SB3a.

Students will be able to explain the cycling of energy through the

processes of photosynthesis and

respiration

LEQ1 : How is energy cycled through the processes of

photosynthesis and respiration?

Why do organisms need energy?• All organisms require energy to do

work– growth and development

• The original source of all energy on earth is the SUN

How is energy stored?

In living things energy is stored in a molecule of adenosine triphosphate (ATP)

WHAT IS RIBOSE???

Just a thought…

Would you want a tattoo of ATP on your arm???

What is ATP?• Energy storing molecule in organisms

Made of:•5 carbon sugar (ribose)

•Nitrogen compound (adenine)•3 Phosphates

How is energy stored in and released from ATP?

Energy is stored in chemical bonds between phosphates

Energy is released when the bond is broken and one phosphate is released

Adenosine diphosphate (ADP) is produced when the phosphate is

released

Cycling of ATP and ADP

ATP

ADP

En

erg

y re

leasedE

nerg

y

Sto

red

phosphate removed

Organisms break down carbon-based molecules to produce ATP.

• Carbohydrates are the molecules most commonly broken down to make ATP.

–not stored in large amounts

–up to 36 ATP from one glucose molecule

RECALL: MACROMOLECULES

• Fats store the most energy.

– 80 percent of the energy in your body– about 146 ATP from a triglyceride

• Proteins are least likely to be broken down to make ATP.– amino acids not usually needed for energy– about the same amount of energy as a carbohydrate

RECALL: MACROMOLECULES

• Some organisms live in places that never get sunlight.

• In chemosynthesis, chemical energy is used to build carbon-based molecules.– similar to photosynthesis– uses chemical energy

instead of light energy

RECALL: CHEMOSYNTHESIS

What are the three main uses for ATP?

1. Transports needed substances across the cell membrane

– Active Transport

2. Activating metabolic reactions– All chemical reactions in the body

3. Mechanical work – Moving muscles

Summarizer

Explain to your neighbor how energy is converted between ATP and ADP.

HINT: Make sure to use the word phosphate in your explanation.

STAY ON TASK… ONLY TALK ABOUT THIS SUMMARIZER!!!

Photosynthetic organisms are producers.

• Producers make their own source of chemical energy.

• Plants use photosynthesis and are producers.

• Photosynthesis captures energy from sunlight to make sugars.

Chlorophyll is a

molecule that absorbs

light energy.

chloroplast

leaf cell

leaf

In plants, chlorophyll isfound in organellescalled chloroplasts.

• Photosynthesis takes place in two parts of chloroplasts.– grana (thylakoids)– stroma

chloroplast

stroma

grana (thylakoids)

Each part of the chloroplast is

responsible for a specific reaction.

– take place in grana (thylakoids)– water and sunlight are needed– chlorophyll absorbs energy– energy is transferred along thylakoid membrane then to

light-independent reactions (ATP is used to drive the 2nd reaction.)

– oxygen is released

The 1st ReactionLight Dependent Reaction

– take place in stroma– needs carbon dioxide from atmosphere– use energy to build a sugar in a cycle of

chemical reactions (ATP)

This is also referred to as the CALVIN CYCLE!!!

The 2nd StepLight Independent Reaction

The equation for the overall process is:

6CO2 + 6H2O C6H12O6 + 6O2

C6H12O6

granum (stack of thylakoids)

thylakoid

sunlight

1 six-carbon sugar

6H2O

6CO2

6O2

chloroplastchloroplast1

2

43

energy

stroma (fluid outside the thylakoids)

Reactants of Photosynthesis

1. Radiant energy– Sunlight is absorbed by the chloroplasts

in the leaves of the plant

2. Carbon dioxide– Absorbed by the leaves of the plant

3. Water– Absorbed from the soil by the roots of the

plant

Products of Photosynthesis

1. Sugar (C6H12O6 = glucose)– Produced in the leaves of the plant and is

transported to the rest of the plant for chemical energy

– What is the suffix for identifying a sugar?

2. Oxygen– Is released from the leaves of the plant into

the atmosphere

Summarizer

1. Write out the equation of photosynthesis.

2. Switch papers with your neighbor and add any additional information.

Why is the release of oxygen by plants an important function?

How does it affect us?

How do animals get their energy?

Animals extract energy from the food they consume

through the process of

cellular respiration

What is Cellular Respiration?

