Situation: the autotrophs have produced sugar and oxygen.

Energy

6CO2 + 6H2O C6H12O6 + 6O2

Now – how do we RELEASE the energy in that sugar?

Need to turn the sugar into

ATP is the cell’s energy molecule

ATP

What Does ATP Do for What Does ATP Do for You?You?

It supplies YOU withIt supplies YOU with ENERGY!ENERGY!

How Do We Get Energy How Do We Get Energy From ATP?From ATP?

By breaking the last By breaking the last P – P bondP – P bond

PAdenine P P

Adenine P P P

How Does That How Does That Happen?Happen?

An An Enzyme!Enzyme!

When is ATP Made in When is ATP Made in the Body?the Body?

• During During cellular cellular respirationrespiration

• both plants & animals do both plants & animals do it!it!

Cellular Cellular Respiration:Respiration:

releasing the energy in food as releasing the energy in food as ATPATP

Question:Question:In what kinds organisms does In what kinds organisms does

cellular respiration take place?cellular respiration take place?

Cellular Respiration is the Cellular Respiration is the reverse of photosynthesisreverse of photosynthesis

C6H12O6 + 6O2 6CO2 + 6H2O+ energy ATP

What are the Stages of What are the Stages of Cellular Respiration?Cellular Respiration?

In cytoplasmIn cytoplasm

1. Glycolysis (sugar is split)1. Glycolysis (sugar is split)

In mitochondria:In mitochondria:

2. The Krebs Cycle (citric acid 2. The Krebs Cycle (citric acid cycle)cycle)

3. The Electron Transport Chain3. The Electron Transport Chain

Glycolysis

Krebs Cycle

ETC

Look at textbook pp 222 - Look at textbook pp 222 - 228228

Step 1: GlycolysisStep 1: Glycolysis

Glucose 2 pyruvic acid

C-C-C-C-C-C C-C-C + C-C-C

http://www.northland.cc.mn.us/biology/Biology1111/animations/glycolysis.html

MitochondriaMitochondria

OrganelleOrganelle where cellular respirationcellular respiration takes place.

Step 2: Kreb’s CycleStep 2: Kreb’s Cycle

C-C-C CO2 & a whole bunch of NADHs

http://www.science.smith.edu/departments/Biology/Bio231/krebs.html

Electron Transport ChainElectron Transport Chain

High energy electrons used to convert ADP to ATP

http://www.science.smith.edu/departments/Biology/Bio231/etc.html

Glycolysis

C-C-C-C-C-C

C-C-CKrebs Cycle

ETC

CO2 + NADH ATP + H2O

O2

CR: 36 NET ATP

Animation of CR:Animation of CR:qcc.cuny.edu/BiologicalSciences/Faculty/DMeyer/respiration.htmlqcc.cuny.edu/BiologicalSciences/Faculty/DMeyer/respiration.html

http://scholar.hw.ac.uk/site/biology/activity3.asphttp://scholar.hw.ac.uk/site/biology/activity3.asp

But what happens when But what happens when there is no oxygen present?there is no oxygen present?

Glycolysis

C-C-C-C-C-C

C-C-C

Krebs Cycle

ETC

Only Glycolysis can occurOnly Glycolysis can occurO2

FermentationFermentation

Occurs when OOccurs when O22 isis NOTNOT presentpresent

AKA AKA anaerobicanaerobic respiration respiration

Two types:Two types:

Lactic Acid Lactic Acid fermentationfermentation (muscle (muscle cells)cells)

Alcoholic Alcoholic fermentationfermentation (yeast)(yeast)

Nets onlyNets only 2 ATP 2 ATP (instead of 36)(instead of 36)

Lactic Acid Lactic Acid FermentationFermentation

Animals (pain in muscle after Animals (pain in muscle after workout)workout)

glucose

Glycolysis

CCCCCC

CCC

Pyruvic acid

CCC

Lactic AcidLactic Acid

Alcohol FermentationAlcohol Fermentation

Plants and FungiPlants and Fungi beer and beer and winewine

glucose

Glycolysis

CCCCCC

CCC

Pyruvic acid

CC

EthanolEthanol

Aerobic or Anaerobic Aerobic or Anaerobic RespirationRespiration

Question:Question:

Glucose (carbohydrate) is the main Glucose (carbohydrate) is the main source of food for making ATP from source of food for making ATP from cellular respiration. cellular respiration.

What other food molecules can be What other food molecules can be used in Cellular Respiration?used in Cellular Respiration?

Other organic molecules used for fuel:

1. Carbohydrates: polysaccharides

2. Fats: glycerols and fatty acids

3. Proteins: amino acids