Description of Chemical Energy and ATP

Contributed by:
Sharp Tutor
We will discuss the chemical energy produced inside a cell for overall functioning. Adenosine triphosphate (ATP) is an organic compound and hydrotrope that provides energy to drive many processes in living cells, such as muscle contraction.
1. 4.1 Chemical Energy and ATP
KEY CONCEPT
All cells need chemical energy.
2. 4.1 Chemical Energy and ATP
The chemical energy used for most cell processes is
carried by ATP.
• Molecules in food store chemical energy in their bonds.
Starch molecule
Glucose molecule
3. 4.1 Chemical Energy and ATP
• ATP transfers energy from the breakdown of food
molecules to cell functions.
– Energy is released when a phosphate group is removed.
– ADP is changed into ATP when a phosphate group is
added.
phosphate removed
4. 4.1 Chemical Energy and ATP
Organisms break down carbon-based molecules to
produce ATP.
• Carbohydrates are the molecules most commonly broken
down to make ATP.
– not stored in large amounts adenosine triphosphate
– up to 36 ATP from one
glucose molecule
tri=3
adenosine diphosphate
di=2
5. 4.1 Chemical Energy and ATP
• 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
– about the same amount of energy as a carbohydrate
6. 4.1 Chemical Energy and ATP
A few type of organisms do not need sunlight and
photosynthesis as a source of energy.
• Most organisms rely directly or indirectly on sunlight and
photosynthesis.
• Organisms that live in the deep ocean near hydrothermal
vents do not.
• These organisms, Chemotrophs, use chemicals from the
vents as an energy source.
• Chemosynthesis is the process by which some
organisms use chemical energy instead of light energy to
make carbon based molecules.
• These organisms still generate ATP as an energy source.
7. 4.1 Chemical Energy and ATP
Exercises
• How are ATP and ADP related?
• What types of molecules are broken down to make ATP?
Which are most often broken down to make ATP?
• How are some organisms able to survive without sunlight
and photosynthesis?
• Describe how you do not get energy directly from the food
that you eat.
• How are the energy needs of a plant cell similar to those
of an animal cell? How are they different?
• A water molecule is added to an ATP molecule to break
down ATP into ADP and a phosphate. Write a chemical
equation that represents this reaction.