[Intro: Heath Cottengim]
This is an educational video
If you don't have your notes in front of you you ain't ready for this
This is college level *scratch* right here

[Verse 1: Heath Cottengim]
Now I don't usually rap about plant life
But last night while I sat at a red light
I saw a tree just growing and you know I'm going
"Hey tree, how do you get your energy?"
I know it's photosynthesis I'm not that dumb
I'm asking what's the path that that energy comes from
I had to know so I drove home so fast
So I could lay down a beat about a chloroplast
The organelle with fat stacks of thylakoids
Where molecules of water go to get destroyed
By that I mean they’re oxidized at Photosystem II
A protein complex that uses light, to excite
A few electrons to a high energy state
They’ll be powering the proton pumps that will generate a
Gradient across the thylakoid membrane
Looks like we got ourselves another electron transport chain
Only this time, protons have been pumped inside
If they want to diffuse out, they’re gonna have to slide through ATP synthase, the only enzyme you know, that’s gonna make
ATP whenever there’s proton flow
How many? Well the Calvin Cycle uses
18 ATP for each glucose it produces
I have to warn you, things are about to get edgy
I’m about expose the secret life of veggie

[Chorus: Heath Cottengim]
Stealing light from the sun, that’s the motto
Whether you’re a bean or tomato. Grand theft autotrophs
Have got the growth phenomenon
Built on that famous sugary hexagon
Not to mention releasing oxygen gas
Promoting evolution and greater biomass
So throw your hands in the air, 'cause you know it wouldn't be there if it wasn’t for this: photosynthesis

[Interlude: Heath Cottengim]
Yo, let's change it up right here

[Verse 2: Heath Cottengim]
A lot has happened so far, but we’re not done 'cause our electron has arrived at Photosystem I
All the energy from that initial photon has been used up by this point and is now gone
One more round of photoexcitation is an indication that we’re back up to a high energy elevation
So the plant, or algae, or whatever wants to get these electrons out into the stoma
Which in case you’ve been living in a coma, is where the Calvin Cycle goes over and over
NADP+ is willing to gain, two electrons and an H in exchange for a name change to
NADPH, a stable coenzyme designed to provide a hydride when it’s time
And when it is, you’re gonna need 12 of those suckers
Why so many? Don’t look at me! I didn’t make the recipe!
Ha, just kidding, I’ll tell you the reason. But first: a thesis that I’ve been meaning to appease
Among these two molecules on our shopping list ATP hits biggest with 18 needed to assist
That kind of demand demands a better plan than having an electron span both photosystems man
Therefore, electron takes a detour before it gets absorbed by NADP+ and thus
Like a television, it's gonna rerun through the ETC and back to photosystem 1 when its done
In conclusion, ATP deficit? cyclic transport’s fixin’ it as long as the area’s well lit
Now we have the energy we need, invested chemically, so we can leave like a bird from the nest
'Cause up next, in the stroma, don’t be afraid
We’re gonna see how the biological sausage is made

[Chorus: Heath Cottengim]
Stealing light from the sun, that’s the motto
Whether you’re a bean or tomato. Grand theft autotrophs
Have got the growth phenomenon
Built on that famous sugary hexagon
Not to mention releasing oxygen gas
Promoting evolution and greater biomass
So throw your hands in the air, 'cause you know it wouldn't be there if it wasn’t for this: photosynthesis

[Interlude: Heath Cottengim]
Yo, we 'bout to begin the dark reactions so
Hit 'em with that next beat

[Verse 3: Heath Cottengim]
CO2 gets bound to RuBP to make a
6-carbon compound that’s about as stable as
Mike Tyson on ice skates, so it separates
Into 2 molecules of 3-phosphoglycerate
Don’t worry about RuBP, it’s just a structure pre-made to receive a CO2 upgrade
What you need to know is that this combo won’t go without an assist from a catalyst called Rubisco
Rubisco, this protein, has gotta be
The most important enzyme that you’ve ever seen
And you’ve definitely seen it, most abundant on the planet
Making good use of its fixation talent
Sliding carbons on the chain so smooth: Crisco
Put it on your Bio highlight reel: GoPro
“I don't think it’ll be on the test.” You wish bro
Forget this enzyme and I’ll throw you out the window
Back to 3-phosphoglycerate, which we abbreviate to 3PG
The strategy is ATP’ll donate a phosphate
While NADPH reduces, which produces
Breaking news it’s G3P, the three “C” MVP
This compound leaves the chloroplast so fast passed your retina
To make glucose, cellulose, starch, etcetera
If the Calvin Cycle ended here that would be pretty radical
But the actual, forces us to now get mathematical
If you ran the cycle three times, you might think you’d have
6 G3P ready to go, but no
Only one of those goes to make a sugar, the rest are gonna linger, what you need to consider are the
3RuBPs that were found initially will be absentee the next round, unless we rebound
Let me help you get the sense of what’s about to go down
5 G3Ps condense to-3-sequences-of 5
Keeping alive, the carbon end of the bargain, but we’re starving without the icing on the
Cake: a phosphate, three P's please
Don’t forget this is us paying the debt for-the-three
RuBP we spent at the cycle’s onset
Guys let’s try to summarize in under a minute
6 of Calvin’s cycles sights the arrival of the
2 G3Ps that are the keys to the puzzle to make
One glucose, which’ll cost us both a lot of
ATP and NADPH, specifically 18 and 12
Respectively, effectively the Calvin Cycle’s batteries
Hope your next test or project gets you good looks
I’m off to write another chapter in the hip-hop textbook

[Outro: Heath Cottengim]
Woo, yeah, no excuses now
You better not have forgot about Rubisco already
Shout out to your mom, Mother Nature
Don’t hate us 'cause we’re making that glucose, son...light
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