ATP Energy Carrier

• It is the energy released from the breakdown of food and transferred in molecules called Adenosine triphosphate (ATP). When energy is needed by the cell, it is converted from storage molecules into ATP. ATP then serves as a shuttle, delivering energy to places within the cell where energy-consuming activities are taking place.

• ATP was first discovered by the German chemist Karl Lohmann in 1929.

• An immediate source of energy for all cellular activities

• Is often referred to as the cell's "energy currency."

• A key reaction for metabolism

• Is a vital "energy molecule" found in all living things.

• Plants use ATP molecules to collect and store the energy they get from light during photosynthesis.

• An energy-carrying molecule found in the cells of all living things.

• It is the source of energy for use and storage at the cellular level.

FUNCTION OF ATP

• Energy is released as a result of the hydrolysis of ATP and the creation of adenosine diphosphate (ADP).

• Is used in signal transduction pathways for cell communication

• is responsible for supplying most of the energy needs of living organisms.

• In photosynthesis, the role of ATP is to carry the energy of the Calvin cycle that occurs in the absence of light.

• Functions as a carrier of energy in all living organisms from bacteria and fungi to plants and animals including humans.

ATP STRUCTURE

It consists of 3 main structures: Adenine, ribose, and a chain of 3 phosphate groups bonded to ribose.

1. Adenine - the nitrogenous base. It is employed to produce nucleotides for nucleic acids.

2. Ribose sugar - is a simple sugar made in the body from glucose. It plays an important role in the energy-containing substance adenosine triphosphate (ATP). It naturally occurring five-carbon sugar produced in the body through the PPP.

3. Adenosine - a nucleoside when adenine binds to a ribose.

4. Phosphate - the key to its ability to store and supply energy

ATP - ADP CYCLE

• The energy stored in ATP is released when a phosphate group is removed from the molecule.

• ATP has three phosphate groups, but the bond holding the third phosphate group is very easily broken.

• When the phosphate is removed, ATP becomes ADP—adenosine diphosphate.

• A phosphate is released into the cytoplasm and energy is released.

• ADP is a lower energy molecule than ATP but can be converted to ATP by the addition of a phosphate group.

• ATP → ADP + phosphate + energy available for cell processes.

ATP is produced from ADP and phosphate ions by a complex set. A process that takes place inside a cell. These processes are enzymes. The key enzymes are Nicotinamide Adenine Dinucleotide (NAD), Nicotinamide Adenine Dinucleotide Phosphate (NADP), and flavin dinucleotide (FAD). Both NAD and NADP are structurally similar to ATP. Both molecules have the nitrogen ring cell nicotinic acid chemically bound to the active portion of the coenzyme. In FAD, the chemically active part is the flavin group, which is made from the vitamin in the body Riboflavin.

All coenzymes eventually perform the same function. During the chemical reactions of metabolism coenzymes accept electrons and pass them on to other coenzymes or other molecules. The removal of electrons/protons from coenzymes is called oxidation; the addition of electrons to a molecule is reduction. Hence, the chemical reactions performed by the coenzymes are called oxidation-reduction reactions.

ATP VS. ADP