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10 Molecules Found In Animals


A molecule is the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules are made up of atoms that are held together by chemical bonds. These bonds form as a result of the sharing or exchange of electrons among atoms. The atoms of certain elements readily bond with other atoms to form molecules. Examples of such elements are oxygen and chlorine. The atoms of some elements do not easily bond with other atoms. Examples are neon and argon.

Molecules can vary greatly in size and complexity. The element helium is a one-atom molecule. Some molecules consist of two atoms of the same element. For example, O2 is the oxygen molecule most commonly found in the earth's atmosphere; it has two atoms of oxygen. However, under certain circumstances, oxygen atoms bond into triplets (O3), forming a molecule known as ozone. Other familiar molecules include water, consisting of two hydrogen atoms and one oxygen atom (H2O), carbon dioxide, consisting of one carbon atom bonded to two oxygen atoms (CO2), and sulfuric acid, consisting of two hydrogen atoms, one sulfur atom, and four oxygen atoms (H2 SO4).

Some molecules, notably certain proteins, contain hundreds or even thousands of atoms that join together in chains that can attain considerable lengths. Liquids containing such molecules sometimes behave strangely. For example, a liquid may continue to flow out of a flask from which some of it has been poured, even after the flask is returned to an upright position.

Molecules are always in motion. In solids and liquids, they are packed tightly together. In a solid, the motion of the molecules can be likened to rapid vibration. In a liquid, the molecules can move freely among each other, in a sort of slithering fashion. In a gas the density of molecules is generally less than in a liquid or solid of the same chemical compound, and they move even more freely than in a liquid. For a specific compound in a given state (solid, liquid, or gas), the speed of molecular motion increases as the absolute temperature increases.


1. Glucose C6H12O6

Glucose is a monosaccharide (sugar) which is one of the basic carbohydrates in the body. It is made up of 6 carbon atoms,12 hydrogen atoms and 6 oxygen atoms.

2. Keratin C28H48N2O32S4

Keratin is a type of protein which makes up an animal’s fur, feathers, wool, scales, nails, horns

and hooves. It also protects the epithelial cells which surround internal organs. It is made up of 28 carbon atoms, 48 hydrogen atoms, 2 nitrogen atoms, 32 oxygen atoms and 4 sulphur atoms.

3. Melanin C18H10N2O4

Melanin is a pigment in the body which is responsible for dark or black colouring of an animal’s hair, skin and scales, as well as the iris of the eye.

It is made up of 18 carbon atoms, 10 hydrogen atoms, 2 nitrogen atoms and 4 oxygen atoms.

4. Collagen C65H102N18O21

Collagen is a structural protein found in the bones, skin, muscles, tendons and blood. It is made up of 65 carbon atoms, 102 hydrogen atoms, 18 nitrogen atoms and 21 oxygen atoms.

5. Estradiol C18H24O2

Estradiol (also spelled Oestradiol) is a type of estrogen (female sex hormone) naturally produced in male and female animals; however, it is more prominent in females. It is responsible for the development of reproductive tissues such as the mammary glands, ovaries, testes and adrenal gland. It is made up of 18 carbon atoms, 24 hydrogen atoms and 2 oxygen atoms.

6. Testosterone C19H28O2

Testosterone is a male sex hormone naturally produced in in male and female animals, however it is more prominent in males. It is responsible for the development of reproductive tissues such as the penis, testes, prostate, ovaries and adrenal gland. It is made up of 19 carbon atoms, 28 hydrogen atoms and 2 oxygen atoms.

7. Cholesterol C27H46O

Cholesterol is a type of lipoprotein found in all the cells in an animal’s body. It is used to build cell walls, produce hormones and vitamin D and aid in digestion. It is made up of 27

carbon atoms, 46 hydrogen atoms and 1oxygen atom.

8. Serotonin C10H12N2O

Serotonin is a neurotransmitter (chemical) which sends signals between the nerve cells. It affects the animal’s mood, bowel movements, sleep, coagulation, healthy bones, and the healing process in wounds. It is made up of 10 carbon atoms, 12 hydrogen atoms, 2 nitrogen atoms and 1 oxygen atom.

9. Dopamine C8H11NO2

Serotonin is a neurotransmitter (chemical) which sends signals in the animal’s brain. It affects the animal’s movements and emotional wellbeing and is responsible for it recognising rewards and enjoyable activities. It is made up of 8 carbon atoms, 11 hydrogen atoms, 1 nitrogen atoms and 2 oxygen atoms.

10. Water H2O

Water is one of the main and most important molecules in the body. In animals about 60% of the body weight is water. It is made up of 2 Hydrogen atoms and 1 oxygen atom.

By: TISOVN Student Emma - Certificate in Animal Care 1

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