Photosynthesis & Cellular Respiration

Biology 2009

Bellwork #22-24-09

1. It is 100 years in the future and you are a research scientist. An enormous volcanic eruption has recently sent huge quantities of dust and ash into the atmosphere. Explain how this event will affect each of the following:

a. Photosynthesis

b. Plant life

c. Animal life

d. Human societies

2. Explain how photosynthesis and respiration are related within an ecosystem

Pre-Lesson Vocabulary

1. Carbohydrates – Compound composed of C1H2O1; used by living things as a source of energy

2. Glucose (p. 30) – C6H12O6 ; The smallest unit that makes up a carbohydrate; A simple sugar

3. Starch (p. 30) – A chain of glucose molecules; used by plants to store food energy

4. Chloroplast – Organelle found in green plants that is used to produce carbohydrates (food) for the plant

Vocabulary

5. Mitochondria – Organelle found in all plant and animal cells that breaks down food to create energy for that organisms

 6. Atom – Smallest unit of matter that cannot be broken down by chemical means

7. Molecule – 2 or more atoms held together by covalent bonds

8. Chemical Reaction – The making and breaking of chemical bonds; written as an equation

Vocabulary

9. Producer – Organism that is able to make its own food (plant); also known as an autotroph

10. Consumer – Organism that gets its energy by eating other organisms; also known as a heterotroph

 11. ATP (adenosine triphosphate) – Molecule used by cells to deliver energy for chemical reactions to take place (similar to a battery)

Energy Flow in the Living World

1. What is the ultimate source of energy for living organisms?

2. Organisms that capture energy directly from sunlight perform the process of

3. These organisms that make their own food using sunlight and are called

4. Organisms that gain their energy from eating plants or other animals for food are called

Sunlight

photosynthesis

producers or autotrophs

Consumers or heterotrophs

5. Label the following as either a producer, consumer, or decomposer.

a. Coyote -

b. Plant -

c. Deer -

6. Look at Figure 5-10 on page 84. All energy can be traced back to the sun.

Therefore, explain how a coyote gets its energy from the sun.

consumer

consumerproducer

The sun provides energy for green plants to make their own food through photosynthesis. When a deer eats a plant, it gets its energy from the carbohydrates in the plant. The coyote then eats the deer, again transferring the energy that began with the sun.

•Draw a picture tracing you and your favorite food back to the energy from the sun. Use Figure 5-10 on page 84 as a guideline.

What did you draw???

Chemistry Review1. Why is water (H2O) considered a molecule?

2. How many atoms of hydrogen and oxygen are in one molecule of H2O? ____ Hydrogen _____ Oxygen

3. Determine the number of each atom in each of the following molecules.

a. 6CO2 = CO2 + CO2 + CO2 + CO2 + CO2 + CO2 = 6 Carbon and 12 Oxygen

b. 6H2O

c. C6H12O6

d. 6O2

e. CO2(OH)3

Chemical Reactions in Living Things1. Chemical reactions within cells drive

2. What is the vocabulary term used to describe

a. starting material-

b. ending material -

 3. True or False: Atoms in the reactants are rearranged to form the products.

a. Na + Cl → NaCl b. 2H2O → 2H2 + O2

c. Na + Cl + Mg → NaCl (NO NO! – Not a chemical reaction!)

 4. True or False: In any chemical reaction, the total number of atoms for each element on the reactants must equal the total number of atoms for each element on the products.

all the activities associated with life

reactant

product

True

True

Chemical Reactions in Living Things

5. Chemical reactions are written in the following form

__________________ → _____________________

6. Review Figure 5-1 and answer the following question. Explain what happens when you eat a baked potato?

When you eat a potato, chemical reactions in your mouth and small intestine convert starch into glucose. Other reactions break down glucose and release energy that your body uses to do work.

Make ProductsReactants

PhotosynthesisWrite the word equation for photosynthesis. (Yes,

you need to know this!)

Write the chemical equation for photosynthesis. (Yes, you need to know this!)

Label the reactants and products in the equation above

How is sunlight used as Energy?

• Sunlight – Sunlight is a form of energy known as electromagnetic radiation. This energy travels as waves – some waves have more energy than others.

How is sunlight used as Energy?• Electromagnetic Spectrum – is made up of

all the possible electromagnetic radiation waves ranging from gamma rays (small waves, but high energy) to radio waves (large wave, but low energy)High

Energy

Low Energy

How is sunlight used as Energy?• Visible Light – The human eye can only

detect a small portion of the electromagnetic radiation emitted from sunlight. The portion we can see is called visible light.

• Have you ever heard of ROYGBIV?R O Y G B I V

Red, Orange, Yellow, Green, Blue, Indigo, Violet

How is sunlight used as Energy?

• Pigment – Molecule that absorbs different colors of light.

• Different pigments can absorb different waves of energy from the electromagnetic spectrum.

• For example, our eyes have the pigment retinal which allows us to absorb only visible light waves.

Why do we see the colors we see?

Our eyes see colors that are being reflected. Therefore, if you look at a piece of blue paper, the pigments of your eyes will absorb the red, green and yellow wavelengths of light and they will reflect the blue wavelengths of light.

Colorblindness

Colorblindness – Affects mostly males

Red green – most common type of colorblindness

ColorblindnessYellow green

Colorblindness

How is sunlight used as Energy?

• Chlorophyll – The main pigment in plants that absorbs red and blue light and reflects green light.

