CELLS—Structure and Function
Role of ATP
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Phosphate
group (P)
P
H
N
P
P
H
N
(ATP is found
inside body cells)
O
O
O
N
P
O
O
O
P
O
O
P
O
H
O
Adenosine (A)
HO
OH
A
Ribose
sugar
Adenosine
Triphosphate
(ATP)
$$$$
N
Adenine
base
CH 2
O
covalent bond
to be broken
Investment
Analogy
N
H
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ATP hydrolysis is like a good investment. Though it requires an initial investment, it will be worth it because a good stock will return
more money in its dividend. Similarly, an initial investment of energy is required to break the covalent bond in ATP, but it's also worth
the initial investment of energy because the amount of energy released upon formation of the new bonds in the products is greater
than the inital investment. In summary, there is a net release of energy in ATP hydrolysis.
ATP
hydrolysis
equation:
ATPase
ATP
+
H2O
(Adenosine
triphosphate)
(plus)
(water)
(and ATPase
enzyme forms)
ADP
+
(Adenosine
diphosphate)
(plus)
Pi
+
(inorganic (plus)
phosphate
ion)
free
energy
(free energy)
(OR)
P
P
bond to
be broken
with the
help of the
ATPase enzyme
P
A
+
H
O
H
ATPase
H
P
P
A
+
P
O
+
H +
free
energy
can be used for any activity
the cell needs to perform.
For example:
● contraction of a
muscle cell
● active transport of
a substance across a
plasma membrane
● movement of cilia
● movement of a sperm
cell's tail
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