Cell Energy and ATP - Mill Creek High School

ATP in a Molecule
Energy is needed for:
Active transport
Cell division
Movement of cilia and flagella
Production and storage of proteins
ATP – adenosine triphosphate
• Quick energy for any organelle in a cell
that needs it
• Energy is stored in the chemical bonds of
this molecule
• Made up of:
1. adenosine molecule (adenine +
2. 3 phosphate groups
Figure 6.8 The structure and hydrolysis of ATP
• ATP is a nucleotide that performs many
essential roles in the cell.
• It is the major energy currency of the cell,
providing the energy for most of the
energy-consuming activities of the cell.
• It is one of the monomers used in the
synthesis of RNA and, after conversion to
deoxyATP (dATP), DNA.
• It regulates many biochemical pathways.
• When the third phosphate group of ATP is
removed by hydrolysis, a substantial
amount of free energy is released.
• ATP + H2O  ADP + Pi
• ADP is adenosine diphosphate. Pi is
inorganic phosphate.
• For this reason, this bond is known as a
"high-energy" bond and is depicted in the
figure by a wavy red line.
Dehydration synthesis hooks new
phosphates on (takes energy to make bond)
Hydrolysis removes ONE Phosphate and
releases energy
Pg 101
How do cells use the energy of
• ATP is a small compound
• Cellular proteins have a specific site where ATP
can bind; thus, when the last bond in ATP is
broken and the energy is released, the cell can
use the energy
Ex. Active transport, making proteins,
• ATP is like a battery – it represents stored
energy, and must “fit” into correct area to
access that energy
2 major processes that deal with
the use/production of ATP:
• Photosynthesis –
conversion of light energy to chemical
energy (sugar); this sugar can then be
used through the process of
• Cellular respiration –
breakdown of sugar to produce ATP
(~38 ATP produced per glucose)
The equations…
• Photosynthesis: (in chloroplasts)
6H20 + 6CO2 + 38 ATP C6H12O6 + 6O2
• Cellular respiration: (in mitochondria)
C6H12O6 + 6O2 + 38 ADP + 38Pi 
6CO2 + 6H20 + 38ATP
Types of reactions based on
energy transformations…
• In any chemical reaction, bonds are either
formed or broken.
• Since bonds are a form of energy, all
reactions result in either the absorption or
release of energy.
• Exergonic reactions are ones that
release energy; here, bonds are broken –
cellular respiration is this!
• Endergonic reactions absorb energy to
form bonds – photosynthesis is this!

similar documents