Cell Energy:Cell Energy:Photosynthesis & Respiration Photosynthesis & Respiration

Chapter 3:2

Chapter 7:1

How Does a Plant Make It’s Own How Does a Plant Make It’s Own Food?Food?

Plants use carbon dioxide (Plants use carbon dioxide (COCO22), ),

water (water (HH22OO), and ), and sun’s energysun’s energy to to

make food.make food. This is called “This is called “photosynthesisphotosynthesis” ” The food gives plants The food gives plants energyenergy Animals get the energy stored in Animals get the energy stored in

plantsplants when they eat them. when they eat them.

Why it matters: Understanding Why it matters: Understanding

how plants & animals get energyhow plants & animals get energy

to to growgrow & & developdevelop is an is an important part of biology.important part of biology.

How Do Plants Get Energy From Sun? How Do Plants Get Energy From Sun? Plants have Plants have pigmentspigments that that

absorb energy from lightabsorb energy from light ChlorophyllChlorophyll (found in (found in

chloroplasts) is the pigment chloroplasts) is the pigment used in photosynthesisused in photosynthesis

What “Food” do Plants Make?What “Food” do Plants Make?

The “food” plants The “food” plants make is a make is a sugarsugar called called glucoseglucose (C(C66HH1212OO66).).

Glucose and Glucose and oxygen oxygen (O(O22) are made during ) are made during

photosynthesis.photosynthesis.

How Do Organisms Get Energy How Do Organisms Get Energy From Food?From Food?

Animals cannot make their Animals cannot make their own foodown food like plants can. like plants can. But, BOTH plants and animals must But, BOTH plants and animals must break downbreak down (digest) (digest)

food in order to get food in order to get energyenergy from it (so they can live, grow, from it (so they can live, grow, & develop)& develop)

Cells do this Cells do this 22 ways: cellular respiration and fermentation ways: cellular respiration and fermentation

Cellular Respiration & FermentationCellular Respiration & Fermentation

Cellular Respiration uses Cellular Respiration uses oxygenoxygen (O (O22) to break down food) to break down food Fermentation does Fermentation does not not use use oxygenoxygen Cellular respiration releases Cellular respiration releases more energymore energy from food than from food than

fermentation.fermentation. So most So most eukaryoteseukaryotes

(ex: plants & animals) (ex: plants & animals) get their energy through get their energy through cellular respiration cellular respiration

Cellular RespirationCellular Respiration

Cellular Respiration = Cellular Respiration = chemical process that chemical process that happens in happens in cells and cells and produces (ATP produces (ATP energy)energy)

In eukaryotes, it In eukaryotes, it happens mostly in the happens mostly in the mitochondriamitochondria

Process of Cellular RespirationProcess of Cellular Respiration Food (glucose) is broken down into COFood (glucose) is broken down into CO22 and H and H22O and O and

energy is energy is releasedreleased CC66HH1212OO66 + 6 + 6 OO22 6 6 COCO22 + 6 + 6 HH22OO + + energyenergy (ATP) (ATP)

This energy can be used for:This energy can be used for: Keeping a constant Keeping a constant body temperaturebody temperature StorageStorage (ATP) - to be used later for things like growth (ATP) - to be used later for things like growth

What Do You Notice?What Do You Notice?

Check It Out!Check It Out! Did you notice that cellular respiration is just the Did you notice that cellular respiration is just the oppositeopposite of of

photosynthesis?photosynthesis? Photosynthesis:Photosynthesis:

sunlightsunlight

6CO6CO22 + 6H + 6H

22O ----------> CO ----------> C66HH1212OO6 6 + 6O+ 6O

22 carbon dioxide water chlorophyll glucose oxygencarbon dioxide water chlorophyll glucose oxygen

Respiration:Respiration:

Equation Facts:Equation Facts: Word equations – are written with wordsWord equations – are written with words Chemical equations – are written with chemical symbolsChemical equations – are written with chemical symbols You read the arrows as yields (or equals)You read the arrows as yields (or equals) The words above and below the arrows are The words above and below the arrows are USEDUSED BUT BUT

UNCHANGEDUNCHANGED The substances on the left side of the arrow are called The substances on the left side of the arrow are called

reactants (or raw materials) of the chemical reactionreactants (or raw materials) of the chemical reaction The substances on the right side of the arrow are called The substances on the right side of the arrow are called

products of the chemical reaction (they are what is made)products of the chemical reaction (they are what is made) Know the substances by their word and their chemical Know the substances by their word and their chemical

symbolssymbols

We get the carbon dioxide and oxygen cycle from these two processes!

CARBON DIOXIDE AND OXYGEN CYCLE

FermentationFermentation Happens when cells cannot Happens when cells cannot

get the get the oxygenoxygen they need for they need for cellular respirationcellular respiration

Fermentation is a way to getFermentation is a way to get energy energy when oxygen isn’t when oxygen isn’t availableavailable

Yeast is an example of Yeast is an example of fermentationfermentation

This type of energy is This type of energy is lessless than what you get during than what you get during respirationrespiration

Ex: During fast races you Ex: During fast races you might get a might get a burning feelingburning feeling in you in you leg musclesleg muscles because of because of a build up of lactic acid (made a build up of lactic acid (made during fermentation)during fermentation)

Today’s Learning GoalsToday’s Learning Goals In plants, chloroplasts capture In plants, chloroplasts capture

energy from the sun in order energy from the sun in order to make food during to make food during photosynthesisphotosynthesis

Cells release energy from food Cells release energy from food through either cellular through either cellular respiration of fermentationrespiration of fermentation

Why it matters: Understanding Why it matters: Understanding how plants & animals get how plants & animals get energy to grow & develop is an energy to grow & develop is an important part of biology.important part of biology.