CELL ENERGY

CELL ENERGY

Photosynthesis &

Cellular Respiration

(Chapter 5)

PHOTOSYNTHESISis converting light energy into chemical energy (= carbs = FOOD).– Done by PLANTS

Things that can make their own food are called “AUTOTROPHS”. Auto- = self - troph = feeding– Autotrophs are “self-feeding:” mostly plants,

also cyanobacteria (green bacteria), & some protists (like algae & plankton)

Photosynthesis in PlantsPhotosynthesis is made possible by the green chlorophyll pigments found within chloroplasts in plants.

Chlorophyll a & b can ABSORB the energy from most wavelengths of light (but they reflect green & yellow light).

(There are other pigments [carotenoids] that absorb different wavelengths of light. You see these in Fall leaves).

Pigment Graphs

Inside each Chloroplast

There are structures that look like “stacks of coins”. These are THYLAKOIDS, and the chlorophyll is actually in them.

Gases (O2, CO2)

enter or exit

leaves through

holes called

“stomata”

Sugars go to

storage (as

simple sugars

in fruits, starches

in tubers, etc.)

Photosynthesis ChemistryBasic formula (*know this!):

CO2 + H2O -light-> C6H12O6 + O2

“Carbon dioxide and water, in the presence of light, produce glucose and oxygen.”

____ = Carbon dioxide _______ = glucose

____ = water __ = Oxygen

The balanced equation is:

___CO2 + ___H2O -light-> __C6H12O6 + ___O2

Photosynthesis ChemistryBasic formula (*know this!):

CO2 + H2O -light-> C6H12O6 + O2

“Carbon dioxide and water, in the presence of light, produce glucose and oxygen.”

CO2 = Carbon dioxide C6H12O6 = glucose

H2O = water O2 = Oxygen


6 CO2 + 6 H2O -light-> C6H12O6 + 6 O2

Just be glad I’m not asking you to memorize each step!

PHOTOSYNTHESIS happens in the CHLOROPLASTS of

PLANTS

THE REST happens in the MITOCHONDRIA of PLANTS

and of ANIMALS that eat plants.(happens in ALL eukaryotes, really)

CELLULAR RESPIRATIONIs using energy from food to make ATP, which gives cells the energy needed to live

(= metabolism).

Plants make the food (glucose) during photosynthesis, and they use some of it to fuel their own lives (they are autotrophs).

Animals cannot make their own food, and must eat plants to get it (or eat animals that ate plants)

Animals are heterotrophs

(“hetero” means “mixed”, “troph” = feeding)

2 Main TYPES of Cell. Resp.AEROBIC = “needing oxygen”– More efficient than anaerobic– Produces more ATP than anaerobic

• (makes a gain of 36 ATP overall)

ANAEROBIC = “without oxygen”Less efficient (produces only 2 ATP)Done by muscles that run out of oxygen

= LACTIC ACID FERMENTATION” = muscle soreness

– Done by yeast = “ALCOHOLIC FERMENTATION”

In the Mitochondria

There are 2 membranes, and the inner one has lots of folds (= more surface area for cellular respiration to happen).

Cellular Respiration Chemistry

Basic formula (*know this!):

C6H12O6 + O2 -enzymes-> CO2 + H2O+ energy

“Glucose and oxygen, in the presence of enzymes, produce carbon dioxide, water, and energy (ATP).”

Remember:




__C6H12O6 + ___O2 -enzymes-> ___CO2 + ___H2O + energy

Cellular Respiration Chemistry

Basic formula (*know this!):

C6H12O6 + O2 -enzymes-> CO2 + H2O+ energy(ATP)

“Glucose and oxygen, in the presence of enzymes, produce carbon dioxide, water, and energy (ATP).”

Remember:




C6H12O6 + 6 O2 -enzymes-> 6 CO2 + 6 H2O + energy(ATP)

Again, it could be worse!

The whole process:

So basically, it’s all a big energy cycle.

What photosynthesis makesis used in cellular respiration,

&What cellular respiration makes

is used by photosynthesis!

Another overview:

Image creditshttp://vincentimbe.files.wordpress.com/2007/11/krebs-cycle.jpgwww.funsci.comhttp://www.grow-a-head.com/index/images/stories/photosynthesis.jpghttp://www.zeraim.com/imagesEng/article18-04.jpghttp://www.cartage.org.lb/en/themes/sciences/zoology/AnimalPhysiology/Anatomy/AnimalCellStructure/Mitochondria/mitochondria.jpghttp://media.wiley.com/Lux/45/8545.nfg001.jpg

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CELL ENERGY