ATPSC.912.L.18.10

ESSENTIAL QUESTION

How is ATP related to energy transfer in the cell?

How is ATP generated in the mitochondria and the chloroplast.

How is energy stored and released by ATP?

Have you ever used a rechargeable battery?

Well, every living thing uses the same molecule for the short-term storage of energy. It is called ATP. The function of this molecule

can be compared to a rechargeable battery.

This molecule is called the energy currency of ALL living things!

This is a graphic representation of ATP

Notice the three main parts of ATP:

1. Adenine – a nitrogenous base2. Ribose – a sugar3. 3 Phosphate molecules

• All living organisms must be able to obtain energy from the environment in which they live.

• Plants and other green organisms are able to trap the light energy in sunlight and store it in the bonds of certain molecules for later use.

Cell EnergyCell Energy

• Other organisms cannot use sunlight directly.

Cell EnergyCell Energy

•When bonds are broken energy is released and generally, energy is needed to form bonds.•The fewer phosphates, the less energy these molecules have because they have fewer bonds from which to release energy.

Adenosine diphosphate(Half-charged battery)

Adenosine monophosphate(dead battery)

• The charged phosphate groups act like the positive poles of two magnets.

• Bonding three phosphate groups to form adenosine triphosphate requires considerable energy.

Forming and Breaking Down ATPForming and Breaking Down ATP

• When only one phosphate group bonds, a small amount of energy is required and the chemical bond does not store much energy. This molecule is called adenosine monophosphate (AMP).

Forming and Breaking Down ATPForming and Breaking Down ATP

• When a second phosphate group is added, more energy is required to force the two groups together. This molecule is called adenosine diphosphate, or ADP.

• An even greater amount of energy is required to force a third charged phosphate group close enough to the other two to form a bond. When this bond is broken, energy is released.

Forming and Breaking Down ATPForming and Breaking Down ATP

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

Adenosine

Adenosine

P P P

P

P

P P

Adenosine triphosphate (ATP)

Adenosine diphosphate (ADP)

Forming and Breaking Down ATPForming and Breaking Down ATP

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

• Many proteins have a specific site where ATP can bind.

How cells tap into the energy stored in ATPHow cells tap into the energy stored in ATP

• When ATP has been broken down to ADP, the ADP is released from the binding site in the protein and the binding site may then be filled by another ATP molecule.

How cells tap into the energy stored in ATPHow cells tap into the energy stored in ATP

ATP SYNTHESIS IN THE MITOCHONDRION AND THE CHLOROPLAST

DAY 2:

Chemiosmosis - http://www.tvdsb.on.ca/westmin/science/Biology12/Metabolic%20Processes/chemios.htm

ATP Production during Aerobic Respiration by Oxidative Phosphorylation involving an Electron Transport System and Chemiosmosis http://student.ccbcmd.edu/courses/bio141/lecgui

de/unit6/metabolism/cellresp/chemioar.html

Question 1

What is the primary difference in the ways that plants and animals obtain energy?

Answer

All living organisms need energy. Plants can trap light energy in sunlight and store it for later use. Animals cannot trap energy from sunlight and must eat plants that contain stored energy.

Question 2

Why does the formation of ATP require energy?

One molecule of ATP contains three phosphate groups, which are charged particles. Energy is required to bond the phosphate groups onto the same molecule because they behave the same way that the poles of magnets do and repel groups with like charges. When the ATP molecule is broken down, the chemical energy stored in it becomes available to the cell for life processes.

Question 3

A molecule of adenosine that has one phosphate group bonded to it is.A. AMP

B. ADP

C. ATP

D. ACP

The answer is A. AMP is adenosine monophosphate.

The addition and release of a phosphate group on adenosine diphosphate creates a cycle of ATP formation and breakdown.

Adenosine

Adenosine

P P P

P

P

P P

Adenosine triphosphate (ATP)

Adenosine diphosphate (ADP)

Question 4

What is the function of the protein molecule shown in this diagram? ATP

ADP

ADP

Protein P Energy

This protein molecule has a specific binding site for ATP. In order to access the energy stored ATP, the protein molecule binds the ATP and uncouples one phosphate group. This action releases energy that is then available to the cell.

ATP

ADP

ADP

ProteinP Energy