1

Objective: Outline what enters

and leaves each step of

cellular respiration.

YOUR CELLS GET ENERGY THROUGH 4 STEPS:

#1 GLYCOLYSIS: GLUCOSE IS CONVERTED INTO PYRUVIC ACID.

#2 PYRUVIC ACID CONVERTED INTO ACETYL-COA.

#3 ACETYL-COA ENTERS THE CITRIC ACID CYCLE. NADH and FADH2 (BUS) LEAVES THE CITRIC ACID CYCLE.

#4 NADH ENTERS ELECTRON TRANSPORT CHAIN. ATP (ENERGY) LEAVES THE ELECTRON TRANSPORT CHAIN.

2

•GLYCOLYSIS CAN OCCUR WITH OR WITHOUT OXYGEN.

•GOAL: GLUCOSE HAS TO GET TO THE MITOCHONDRIA BUT IS NOT ALLOWED. THEREFOR GLUCOSE “CHANGES” ITSELF INTO PYRUVIC ACID SO THAT IT CAN NOW ENTER THE MITOCHONDRIA.

MY NAME IS

GLUCOSE. I AM

SAD THAT I CAN

NOT GET INTO THE

MITOCHONDRIA.

BUT I CAN GET

INTO THE

MITOCHONDRIA

DISGUISED AS

PYRUVIC ACID.

3

•IN THIS STEP, PYRUVIC ACID TRAVELS INTO THE MITOCHONDRIA, WHERE THE CITRIC ACID CYCLE TAKES PLACE.

•HOWEVER, OUR HERO PYRUVIC ACID (THE ARTIST FORMERLY KNOWN AS GLUCOSE) HAS TO “CHANGE”AGAIN IN ORDER TO ENTER THE CITRIC ACID CYCLE.

•PYRUVIC ACID CHANGES INTO ACETYL-CoA.

4

PYRUVIC ACID ACETYL CO-A

•CITRIC ACID CYCLE TAKES PLACE IN THE LIQUID INTERIOR OF THE MITOCHONDRIA (STROMA) AND REQUIRES THE PRESENCE OF OXYGEN.

• ACETYL-COA ENTERS THE CITRIC ACID CYCLE.

•3 NADH BUSES AND 1 ATP LEAVE THE CITRIC ACID CYCLE.

5

ACETYL-COA

6-CARBON

MOLECULE

5-CARBON

MOLECULE4-CARBON

MOLECULE

DIFFERENT

4-CARBON

MOLECULE

BUS

CO2

CO2, ATP, AND BUS

2

BUSES

6

7

•TAKES PLACE ALONG THE INNER MEMBRANE OF THE MITOCHONDRIA

•PURPOSE OF THIS STEP IS SIMPLE: THE BUSES DROP OFF THE ELECTRONS AT THE ELECTRON TRANPORT CHAIN WHERE THEY ARE USED TO MAKE ATP (ENERGY).

ELECTRON

TRANSPORT

CHAIN

8

9

10

Movie

• VCAC: Cellular Processes: Electron

Transport Chain: The Movie