ATP - TeacherWeb

AP Biology
The energy needs of life
ƒ Organisms are _______________ systems
Making energy!
‹
What do we need energy for?
ƒ ________________________
Š building biomolecules
ƒ ________________________
ƒ ________________________
ƒ ________________________
ƒ ________________________
ATP
The point
is to make
ATP!
AP Biology
2007-2008
Where do we get the energy from?
ƒ Work of life is done by _________________
‹
use ____________ (catabolic) reactions to
fuel ____________ (anabolic) reactions
AP Biology
Living economy
ƒ Fueling the body’s economy
‹
eat high energy _______________________
‹
break them down
‹
capture
t
released
l
d energy in
i a form
f
the
th cell
ll can use
ƒ food = carbohydrates, lipids, proteins, nucleic acids
ƒ digest = catabolism
synthesis
y
+
+
energy
ƒ Need an energy currency
‹
synthesis
+
AP Biology
+
a way to pass energy around
Whoa!
Hot stuff!
energy
ATP
AP Biology
1
AP Biology
ATP
ƒ __________________________
‹
How does ATP store energy?
modified nucleotide
–O
ƒ nucleotide =
adenine + ribose + Pi → _______
ATP
ƒ AMP + Pi → _______
ƒ ADP + Pi → _______
‹
a lot of stored energy in each bond
‹
ƒ most energy stored in 3rd Pi
ƒ 3rd Pi is hardest group to keep bonded to molecule
high energy bonds
ƒ Bonding of negative Pi groups is unstable
spring-loaded
Pi groups “pop” off easily & release energy
‹
‹
AP Biology
AP Biology
Instability of its P bonds makes ATP an excellent energy donor
How does ATP transfer energy?
–O
ADP
O– O–
P –O
O– P O–
O O
–O
O–
P O– +
O
An example of Phosphorylation…
ƒ Building polymers from monomers
7.3
energy
ƒ ATP → ADP
‹
releases energy
‹
can fuel other reactions
ƒ ∆G = -7.3 kcal/mole
ƒ Phosphorylation
‹
released Pi can transfer to other molecules
ƒ destabilizing the other molecules
‹
AP Biology
O– O– O–
P –O
O– P –O
O– P O–
O O O
ƒ Each negative PO4 more difficult to add
adding phosphates is endergonic
How efficient!
Build once,
use many ways
I think
he’s a bit
unstable…
don’t you?
enzyme that phosphorylates = ______________
‹
‹
need to destabilize the monomers
phosphorylate!
H
C
OH
+
C C
O
+ ATP
H
AP Biology
H H
C
HO
+4.2 kcal/mol
“kinase”
H
C
OH
C
H
+
P
enzyme
-7.3 kcal/mol
H
C
P
H
H H
C
HO
C C
O
-3.1 kcal/mol
H H
C C
OHHO
enzyme
+
+
H2O
ADP
+
Pi
2
AP Biology
Another example of Phosphorylation…
ATP / ADP cycle
ƒ The first steps of cellular respiration
‹
Can’t store ATP
beginning the breakdown of glucose to make ATP
Those
phosphates
sure make it
uncomfortable
around here!
glucose
C-C-C-C-C-C
hexokinase
phosphofructokinase
2 ATP
C
C
2 ADP
DHAP
P-C-C-C
G3P
C-C-C-P
P
synth
esis
Cells spend a lot of time making ATP!
The
point is to make
ATP!
H
C
fructose-1,6bP
P-C-C-C-C-C-C-P
AP Biology
9 too reactive
9 transfers Pi too easily
9 only short term energy
storage
ƒ carbohydrates & fats are
long term energy storage
P
ATP
ƒ good energy donor,
cellular
not good energy storage respiration
7.3
kcal/mole
ADP + P
A working muscle recycles over
10 million ATPs per second
Whoa!
Pass me
the glucose
(and O2)!
AP Biology
H+
_________________
H+
ƒ Enzyme channel in
H+
H+
H+
H+
H+
H+
rotor
mitochondrial membrane
‹
‹
permeable to H+
____________________
____________________
rod
ƒ flow like water over
water wheel
What’s the
point?
ƒ flowing H+ cause
change in shape of
ATP synthase enzyme
ƒ powers bonding of
Pi to ADP:
ATP
__________________
AP Biology
APBut…
Biology How
catalytic
head
ADP + Pi
H+
is the proton (H+) gradient formed?
3
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That’s the rest
of my story!
Any Questions?
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