<< Chapter < Page Chapter >> Page >

Structure of adenosine triphosphate (atp)

This figure shows the structure of ATP.

When a phosphate group is cleaved from ATP, the products are adenosine diphosphate (ADP) and inorganic phosphate (P i ). This hydrolysis reaction can be written:

ATP + H 2  ADP + P i  + energy

Removal of a second phosphate leaves adenosine monophosphate (AMP) and two phosphate groups. Again, these reactions also liberate the energy that had been stored in the phosphate-phosphate bonds. They are reversible, too, as when ADP undergoes phosphorylation. Phosphorylation is the addition of a phosphate group to an organic compound, in this case, resulting in ATP. In such cases, the same level of energy that had been released during hydrolysis must be reinvested to power dehydration synthesis.

Cells can also transfer a phosphate group from ATP to another organic compound. For example, when glucose first enters a cell, a phosphate group is transferred from ATP, forming glucose phosphate (C 6 H 12 O 6 —P) and ADP. Once glucose is phosphorylated in this way, it can be stored as glycogen or metabolized for immediate energy.

Chapter review

Organic compounds essential to human functioning include carbohydrates, lipids, proteins, and nucleotides. These compounds are said to be organic because they contain both carbon and hydrogen. Carbon atoms in organic compounds readily share electrons with hydrogen and other atoms, usually oxygen, and sometimes nitrogen. Carbon atoms also may bond with one or more functional groups such as carboxyls, hydroxyls, aminos, or phosphates. Monomers are single units of organic compounds. They bond by dehydration synthesis to form polymers, which can in turn be broken by hydrolysis.

Carbohydrate compounds provide essential body fuel. Their structural forms include monosaccharides such as glucose, disaccharides such as lactose, and polysaccharides, including starches (polymers of glucose), glycogen (the storage form of glucose), and fiber. All body cells can use glucose for fuel. It is converted via an oxidation-reduction reaction to ATP.

Lipids are hydrophobic compounds that provide body fuel and are important components of many biological compounds. Triglycerides are the most abundant lipid in the body, and are composed of a glycerol backbone attached to three fatty acid chains. Phospholipids are compounds composed of a diglyceride with a phosphate group attached at the molecule’s head. The result is a molecule with polar and nonpolar regions. Steroids are lipids formed of four hydrocarbon rings. The most important is cholesterol. Prostaglandins are signaling molecules derived from unsaturated fatty acids.

Proteins are critical components of all body tissues. They are made up of monomers called amino acids, which contain nitrogen, joined by peptide bonds. Protein shape is critical to its function. Most body proteins are globular. An example is enzymes, which catalyze chemical reactions.

Nucleotides are compounds with three building blocks: one or more phosphate groups, a pentose sugar, and a nitrogen-containing base. DNA and RNA are nucleic acids that function in protein synthesis. ATP is the body’s fundamental molecule of energy transfer. Removal or addition of phosphates releases or invests energy.

Watch this video to observe the formation of a disaccharide. What happens when water encounters a glycosidic bond?

The water hydrolyses, or breaks, the glycosidic bond, forming two monosaccharides.

Got questions? Get instant answers now!

Questions & Answers

can the teeth be classify under bones?
Ojaga Reply
Bony prominents
What is the largest muscle in the lower leg
Gwen Reply
what's a nervous system
Dante Reply
Is a the group of neurons and glial cells that work together to receive, integrate and responds appropriately to stimulus in the periphery, spinal cord and brain.
study about internal structure, outer structure and their functions
Navdeep Reply
circulatory system on blood pressure
Lakhu Reply
What is ELISA
(enzyme linked immunosorbent assay) is a test that uses antibodies and color change to identify a substance.
what's defense mechanism?
psychological strategies that are unconsciously used to protect a person from anxiety arising from unacceptable thoughts or feelings.
difference between apocrine sweat glands and merocrine sweat glands
Binkheir Reply
I believe the apocrine sweat gland uses a sac under the hair follicle and the merocrine sweat gland releases directly on to the surface of the skin
normal blood volume in our body
pankaj Reply
Normal blood volume in adults is 6 litres
4.7 to 5ltr.. normal for adult
what are the advantages of the concave shape of red blood cells?
Amy Reply
This structure is VERY flexible. It can allow these cells to get into the most tiny places in our bodies. a VERY good design! The advantage of red blood cells' biconcave shape is that the surface area is increased to allow more haemoglobin to be stored in the cell.
They can stack so that they can move to capillaries
action of gluteus medius and minimus
Green Reply
Lateral rotation of the hip joint
Briefly explain location of ecg on a patient
Prince Reply
it is a machine that gives a graphical representation of heart beat
Briefly explain location of ecg leads on a patient?
in ecg we use electrical leads over the chest ,ancle and wrist
what is the anatomical and function difference between paravertebral and prevertebral ganglia ?
Rada Reply
types of tissue in human
Preety Reply
charactetistic Of cartilaginous tissue
what is theRecurrent infection?
pankaj Reply
what do you mean about recurrent infection
Recurrent or persistent infection is a manifestation of primary immuno deficiency
weakens the immune system, allowing infections and other health problems to occur more easily
lysis of RBC
What is barometric pressure
Kedha's Reply

Get the best Anatomy & Physiology course in your pocket!

Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Anatomy & Physiology' conversation and receive update notifications?