form H2O.

B. Electrons and H2O generate ATP.

C. C6H12O6 is broken down into CO2.

D. NADH and FADH2 gain electrons.

STP 6

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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Standardized Test Practice

What prevents pyruvate from entering the Krebs cycle and instead results in this pathway?

A. a buildup of CO2

B. a lack of oxygen

C. an excess of glucose

D. an increased demand for ATP

STP 7

1. A

2. B

3. C

4. D

Cellular EnergyChapter 8

A B C D

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Standardized Test Practice

Which is not a process that occurs in both cellular respiration and glycolysis?

A. chemiosmosis

B. electron transport

C. glycolysis

D. production of G3P

Cellular Energy

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Cellular Energy

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Cellular Energy

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Chapter 8

Cellular EnergyChapter 8

Cellular EnergyChapter 8

Cellular EnergyChapter 8