LIFE SCIENCE

1. Cell Energy:Cell Energy:
Photosynthesis & RespirationPhotosynthesis & Respiration
Chapter 5, Section 1

2. Today’s Learning GoalsToday’s Learning Goals
 In plants,In plants, chlorophyllchlorophyll (found in(found in
chloroplasts) captures energychloroplasts) captures energy
from the sun in order to makefrom the sun in order to make
foodfood during photosynthesisduring photosynthesis
 Cells releaseCells release energyenergy from foodfrom food
through eitherthrough either cellularcellular
respirationrespiration oror fermentationfermentation
 Why it matters: UnderstandingWhy it matters: Understanding
how plants & animals gethow plants & animals get
energy toenergy to growgrow && developdevelop is anis an
important part of biology.important part of biology.

3. How Does a Plant Make It’s OwnHow Does a Plant Make It’s Own
Food?Food?
 Plants use carbon dioxide (Plants use carbon dioxide (COCO22), water (), water (HH22OO), and), and sun’ssun’s
energyenergy to make food.to make food.
 This is called “This is called “photosynthesisphotosynthesis””
 The food gives plantsThe food gives plants energyenergy
 Animals get theAnimals get the
energy stored inenergy stored in
plantsplants when theywhen they
eat them.eat them.

4. How Do Plants Get Energy From Sun?How Do Plants Get Energy From Sun?
 Plants havePlants have pigmentspigments thatthat
absorb energy from lightabsorb energy from light
 ChlorophyllChlorophyll (found in(found in
chloroplasts) is the pigmentchloroplasts) is the pigment
used in photosynthesisused in photosynthesis

5. What “Food” do Plants Make?What “Food” do Plants Make?
 The “food” plantsThe “food” plants
make is amake is a sugarsugar
called glucosecalled glucose
(C(C66HH1212OO66).).
 Glucose andGlucose and oxygenoxygen
(O(O22) are made during) are made during
photosynthesis.photosynthesis.

6. How Do Organisms Get EnergyHow Do Organisms Get Energy
From Food?From Food?
 Animals cannot make theirAnimals cannot make their own foodown food like plants can.like plants can.
 But, BOTH plants and animals mustBut, BOTH plants and animals must break downbreak down
(digest) food in order to get(digest) food in order to get energyenergy from it (so theyfrom it (so they
can live, grow, & develop)can live, grow, & develop)
 Cells do thisCells do this 22 ways: cellular respiration andways: cellular respiration and
fermentationfermentation

7. Cellular Respiration & FermentationCellular Respiration & Fermentation
 Cellular Respiration usesCellular Respiration uses oxygenoxygen (O(O22) to break down food) to break down food
 Fermentation doesFermentation does notnot useuse oxygenoxygen
 Cellular respiration releasesCellular respiration releases more energymore energy from food thanfrom food than
Fermentation.Fermentation.
 So mostSo most eukaryoteseukaryotes
(ex: plants & animals)(ex: plants & animals)
get their energy throughget their energy through
cellular respirationcellular respiration

8. Cellular RespirationCellular Respiration
 Cellular Respiration =Cellular Respiration =
chemical process thatchemical process that
happens inhappens in cellscells
 In prokaryotes, itIn prokaryotes, it
happens in thehappens in the cellcell
membranesmembranes
 In eukaryotes, itIn eukaryotes, it
happens mostly in thehappens mostly in the
mitochondriamitochondria

9. Process of Cellular RespirationProcess of Cellular Respiration
 Food (glucose) is broken down into COFood (glucose) is broken down into CO22 and Hand H22O andO and
energy isenergy is releasedreleased
 CC66HH1212OO66 + 6+ 6 OO22  66 COCO22 + 6+ 6 HH22OO ++ energyenergy (ATP)(ATP)
 This energy can be used for:This energy can be used for:
 Keeping a constantKeeping a constant body temperaturebody temperature
 StorageStorage (ATP) - to be used later for things like growth(ATP) - to be used later for things like growth

10. What Do You Notice?What Do You Notice?

11. Check It Out!Check It Out!
 Did you noticeDid you notice
that cellularthat cellular
respiration is justrespiration is just
thethe oppositeopposite ofof
photosynthesis?photosynthesis?

12. FermentationFermentation
 Happens when cells cannotHappens when cells cannot
get theget the oxygenoxygen they need forthey need for
cellular respirationcellular respiration
 Fermentation is a way to getFermentation is a way to get
energyenergy when oxygen isn’twhen oxygen isn’t
availableavailable
 Ex: In short, fast races youEx: In short, fast races you
might get amight get a burning feelingburning feeling
in youin you leg musclesleg muscles because ofbecause of
a build up of lactic acid (madea build up of lactic acid (made
during fermentation)during fermentation)

13. Pop QuizPop Quiz
1) Plants use carbon dioxide (____), water (____), and the1) Plants use carbon dioxide (____), water (____), and the
sun’s energy to make food.sun’s energy to make food.
COCO22 andandHH22OO
2) What type of cell has chloroplasts?2) What type of cell has chloroplasts?
PLANT CELLPLANT CELL
3) BOTH plants and animals must break down food in3) BOTH plants and animals must break down food in
order to get ________from it.order to get ________from it.
ENERGYENERGY
4) How are respiration and photosynthesis related?4) How are respiration and photosynthesis related?
THEY ARE THE REVERSE (OPPOSITE) OF EACHTHEY ARE THE REVERSE (OPPOSITE) OF EACH
OTHER.OTHER.
5) Fermentation is a way to get energy when ______ isn’t5) Fermentation is a way to get energy when ______ isn’t
available.available.
OXYGENOXYGEN

14. Today’s Learning GoalsToday’s Learning Goals
 In plants, chloroplasts captureIn plants, chloroplasts capture
energy from the sun in orderenergy from the sun in order
to make food duringto make food during
photosynthesisphotosynthesis
 Cells release energy from foodCells release energy from food
through either cellularthrough either cellular
respiration of fermentationrespiration of fermentation
 Why it matters: UnderstandingWhy it matters: Understanding
how plants & animals gethow plants & animals get
energy to grow & develop is anenergy to grow & develop is an
important part of biology.important part of biology.