Transcript 4.1 Chemical Energy and ATP

4.1 Chemical Energy and ATP
KEY CONCEPT
All cells need chemical energy.
4.1 Chemical Energy and ATP
The chemical energy used for most cell processes is
carried by ATP.
• How do we get the energy we need?
• Food. Is it actually the food that energized us?
• Molecules in food store chemical energy in their bonds.
Starch molecule
Glucose molecule
4.1 Chemical Energy and ATP
• Cells require chemical energy.
• This energy is carried by Adenosine Triphosphate (ATP)
• ATP is a molecule that transfers energy from the
breakdown of food molecules to cell functions.
• ATP is used by cells to build molecules, move materials
(active transport), etc.
4.1 Chemical Energy and ATP
• ATP, which has 3 phosphates, powers cell functions by
releasing the third phosphate and becoming ADP.
– Energy is released when a phosphate group is removed,
the reaction removing P releases energy.
– ADP is changed back into ATP when a phosphate group
is added (Cycle).
phosphate removed
4.1 Chemical Energy and ATP
Organisms break down carbon-based molecules to
produce ATP.
• Carbs, lipids, and proteins are broken down to make ATP.
• Carbos are most commonly broken down to make ATP.
triphosphate
– not stored in large amounts adenosine
– up to 36 ATP from one
glucose molecule
tri=3
adenosine
di=2
diphosphate
4.1 Chemical Energy and ATP
• Which molecules store the most energy?
• Fats store the most energy.
– 80 percent of the energy in your body
– about 146 ATP from a triglyceride
• Proteins are least likely to be broken down to make ATP.
– amino acids not usually needed for energy (protein)
– about the same amount of energy as a carbohydrate
4.1 Chemical Energy and ATP
A few types of organisms do not need sunlight and
photosynthesis as a source of energy.
• Some organisms live in places
that never get sunlight.
• In chemosynthesis, chemical
energy is used to build
carbon-based molecules.
– similar to photosynthesis
– uses chemical energy
instead of light energy