transformation of energy energy is the ability to do work. how organisms obtain energy – chapter...

Transformation of Energy

Energy is the ability to do work.

How Organisms Obtain Energy – Chapter 8

Cellular Energy

Thermodynamics is the study of the flow and transformation of energy in the universe.

Section 1

Laws of Thermodynamics

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

How Organisms Obtain Energy

Cellular Energy

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

Section 1

Autotrophs vs. Heterotrophs

Use light energy from sun to make own food

Obtain energy from other organisms

ALL ORGANISMS NEED ENERGY TO CARRY OUT LIFE FUNCTIONS AND MUST RELEASE ENERGY FROM SUGARS

AND OTHER COMPOUNDS!!

Section 1

Metabolism - all of the chemical reactions in a cell

Two types of metabolic pathways1. Anabolic – Take in energy to build

large molecules

2. Catabolic – Release energy when breaking down large molecules

How Organisms Obtain Energy

Cellular EnergySection 1

• Photosynthesis—light energy from the Sun is converted to chemical energy for use by the cell

• Cellular respiration—organic molecules are broken down to release energy for use by the cell

Ribose (5-carbon sugar)

Adenosine Triphosphate (ATP)One of principal chemical compounds

that cells use to store and release energy

Adenine

3 Phosphate groups

ATP

ADP ATP

Energy

Energy

Partiallycharged battery

Fullycharged battery

Adenosine Diphosphate (ADP) + Phosphate

Adenosine Triphosphate (ATP)

How is energy stored and released?

What is ATP used for in the cell?

PhotosynthesisProcess of turning light energy from

the sun into chemical energy

Overview of Photosynthesis

Photosynthesis occurs in two phases.

Cellular Energy

Light-dependent reactions

Light-independent reactions or the Calvin Cycle.

Photosynthesis

Section 2

Photosynthesis: Overview

Chloroplast

LightH2O

O2

CO2

Sugars

NADP+

ADP + P

Calvin Cycle

Light- dependent reactions

Calvin cycle

Photosynthesis: OverviewLIGHT-DEPENDENT REACTIONS

Require light / use energy from light to produce oxygen gas and convert ADP and NADP+ into the

energy carriers ATP and NADPH

CALVIN CYCLE

Does NOT require light / uses ATP and NADPH from light-dependent reactions to produce high-energy

sugars that can be stored for a long time

Electron Carriers

When a potato is very hot, you wouldn’t dare grab it with your bare hand, rather you use an oven mitt to carry the potato. As the potato cools, you no longer need the oven mitt.

This is similar to an electron carrier. Once an electron receives energy from the sun, it is considered a “high-energy electron.” The electron does not travel on its own from place to place. Another substance (in this case NADP) carries the electron to its destination. As the electron loses it’s high energy levels, it no longer needs an electron carrier.

An electron carrier then is “a compound that can accept a pair of high-energy electrons and transfer them, along with most of their energy, to another molecule.”

Light-Dependent Reactions

2H2O

+ O2

ATP synthase

ADP2 NADP+

2 NADPH2

Calvin Cycle

12 NADPH

12

12 ADP

12 NADP+

5-Carbon MoleculesRegenerated

6

6 ADP

Electron Transport

Light energy excites electrons in the photosystems and also causes a water molecule to split, releasing an electron and O2 is released as a waste product.

Cellular Energy

Photosynthesis

Section 2

Cellular Energy

Photosynthesis

Phase Two: The Calvin Cycle

In the second phase of photosynthesis, called the Calvin cycle, energy is stored in organic molecules such as glucose.

Section 2

Cellular Energy

Photosynthesis

CO2 molecules combine with a 6 carbon molecule with an enzyme.

The chemical energy stored in ATP and NADPH is transferred to make a glucose molecule.

Section 2

Cellular Energy

Photosynthesis

Alternative Pathways - in hot, dry environments plants have adapted to a different way to perform photosynthesis

C4 plants – are able to make glucose in different cells. Ex: Corn and sugarcane

CAM plants – are able to make glucose at different time of the day. Ex: Pineapples and cati

Section 2

Overview of Cellular Respiration

Organisms obtain energy in a process called cellular respiration.

Cellular Respiration

Cellular Energy

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

Section 3


Cellular Energy

Cellular respiration occurs in three main parts. Glycolysis Krebs Cycle Electron Transport

Section 3

GlycolysisProcess in which one molecule of

glucose is broken in half, producing pyruvic acid and a small amount of

energy in the cytoplasm

2 ADP 4 ADP 4 ATP

2 Pyruvicacid

2 ATP

2NAD+2

NET GAIN OF HOW MANY ATP MOLECULES?

