DO Now

• What is the photosynthesis formula?

• 1. What are the stages of cellular respiration?• 2. What are the difference between aerobic

and anaerobic respiration?

Energy needs of life• Animals need energy for…

• synthesis (building for growth)• reproduction• active transport• movement• temperature control (making heat)

Where do we get energy?• Energy is stored in organic molecules

– carbohydrates, fats, proteins• Animals eat these organic molecules food

– digest food to get• fuels for energy (ATP)• raw materials for building more molecules

– carbohydrates, fats, proteins, nucleic acids

ATP

2009-2010

ATP

What is energy in biology?

Whoa! HOT stuff!

Adenosine TriPhosphate

Releasing the Energy (Break the Bond)

• Break into ADP and P to release energy!

• ADP—adenosine diphosphate

ATP

Harvesting energy stored in food• Cellular respiration: the process of

breaking down food to produce ATP• in mitochondria• using oxygen

– “aerobic” respiration

– usually digesting glucose• but could be other sugars,

fats, or proteins

C6H12O6 6O2 ATP 6CO2 6H2O+ + +

glucose + oxygen energy + carbon + water dioxide

O2

food ATP

What do we need to make energy?• The “Furnace” for making energy

– mitochondria • Fuel

– food: carbohydrates, fats, proteins• Helpers

– oxygen– enzymes

• Product– ATP

• Waste products– carbon dioxide

• then used by plants

– water

O2

food

ATP

Make ATP!Make ATP!All I do all day…And no oneeven notices!

enzymes

CO2 H2O

Mitochondria are everywhere!!animal cells plant cells

Can’t store ATP too unstable only used in cell

that produces it only short term

energy storagecarbohydrates & fats

are long term energy storage

How do we use ATP to do work?

A working muscle recycles over 10 million ATPs per second

ATP

ADP

work

Whoa! Pass me theglucose & oxygen!

Adenosine DiPhosphate

Adenosine TriPhosphate

The Steps of Respiration• 1. Glycolysis (no oxygen required)• 2. Kreb’s Cycle (oxygen required)• 3. Electron Transport Chain (oxygen required)

Glycolysis

• Convert glucose pyruvate• Occurs in the cytoplasm• Produces 2 net ATP

Kreb’s Cycle

• Occurs in the mitochondria

• Produces CO2

• Produces 2 net per cycle

ATP

Do Now• What are the reactants and

products of respiration?

Electron Transport Chain (ETC)

• Occurs in the mitochondria (inner membrane)• requires OXYGEN• Produces 32 net ATP

ETC• ATP Synthase: enzyme that

produces (from ADP + P) when protons pass through (passive transport)

• Proton gradient allows this to occur—as electrons travel down the ETC, protons are forced into the intermembrane space (active transport)

• OXYGEN is the final electron acceptor—produces H2O

ATP

ATP

How much energy are we talking?

Cellular respiration produces a net total of 36 !

Glycolysis 2

Kreb’s Cycle 2

ETC 32

Total 36

ATP

ATP

ATP

ATP

ATP

What if oxygen is missing?• No oxygen available = can’t complete

aerobic respiration• Anaerobic respiration

– also known as fermentation• alcohol fermentation• lactic acid fermentation

– no oxygen or no mitochondria (bacteria)

– can only make very little ATP– large animals cannot survive

O2

yeast

bacteria

Anaerobic Respiration• Fermentation

– alcohol fermentation• yeast

– glucose ATP + CO2+ alcohol

– make beer, wine, bread

– lactic acid fermentation• bacteria, animals

– glucose ATP + lactic acid– bacteria make yogurt– animals feel muscle fatigue

O2

Tastes good…but not enoughenergy for me!

Do NowWrite down the stages of cellular respiration and the amount of produced at each stage

Glycolysis 2

Kreb’s Cycle 2

ETC 32

Total 36

ATP

ATP

ATP

ATP

ATP

Aerobic v. Anaerobic Respiration

Balloon and Yeast Demo

• Fact: Yeast undergo respiration

• PREDIT: What will happen to the balloon when I mix yeast and sugar in warm water?

• ANALYZE: • 1. Why did the balloon swell

up?• 2. Why did I add sugar to the

yeast?

What happens when we DON’T have O2??

ANAEROBIC RESPIRATION!!!

Definition: a form of Cellular Respiration that occurs when O2 is absent or scarce. A.k.a. fermentation

Fermentation allows glycolysis to continue

Note: Fermentation itself does not produce ATP—it allows glycolysis to continue, which produces 2 ATP

Anaerobic Respiration: WHERE does it occur?

Anaerobic Respiration: 2 VersionsLactic Acid Fermentation

• Produces…– Lactic acid (C3H6O3)

• Occurs during high-intensity exercise

• Occurs in your muscle cells

• Also in bacteria and fungi

Alcohol Fermentation

• Produces…– Ethanol– CO2

• CO2 accounts for the carbonation (the bubbles!)

• Occurs in yeast and in bacteria

Lactic Acid Fermentation

Let's hear from the Dr.’s

Alcohol Fermentation

Other effects of fermentation

STOP AND THINK• Why do you use yeast to make bread dough

rise?

• Why does it make sense that bacteria in your digestive tract undergo fermentation?

Guess Who?: Fermentation Edition

Guess Who??

• 1. occurs in this organelle:

• 2. can occur in the absence of O2

Guess Who??

• 3. occurs here:

• 4. produces CO2 as a product• 5. produces ~36 ATP

Guess Who??

• 6. Accounts for the burn you feel in your muscles when you exercise

• 7. Can make beer• 8. Involves the ETC• 9. Is much less energy-efficient• 10. O2 is the final electron acceptor

• 11. Allows glycolysis to continue.

Group Activity (~10 minutes)

• Create a concept map in your groups using the notecards provided! Fill in yourself the appropriate # of ATP molecules.

Glucose

Glycolysis(cytosol)

O2 Present

Aerobic Respiration

~36 ATP CO2

No O2 Present

Lactic Acid Fermentation

2 ATP Lactic acid

Alcohol Fermentation

2 ATP Ethanol CO2

Exit Slip

• How do we differentiate between Aerobic and Anaerobic Respiration? Provide at least 3 reasons.