• Chlorophyll is found in the chloroplasts of a plant cell

PhotosynthesisWhere do plants get their reactants?

carbon dioxide –

water –

Chlorophyll –

From the air when humans exhale; it enters through the stoma of plant leaves

Precipitation; it enters through the roots of plants

Found inside the chloroplast of a plant cell

Photosynthesis

What do plants do with the products?

glucose –

oxygen –

Stored (for winter use) or used by the plant as food for energy

Exits through the stoma of plant leaves and enters the air for us to breathe

Bellwork #3 3-3-09Fill in the blank with the correct word.

1. 2 or more atoms held together by covalent bonds: _________

2. Molecule used to give cells energy: ____________

3. An autotroph is another name for a ___________

4. The organelle plants use for photosynthesis: _________

5. The starting material of a chemical reaction: ___________

6. The main pigment in plants that absorbs red and blue light and reflects green light: ___________________

7. A diagram that shows all the possible electromagnetic radiation waves from gamma rays to radio waves: __________

**More on the next slide!!

Bellwork #3 3-3-098. What is the formula for glucose? _____________

9. Determine the number of each atom in the following molecules.

a. 5N2 =

b. 3NaCl =

c. 2C12H24O12 =

d. 4Mg(OH)2=

10. Write the word equation for photosynthesis

11. Write the chemical equation for photosynthesis.

ATP, the Energy Molecule

• ATP = Adenosine Triphosphate; a molecule that supplies the cell with energy

ATP, the energy molecule

• ATP – phosphate group = ADP ; Releases energy for cells to use (like using a battery to power a flashlight)

• ADP + phosphate group = ATP; Takes in or stores energy (recharges the battery)

ATP

• Draw a diagram to show the relationship between ATP and ADP

2 Steps of Photosynthesis: Light Reactions

Oh Boy!!

2 Steps of Photosynthesis: Calvin Cycle

Do we really need to know this???Not until AP Biology…let me give you the simple version

The Steps of Photosynthesis: Simplified

1. Step One: Known as the Light Reactions (sunlight must

be present for this step to occur)

a.Energy is captured from sunlight.

b.This process occurs in plant cells within the

chloroplast organelle by the pigment called

chlorophyll.

c. Water molecules split into H+ and O2. The oxygen

goes into the air.

The Steps of Photosynthesis: Simplified

2. Step Two: Also part of the Light Reactions.

a.Sunlight energy is converted into chemical energy in

the form of adenosine triphosphate or ATP. This

process occurs in which organelle of the plant cell?

Chloroplast

The Steps of Photosynthesis: Simplified

3. Step Three: Known as the Calvin Cycle or Dark Reactions

(this step can happen with or without sunlight).

a. Chemical energy ATP is used to make carbohydrate

molecules

b.What simple carbohydrate is represented as a product in

the chemical reaction for photosynthesis

c. ATP – P = ADP and energy is released to make the

carbohydrates or food for the plant.

Glucose

This ends photosynthesis…Any Questions???

Now on to Cellular

Respiration….

Cellular Respiration

Define Cellular Respiration –

the process by which living things break down food molecules to create energy for moving, thinking, and any other activities associated with life.

Releasing Energy from Organic Molecules

1. Organisms release energy stored as carbohydrates

through a process called cellular respiration

2. True or False Only animals use the process of cellular respiration.

3. True or False Plants and animals use the process of photosynthesis. False, only

plants!!

False, so do plants!!

Cellular Respiration

Write the word equation for cellular respiration (yes you need to know this)

Write the chemical equation for cellular respiration (yes you need to know this)

Photosynthesis vs Cellular Respiration

What do you notice about the equation for photosynthesis vs. the equation for cellular respiration?

a. They are exact opposite equations;b. The reactants for photosynthesis are the products for

cellular respiration c. The products for photosynthesis are the reactants for

cellular respiration

Photosynthesis: Carbon Dioxide + Water → Glucose + Oxygen

C. Respiration: Glucose + Oxygen → Carbon Dioxide + Water

Where do living organisms get the reactants from?

Reactant Animals Plants

Glucose

Oxygen

Food they eat (consume)

Carbohydrates they produce during photosynthesis

From the air when we inhale

From the air through the

stoma

What do living organisms do with the products?

Product Animal Plant

Water

Carbon Dioxide

ATP

Use it to keep hydrated or release it as sweat

Use it for photosynthesis or release it through transpiration

Release it into the air by exhaling

Use it for photosynthesis or release it into the air through the stoma of leaves

Used for energy to drive cell activities needed to sustain life

Used for energy to drive cell activities needed to sustain life

Cellular Respiration

1. What cell organelle converts food energy

(carbohydrates) into energy the cell can use as ATP?

2. True or False? Plant cells and animal cells contain mitochondria.

3. True or False? Plant cells use the process of cellular respiration.

Mitochondria

True

True

Cellular Respiration: Step

11. Step One: Known as

Glycolysis.

a.Glucose is broken in

half and 2 ATP

molecules are

released.

Cellular Respiration: Step 22. Step Two: Known

as Krebs cycle.

a. Glucose is

completely

broken down,

more ATP is

made, and

CO2 is

released.

Cellular Respiration: Step 33. Step Three: Known as Electron Transport Chain.

a.H2O is released and lots of ATP are made. In fact,

34 more ATP are made for each glucose molecule

Why is Oxygen so Important?

1. Aerobic Respiration – cellular respiration that occurs when oxygen is present

2. Anaerobic Respiration – cellular respiration that occurs

when oxygen is NOT present

3. Fermentation – The incomplete breakdown of glucose when oxygen is NOT available