Once Upon a Time in the village of Greenville, Poppy and Flora were grabbing a bite to eat at their favorite restaurant, The Sunlight Bar and Grill. Flora didn't understand how they got all the nutrients they needed and asked her grandfather to explain it.

"Pops, can you explain how we get energy and process our food?"

"Of course! We use photosynthesis to take the energy from sunlight and make sugars and it takes place in our chloroplast"

Light

Energy

CO2

Sugars

O2

Water

C6H12O6 + 6O2

Products

Reactants

------>

6CO2 + 6H2O + sunlight energy

"First let's start with light reactions, they capture energy from sunlight and water is broken down while oxygen is being released. It all takes place in our thylakoid disks. NADPH and ATP are formed and are used to make sugars in the Calvin Cycle."

Now that Flora understood the light cycle it was time she learned about the Calvin Cycle.

"I get it now, we take in all the carbon dioxide and release the oxygen for the humans to breathe. But who's Calvin and why does he have his own cycle?"

Calvin

Cycle

3 CO2

rubisco

6 3-PGA

2 G3P

5 G3P

3 ATP

6 NADP+

3 ADP

6 ATP

6 ADP

6 NADPH

After explaining that Calvin wasn't a person it was time to explain the next part of the process.

"The Calvin Cycle takes place in our stroma and there are 4 main steps to the Calvin Cycle: carbon fixation, reduction phase, carbohydrate formation, and the regeneration phase. The ATP converts into ADP, the NADPH gets converted into NADP+ using energy, and the ADP combines with a phosphate. In Carbon Fixation, CO2 binds to RuBP sugars to help form Rubisco and then 6-carbon molecule splits into 2 3-carbon molecules."

"That must be the 3-PGA circles we saw in class! I think I know what happens next, In phase 2 the 3-PGA gets turned into G3P!"

That's right Flora!

Ohhh...

Flora was finally starting to get the hang it as Poppy finished explaining the Calvin Cycle.

"That's right Flora! Then they move to stage 3 where the energy from our light reactants mixes with the G3P and it turns into carbohydrates. Then as we move to stage 4 ATP mixes with G3P to make RuBP which goes back into the top of the cycle and it starts over again."

"Ohh I get it now Pops, the main purpose of the Calvin Cycle is to take the products from the light reactions of photosynthesis and make the stuff us plants need like water and glucose!"

electrons

via NADH

citric

acid

cycle

electrons via

NADH and

FADH2

Oxidative phosphorylation electron transport and chemiosmosis

glycolysis

pyruvate oxidation acetyl CoA

pyruvate

glucose

34 ATP

2 ATP

2 ATP

cytosol

mitochondria

Now that FLora understood the calvin Cycle it was time Poppy explained the next major part, Cellular Respiration.

"Cellular respiration releases chemical energy from sugars and other molecules to make ATP in the mitochondria. The formula is

C6H12O6 + 6O2 ---> 6Co2 + 6H2O + ATP."



"Oh I get it Pops! But what's the big deal about glycolysis? Rose said it takes 10 steps to find it."

"That's very good, but I think Rose was talking about glycolysis, a part of cellular respiration that has 10 long steps."

Products

Reactants

Glycolysis

3 Carbon Molecule

Glucose

3 Carbon Molecule

ATP

ATP

Kreb's Cycle

Acetyl CoA

CO2

ATP

NADH

FADH2