8.1 - Energy & Life

ATP as a Charged Battery

ADP is like a rechargeable battery that powers the machinery of the cell. Similar to a battery being charged, ADP becomes "fully charged" when it is converted to the higher-energy molecule ATP. The energy from ATP powers many cell processes. ATP's energy is released by breaking the bond between the second and third phosphate group, which then converts ATP back into ADP. When a phosphate group is added to an ADP molecule, ATP is produced. ADP contains some energy, but not as much as ATP. In this way, ADP is like a partially charged battery than can be fully charged by the addition of a phosphate group.

Why is ATP useful to cells?

ATP can easily release and store energy by breaking and re-forming the bonds between its phosphate groups. This characteristic of ATP makes it exceptionally useful as a basic energy source for all cells.

What is the difference between ATP and ADP?

ATP has three phosphates; ADP has two.

Using Biochemical Energy

ATP powers movement, providing the energy for motor proteins that contract muscles and power the wavelike movement of cilia and flagella. Energy from ATP powers the synthesis of proteins and responses to chemical signals at the cell surface.

Energy is release upon the conversion of

ATP to ADP.

Adenosine triphosphate (ATP)

Compound used by cells to store and release energy. Adenine, Ribose, 3 phosphate groups.

Autotrophs and Hetertrophs

Grass, an autotroph, uses energy from the sun to produce food. Cheetahs, in turn, get their energy by eating other organisms that ate the grass.

What happens during the process of photosynthesis?

In the process of photosynthesis, plants convert the energy of sunlight into chemical energy stored in the bonds of carbohydrates.

Why are mushrooms considered heterotrophs?

Mushrooms feed by absorbing decomposing nutrients from organisms.

Autotroph

Organism that is able to capture energy from sunlight or chemicals and use it to produce its own foods from inorganic compounds; also called a producer.

Heterotroph

Organism that obtains food by consuming other living things; also called a consumer.

Photosynthesis

Process used by plants and other autotrophs to capture light energy and use it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugars and starches.

Obtain

To get or to gain. Organisms must obtain energy in order to carry out life functions.

Organisms that make their own food are called

autotrophs.

One way cells use the energy provided by ATP is to

carry out active transport.