
After looking at your pictures…
› share what you’ve noticed about where
Carbon is found…
› Share what you’ve noticed about how
Carbon moves from place to place…

We are going to focus on some of the
natural processes that move Carbon…
› Photosynthesis
› Cellular Respiration
Using Bromothymol Blue is a pH indicator.
 Review:

› What is pH?
› How does the scale work?
BTB gets bluer the more basic a solution
is.
 When CO2 is in water, it forms Carbonic
Acid, H2CO3
 We will use BTB as an indicator of CO2


Purpose?
› Convert light energy into stored chemical
energy (=glucose) that the plant can use

Who does it?
› Autotrophs

Where does it happen?
› Choloroplasts

Chloroplasts
6CO2 + 12H20
C6H12O6 + 6O2 + 6H20
Note** water on product side is NEW, formed from
different combination of H’s and O’s.

Purpose
› Convert stored chemical energy into
useable energy (=ATP)

Who does it?
› ALL organisms (even plants!)

Where?
› Mitochondria
C6H12O6 + 6O2
6CO2 + 6H2O + Heat + ATP

Enzymes involved in both reactions (PS
&CR)
› Different enzymes = specificity
› Increase speed of chem rxns
› Lower activation energy (so cell won’t fry)

ATP= chemical energy used to do WORK
› Usable Energy stored in bonds (AT-P-P~P) that is
released when bonds are broken
› Used for movement & breakdown of molecules
› Comes from glucose breakdown!
› Energy not recycled, but nutrients and matter are
Go back to your Elodea / Fishy Models.
 Fix and add to your explanations.


Different types of plants “trap” CO2 for
photosynthesis in slightly different ways.

At Tucker Prairie, there is competition
between these C3 & C4 Plants
› C3 Plants trap CO2 with one enzyme
› C4 Plants trap CO2 with two enzymes and
require a little bit of extra energy
~85% of all plants are C3
 Examples—rice, wheat, barley, most
trees and many grasses

› Grasses of Tucker Prairie
Stomata are open during day and
closed at night—this is important
because they can get CO2 for
photosynthesis
 Do best in Temperate environments



~3% of all land plants
Examples—corn, sugarcane, and many grasses
› Forbs of Tucker Prairie

Stomata are open during day and closed at
night—BUT…stomata can close if the plant is
losing too much water during the day.
›
›

When stomata close, CO2 concentration in leaves
go down.
Plant can still do photosynthesis because of the 2nd
enzyme
Do well in tropical, high heat intensity and
drought conditions
C3 Pathway

Which plants have the advantage—
› C3 Grasses?
› C4 Forbs?