• Process in which organisms release stored energy from food.

• Formula:

6O2 + C6H12O6 energy + 6CO2 + 6H2O

Two types of Cellular Respiration

1. Aerobic Respiration Requires Oxygen

2. Anaerobic Respiration Does NOT require Oxygen

Aerobic Respiration

• Occurs in the presence of oxygen

• Involves 3 steps: Glycolysis, Krebs Cycle, and Electron Transport Chain

• Complete breakdown of sugar

• Produces: ATP + carbon dioxide

• More efficient because it produces a greater quantity of ATP

Glycolysis

– anaerobic process (does not require oxygen)– takes place in cytoplasm– splits glucose into two three-carbon molecules– produces two ATP molecules

1st step of AEROBIC respiration

-products are transferred to the mitochondria for the 2nd step (the Kreb’s Cycle)

• The Krebs cycle transfers energy to an electron transport chain.– takes place in

mitochondrial matrix– breaks down three-carbon

molecules from glycolysis

– makes a small amount of ATP

– releases carbon dioxide– transfers energy-carrying

molecules

6H O2

6CO 2

6O 2

mitochondrionmitochondrion

matrix (area enclosedby inner membrane)

inner membrane

ATP

ATP

energy

energy from glycolysis

1

2

4

3

and

and

and

Krebs Cycle

2nd step of AEROBIC respiration

6H O2

6CO 2

6O 2

mitochondrionmitochondrion

matrix (area enclosedby inner membrane)

inner membrane

ATP

ATP

energy

energy from glycolysis

1

2

4

3

and

and

and

The electron transport chain produces a large amount of ATP.

– takes place in inner membrane

– energy transferred to electron transport chain

– oxygen enters process

– 34 ATP produced

– water released as awaste product

Electron Transport

3rd step of AEROBIC respiration

Photosynthesis vs. Respiration

• They are opposite processes

• Reactants for one process are the products for the other

• Two processes together maintain the balance of life on earth

• The equation for the overall process is:

C6H12O6 + 6O2 6CO2 + 6H2O

Anaerobic Respiration• Occurs in the absences of oxygen

– Body is deprived of enough oxygen to maintain aerobic reactions

• Involves 2 steps: Glycolysis, and Fermentation

• Incomplete breakdown of sugar

• Produces: ATP + carbon dioxide + alcohol/lactic acid

• Not as efficient as aerobic respiration (produces less ATP)

Fermentation allows the production of a small amount

of ATP without oxygen.

• Fermentation allows glycolysis to continue making ATP when oxygen is unavailable.

• Fermentation does not produce ATP.

• Lactic acid fermentation occurs in muscle cells.– glycolysis splits glucose into two pyruvate molecules– pyruvate and NADH enter fermentation– energy from NADH converts pyruvate into lactic acid– NADH is changed back into NAD+

• NAD+ is recycled to glycolysis

Fermentation and its products are important in several ways.

• Alcoholic fermentation is similar to lactic acid fermentation.– glycolysis splits glucose and the products enter fermentation

– energy from NADH is used to split pyruvate into an alcohol and carbon dioxide

– NADH is changed back into NAD+

– NAD+ is recycled to glycolysis

Alcoholic Fermentation is used in food production by yeast and microorganisms to produce:

– yogurt

– cheese

– bread

Lactic Acid Fermentation occurs in animals.

It is caused by the buildup of lactic acids in muscle cells.

-soreness

-burning

Summarizer

What is the total amount of ATP produced from one molecule of glucose during aerobic respiration?

Summarizer

How can you tell if your body is going through aerobic or anaerobic respiration when you are working out?

Summarizer:Complete the chart below on the steps of aerobic

respiration.

Use the termsGlycolysis

ETCGlucose

Carbon DioxideOxygenWater

Krebs Cycle 2 ATP

34 ATP

Complete the chart of anaerobic respiration

below: Use the Terms:

Glucose

2ATP

Fermentation

Lactic acid

Alcoholic

Glycolysis

Yeast

Microorganisms

Animals

Summarizer

Summarizer

Use the chart to answer the Essential Question:

How is energy cycled through the processes of photosynthesis and respiration?

Comparison Chart:Photosynthesis vs. Respiration

Photosynthesis Cellular Respiration

Function

Location

Reactants

Products

Chemical Equation

Summarizer