Energy in a Cell

Chapter 9.1

Images copied from ftexploring.com

Cell Energy

• Energy is essential to life.

• Plants trap light energy from the sun

• Animals eat plants to obtain the energy stored in plants.

•Food molecules are the $1000 dollar bills of energy storage

•Food molecules function as fuel molecules, storing large quantities of energy in a stable form over long periods of time! They are the long-term energy currency of the cell.

•For “pocket change”, cells require a molecule that stores much smaller quantities of energy and that can be used and re-charged!

•This molecule is adenosine triphosphate or ATP !!!!!

•ATP collects small packets of energy from the food burning power plants(mitochondria) of the cell and transports this energy to where it is needed!

•ATP moves muscles or forces a seedling out of the ground or forms sucrose in the cells or….. or……. or…….

Adenosine Triphosphate

• ATP• The energy molecule in your cells

that is a quick source of energy for any organelle that needs it.

• Stored in the chemical bonds• Composed of an adenosine molecule

and 3 phosphate groups

ATP

Forming and Breaking Down ATP

•AMP: adenosine monophosphate

•ADP: adenosine diphosphate

•ATP: adenosine triphosphate

Forming and Breaking Down ATP

• AMP= 1 Phosphate group bonds: a small amount of energy is required to push the bonds together. A small amount of energy is stored in the chemical bond.

• ADP= 2 Phosphate groups bond: more energy is required to force the bonds together and more energy is stored.

Charged Phosphate groups act like the positive poles of two magnets.

They Repel!

Forming and Breaking Down ATP

• ATP:3 Phosphate groups bond and an even greater amount of energy is required and stored.

• When the bonds are broken energy is released.

• The energy becomes available to a cell when the molecule is broken down.

ATP Cycle

• When the chemical bond between the 2nd and 3rd phosphate groups in ATP is broken, energy is released and ADP is left.

• ADP then forms ATP again by bonding with another phosphate group.

ATP Cycle

• The formation and breakdown cycle is important because it relieves the cell of having to store all the ATP it needs.

• An average male produces 17 lbs. Of ATP an hour.

How cells tap into the energy stored in ATP.

• When ATP is broken down and the energy is released the energy must be captured and used efficiently by the cells.

• Proteins have a specific site where ATP can bind.

• When the phosphate bond is broken and energy is released, the cell can use the energy.

Uses for Cell Energy

• Making new molecules

• Building membranes and cell organelles

• Maintain Homeostasis

• Eliminate waste

• Transmit nerve impulses

•When a fatty acid is burned, energy is given off. Some of this energy is trapped in the molecules of ATP and some is lost in the form of HEAT !

•The energy carrying part of an ATP molecule is the triphosphate “tail”. Three phosphate groups are joined by covalent bonds. The electrons in these bonds carry ENERGY !

ADENINERIBOSE SUGAR

TRI PHOSPHATE(3 PHOSPHATES)

ATP OR ADENOSINE TRIPHOSPHATE

Draw and Label the ATP molecule