Krebs Cycle


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.

Section 3


Cellular Energy

The net yield from the Krebs cycle:

6 CO2 molecules 2 ATPs 8 NADH 2 FADH2

Section 3

Krebs Cycle

CoA

CoA

CO2

NAD

NADH

ADPATP P

FAD

FADH2


Cellular Energy

Electron Transport Chain

Final step in the breakdown of glucose

Point at which ATP is produced

Produces about 24 ATP

Section 3

Electron Transport ChainUses high-energy electrons from the Krebs Cycle to convert ADP into ATP

ATP

ATP synthase

Channel


Cellular Energy

Anaerobic Respiration

The anaerobic pathway that follows glycolysis

Two main types

Lactic acid fermentation

Alcohol fermentation


Section 3

FermentationReleases energy from food by

producing ATP in the absence of oxygen

WHY IS THIS IMPORTANT TO CELLS?

Two Types of FermentationALCOHOLIC

Used by yeasts and microorganisms, producing alcohol and carbon dioxide (as well as NAD+)

LACTIC ACID

Conversion of pyruvic acid into lactic acid (as well as NAD+)

NO OXYGEN! NAD+

PRODUCED FOR BOTH!

Cellular Energy

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Formative Test Questions

Chapter Assessment Questions

Standardized Test Practice

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1. A2. B3. C4. D

CDQ 1

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?

Cellular Energy


Chapter

1. A2. B3. C4. D

CDQ 2

Cellular Energy


Chapter

A. photosynthesis

B. cellular respiration

C. homeostasis

D. fermentation

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

1. A2. B3. C4. D

CDQ 3

Cellular Energy


Chapter

A. NADPH

B. ATP

C. chloroplast

D. glucose

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

1. A

2. B

FQ 1

Cellular EnergyChapter

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

Section 1 Formative Questions

1. A

2. B

FQ 2



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

A. true

B. false

1. A

2. B

3. C

4. D

FQ 3



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.

1. A

2. B

3. C

4. D

FQ 4



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?

1. A

2. B

3. C

4. D

FQ 5


A. chloroplasts

B. Golgi apparatus

C. mitochondria

D. vacuoles

Where in the plant cell does photosynthesis take place?


1. A

2. B

3. C

FQ 6



A. 400-500 nm

B. 500-600 nm

C. 600-700 nm

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

1. A

2. B

3. C

4. D

FQ 7



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?

1. A

2. B

3. C

4. D

FQ 8



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?

1. A

2. B

3. C

4. D

FQ 9


A. to make ATP

B. to process H2O

C. to store glucose

D. to deliver oxygen

What is the overall purpose of cellular respiration?


1. A

2. B

3. C

4. D

FQ 10


Which represents the general sequence of cellular respiration?

A. TCA cycle chemiosmosis glycolysisB. glycolysis Krebs cycle electron transportC. electron absorption catalysis

phosphorylationD. aerobic pathway anaerobic pathway

fermentation


1. A

2. B

3. C

FQ 11


A. glycolysis

B. Krebs cycle

C. electron transport

Which stage of cellular respiration is the anaerobic process?


1. A

2. B

3. C

4. D

FQ 12


A. CoA

B. CO2

C. FADH2

D. NADH

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


1. A

2. B

3. C

4. D

CAQ 1


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


1. A

2. B

3. C

4. D

CAQ 2



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

A. H2O

B. O2

C. CO

D. CO2

1. A

2. B

3. C

4. D

CAQ 3



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

1. A

2. B

STP 1


Which metabolic process is photosynthesis?

A

B


1. A

2. B

3. C

4. D

STP 2



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

1. A

2. B

3. C

4. D

STP 3



Which molecule helps provide the energy that drives this cycle?

A. 3-PGA

B. CO2

C. NADPH

D. rubisco

1. A

2. B

3. C

4. D

STP 4



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+

1. A

2. B

3. C

4. D

STP 5



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.

1. A

2. B

3. C

4. D

STP 6



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

1. A

2. B

3. C

4. D

STP 7



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

Glencoe Biology Transparencies

Chapter

Cellular Energy

Image Bank

Chapter

energy

thermodynamics

metabolism

Photosynthesis

cellular respiration

adenosine triphosphate (ATP)


Vocabulary

Section 1

thylakoid

granum

stroma

pigment

NADP+

Calvin cycle

rubisco


Vocabulary

Section 2

anaerobic process

aerobic respiration

aerobic process

glycolysis

Krebs cycle

fermentation


Vocabulary

Section 3

Cellular Energy

ATP

The Calvin Cycle

Visualizing Electron Transport

The Krebs Cycle (Citric Acid Cycle)

Animation

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