Bell-Ringer1) What is the first step of Cellular Respiration?

a) Aerobic Respirationb) Krebs Cyclec) Glycolysisd) Glucose

2) ATP is formed during glycolysis when…a) the cell breaks the glucose molecule in halfb) the cell removes phosphate groups from the sugar moleculesc) the cell adds phosphate groups to the G3P

Bell-Ringer3) Draw a G3P molecule with two phosphate

groups attached (hint: this is the step right before ATP is made)

4) How are photosynthesis and cellular respiration related?a) Both create sugar moleculesb) Both create ATPc) They are the same equations, just backwardd) They are not related

More Inside the Blue Monster...

[Krebs Cycle Review]

Review• At the end of glycolysis, glucose has been

changed into two 3-carbon chains and the cell has a net gain of two ATP.

Cellular Respiration• After glycolysis, the two 3-carbon chains start

the process of aerobic respiration (the second half of cellular respiration.)

Cellular Respiration• After glycolysis, the two 3-carbon chains start

the process of aerobic respiration (the second half of cellular respiration.)

• Aerobic respiration is made up of two distinct steps:1) The Krebs Cycle2) The Electron Transport Chain

Cellular Respiration• After glycolysis, the two 3-carbon chains start

the process of aerobic respiration (the second half of cellular respiration.)

• Aerobic respiration is made up of two distinct steps:1) The Krebs Cycle2) The Electron Transport Chain

Today, we are going to follow the Blue Monster’s food through the Krebs Cycle

Krebs Cycle• The Krebs cycle begins with one of the 3-

carbon molecules left over from glycolysis.

Krebs Cycle• Before the Krebs cycle can begin, the 3-carbon

molecule moves into the cell’s mitochondria. • All steps of the Krebs Cycle occur within this

organelle.

Krebs Cycle• The Krebs Cycle also occurs in 4 steps.

Krebs Cycle• Before the Krebs Cycle begins, the 3-carbon

molecule from glycolysis has one carbon removed.

• The new, 2-carbon molecule is referred to as Acetyl CoA.

Krebs Cycle1) The 2-carbon Acetyl CoA molecule combines

with an Oxaloacetic Acid molecule to become a 6-carbon sugar molecule.

• The 6-carbon molecule is known as Citric Acid

Krebs Cycle2) Citric Acid loses a CO2 molecule, creating a

new 5-carbon molecule.

Krebs Cycle2) Citric Acid looses a CO2 molecule, creating a

new 5-carbon molecule. • This CO2 molecule is a waste product that

exits the blue monster as he breathes out.

Krebs Cycle3) The 5-carbon sugar loses another CO2.

• An ATP molecule is formed from the energy in this broken bond.

Krebs Cycle3) The 5-carbon sugar loses another CO2.

• An ATP molecule is formed from the energy in this broken bond.

ATP Gain for Krebs Cycle:

Krebs Cycle3) The 5-carbon sugar loses another CO2.

• An ATP molecule is formed from the energy in this broken bond.

ATP Gain for Krebs Cycle:1 ATP

Krebs Cycle4) The 4-carbon sugar is reformatted into an

Oxaloacetic Acid.

Krebs Cycle4) The 4-carbon sugar is reformatted into an

Oxaloacetic Acid. • This oxaloacetic acid molecule comes back

into the Krebs cycle at step one to create another 6-carbon molecule.

Krebs CycleThe Krebs cycle moves in a circle, each time

recreating the compounds needed for the cycle to continue.

• Tomorrow:

The Electron Transport Chain

Inside the Monster Illustrations

• Illustrate Glycolysis on the front

• Krebs on the back• Add color!

Exit Slip1) Which answer below lists the steps of Cellular

Respiration in the correct order?a)Glycolysis, Electron Transport Chain, Krebs Cycleb) Electron Transport Chain, Krebs Cycle, Glycolysisc) Krebs Cycle, Glycolysis, Electron Transport Chaind) Glycolysis, Krebs Cycle, Electron Transport Chain

2) What must occur before the Krebs cycle can start?a) G3P is turned into a glucose moleculeb) G3P is turned into Acetyl CoAc) G3P has the phosphates removedd) G3P is turned into Oxaloacetic Acid

3) We know the Krebs Cycle is occurring within our bodies because…a) We have glucose in our blood streamb) We breathe out CO2, a by-product of Krebsc) We breathe in O2, needed to start Krebsd) We breathe out CO, a by-product of Krebs

4) What is the net ATP gain for Glycolysis and the Krebs Cycle?

a) 2b) -2c) 3d) 4