Download ppt - Chemical Energy and ATP KEY CONCEPT All cells need chemical energy

Chemical Energy and ATP

KEY CONCEPT All cells need chemical energy.


• The cells of all organisms—from algae to whales to people—need chemical energy for all of their processes.

• Some organisms, such as diatoms and plants, absorb energy from sunlight. What is a diatom?– What do they do with it?

- Some of that energy is stored in sugars. - Cells break down sugars to produce usable

chemical energy for their functions.

Without organisms that make sugars, living things on Earth could not survive.


MAIN IDEA: The chemical energy used for most cell processes is carried by ATP.

You are hungry. You need energy, so you grab what? A Snickers Bar? A Kit-Kat Bar?

Does this food that contains sugar and other Carbon-based molecules give you the energy that you need? How does it provide it to you, exactly?

All carbon-based molecules store chemical energy in their bonds!


• Molecules in food store chemical energy in their bonds.• What is a glucose molecule?

Starch molecule

Glucose moleculeA six-carbon sugar

made by plants during photosynthesis.Used for energy!


What is ATP?Adenosine triphosphate, a molecule that transfers energy from the breakdown of food molecules to cell processes.

• ATP carries chemical energy that cells can use.• Cells use ATP to carry out functions:

– building molecules – moving materials by active transport.


phosphate removed

How does ATP transfer energy from the breakdown of food molecules to cell functions?

– ATP has three phosphate groups, but the third has a unstable, weak bond.

– Energy is released when the third phosphate group is removed.– ADP is changed into ATP when a phosphate group is added.

ADP is a lower-energy molecule that can be converted into ATP by the addition of a phosphate group.


Where are molecules from food involved in the cycle?

phosphate removed

Food molecules are supplying the energy to

ADD a phosphate

group to ADP, converting it

once again to ATP!


Describe the relationship between energy stored in food and ATP.

1. Food molecules store chemical energy in their bonds.

2. Food is broken down into smaller molecules that are broken down further to transfer this energy to ATP.


Let’s Compare ATP and ADP!


Organisms break down carbon-based molecules to produce ATP.• Food does not contain readily useable ADP that our cells

can use.• Food has to be eaten and digested first (making smaller

molecules)• Different foods contain different amounts of calories,

which is a measure of energy. Calories and ATP are related.

• Different foods contain different amounts of ATP.• The number of ATP molecules produced depends on the

type of molecule that is broken down– Carbohydrate– Lipid– Protein


Fill in the Details Section in the table on your Power Notes!

Carbohydrates are the molecules most commonly broken down to make ATP.

– not stored in large amounts in our bodies

– you can get up to 36 ATP molecules from one glucose molecule


• Lipids or Fats store the most energy and provide the most ATP when broken down.

– Store 80 percent of the energy in your body– Obtain about 146 ATP molecules from a triglyceride

• Proteins are least likely to be broken down to make ATP.– amino acids not usually needed for energy, but for making

new proteins!– store about the same amount of energy as a carbohydrate


What about plants?More on them later…………….

• Lipids provide more ATP than carbohydrates do.• Carbohydrates produce about 36, and lipids produce

about 146.

Compare and Contrast:How do lipids and carbohydrates differ in ATP production?


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 (hydrothermal vents)

• These vents release chemical compounds

• In chemosynthesis, organisms use chemical energy instead of light energy to make energy-storing carbon-based molecules.

• Process is – similar to photosynthesis– uses chemical energy

instead of light energy


How are chemosynthetic organisms and plants similar as energy sources?

• Both chemosynthetic organisms and plants make their own food and both are eaten by other organisms that cannot make their own food.