Download The Point is to Make ATP! Making energy!

Making energy!
ATP
The Point is to Make ATP!
AP Biology
2005-2006
Energy needs of life
 Organisms are endergonic systems

What do we need energy for?





AP Biology
synthesis (biomolecules)
reproduction
active transport
movement
temperature regulation
2005-2006
Where do we get the energy from?
 Work of life is done by energy coupling

use exergonic (catabolic) reactions to
fuel endergonic (anabolic) reactions
+
+
AP Biology
+
+
energy
energy
2005-2006
Living economy
 Fueling the economy



eat high energy organic molecules (food)
break them down = catabolism (digest)
capture energy in form cell can use
 Need an energy currency

a way to pass energy around
Whoa!
Hot stuff!
AP Biology
ATP
2005-2006
ATP
 Adenosine Triphosphate

modified nucleotide
 adenine + ribose + Pi → AMP
 AMP + Pi → ADP
 ADP + Pi → ATP
How efficient!
Build once,
use many ways
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an RNA
nucleotide
2005-2006
Why does ATP store energy?
O– O– O– O– O–
–O P –O
O– P –O
O––P
OO
P––O
O– P O–
O O O O O
I think he’s
a bit
unstable…
don’t you?
 Each Pi group more difficult to add

a lot of stored energy in each bond
 most stored in 3rd Pi
 ∆G = -7.3 kcal/mole
 Close packing of
negative Pi groups

spring-loaded
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instability
of its P bonds makes ATP an excellent energy donor
2005-2006
How does ATP transfer energy?
O– O– O–
–O P –O
O– P –O
O– P O–
O O O
O–
–O P O– +
O
 Phosphorylation

when ATP does work, it transfers
its 3rd Pi to other molecules
 ATP → ADP
 releases energy
energy
Why is 3rd
phosphate
like a baaad
boyfriend?
 ∆G = -7.3 kcal/mole
 it destabilizes the other molecule
AP Biology
2005-2006
An example of Phosphorylation…
 Building polymers from monomers

need ATP for energy & to take the water out
H
C
OH
it’s never
that simple!OH
AP Biology
C
OH
C C
O
+ ATP
H
C
H H
+4.2 kcal/mol
“kinase”
H
C
+
H
+
P
enzyme
-7.3 kcal/mol
H
C
P
H
H H
C
OH
C C
O
-3.1 kcal/mol
+
+
H2O
ADP
+
2005-2006
Pi
Another example of Phosphorylation…
 The first steps of cellular respiration

beginning the breakdown of glucose → ATP
glucose
C-C-C-C-C-C
enzyme 1
those
phosphates
sure make it
uncomfortable
around here
enzyme 2
fructose-6P
P-C-C-C-C-C-C-P
enzyme 3
enzyme 5
DHAP
P-C-C-C
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2 ATP
2 ADP
enzyme 4
PGAL
C-C-C-P
enzyme 6
2005-2006
ATP / ADP cycle
Can’t store ATP
 too reactive
 transfers Pi too
easily
 only short term
energy storage
 carbs & fats are
long term energy
storage
Whoa!
Pass me the
glucose & oxygen!
AP Biology
A working muscle recycles over
10 million ATPs per second
2005-2006
What’s the point?
 Cells spend a lot of time making ATP!
“The point is to make ATP!”
Make ATP!
That’s all I
do all day.
And no one
even notices!
AP Biology
I didn’t
HEAR you!
2005-2006
Any Questions??
AP Biology
2005-2006