Do Now – On paper to turn in (Q & A)

• 1. What gas do you inhale? Exhale?• 2. What transports oxygen to your cells?• 3. Why do your cells need oxygen?• 4. What molecule acts as energy for your

cells? What process produces this molecule?

• 5. What cells in your body might need to do more cellular respiration than others?

LAB: Exercise and Respiration

• PS: What is the effect of…• Hypothesis: In an “If…,then…” statement• Procedures: Briefly describe your

experiment• Variables: Identify IV, DV, control,

constants• Data: Record your data in a table

Individual assignment

• GRAPH your data• Write a CONCLUSION in C – E – R

format.– CLAIM: What did your experiment show?– EVIDENCE: Describe your data/– REASONING: Give a SCIENTIFIC

EXPLANATION for your results. Think about WHY cells would produce more carbon dioxide?

Cellular Respiration

ATP-ADP cycle

Food is energy

• Food is chemical energy • Photosynthesis stores radiant energy

from the sun in the bonds in organic molecules.

Releasing chemical energy

• Cellular respiration – chemical reaction that uses oxygen to convert chemical energy in organic molecules into adenosine triphosphate (ATP)

• About 40% of food consumed is used

ATP!

ATP stores energy

• ATP – adenosine triphosphate– 1 adenine (nitrogen containing compound)– 1 sugar– 1 3-phosphate tail (ENERGY!)

The triphosphate tail• The triphosphate in

ATP stores the energy

• Each phosphate is negative; repulsion stores PE

• When phosphate bond is broken, PE is released

What are you left with?

The ATP cycle• When ATP loses a

phosphate it becomes ADP

• ADP is recyclable• Adding a phosphate

(phosphorylation) to ADP requires energy

• where do we get this energy from?

Cellular Respiration

C6H12O6 + 6O2 6CO2 + 6H2O + 36ATP

Glucose + oxygen carbon + water + cell dioxide

energy

Structure of the mitochondria

• Site of majority of respiration

• Highly folded to increase surface area

Cellular Respiration contains 3 steps

Step 1: Glycolysis

• Requires 2 ATP to split 1 glucose creating 2 pyruvic acid molecules

• Creates 4 ATPs

Glycolysis Summary

• _______ ATP are used to produce _______ ATP, for a net gain of ______ ATPs

• 1 molecule of glucose has been converted into 2 molecules of ________________

Step 2: The Krebs Cycle

• Pyruvic acid diffuses into the mitochondria matrix

• Before the Krebs cycle PA is converted into acetyl CoA– By loss of a CO2

Step 2: The Krebs Cycle

• Acetyl CoA joins oxaloacetate creating citric acid

• CO2 is released • 1 ATP produced• Forms several NADHs

Step 2: The Krebs Cycle

• oxaloacetate is left over and grabs the other pyruvic acid and does it again

• NADHs continue to step 3

The Krebs Cycle Summary

• Glucose molecule has been completely broken down

• ______ gas and _________ ATP are produced– ______ ATP per turn

• NADHs have been created storing ___________

Step 3: Electron Transport

• NADH transfers electrons to electron transport chain in the inner membrane

• Electrons move from carrier to carrier, eventually being pulled to the electron grabber, OXYGEN– The oxygen, electrons, and H+ ions bond to

make water (a product)

Step 3: Electron Transport

• Each transfer of electrons releases energy that is used to make ATP

• This energy is used to make 32 ATP!

Adding it all up!

• For every glucose molecule, your cells make up to ________ ATP!

• Glycolysis is the only step that does not require oxygen

ATP without oxygen?

• What happens if you cannot take in oxygen fast enough to meet your ATP demand?

ACTIVITY: Create a two-column chart comparing cellular respiration and fermentation