Download Organic compounds Carbon compounds are also called organic

Organic compounds
Carbon compounds are also called organic compounds. Most of these molecules are
very large and made up of smaller building blocks or sub-units. Four groups of organic
molecules that are related to the survival of living things are; carbohydrates, lipids, nucleic acids
and proteins.
Carbohydrates are compounds made up of carbon, hydrogen and oxygen atoms in a
1:2:1 ratio. They are all made up of monosaccharide subunits. They are commonly called “the
sugars”, and are used by living things as their main source of energy. Glucose or “blood sugar”
is one of the few simple sugars known as monosaccharides. Starch, cellulose and glycogen are
complex carbohydrates known as polysaccharides. Starch is produced by plants to store many
glucose molecules. Cellulose is also made up of glucose and is used by plants to produce cell
walls. Glycogen is used by animals to store excess glucose.
Lipids are made mostly from carbon and hydrogen atoms with a few oxygen atoms. Fats
and oils are lipids. Lipids are used in living things to store energy. Phospholipids are lipids that
make up biological membranes. They are composed of fatty acid and glycerol building blocks.
Steroids are also a type of lipid. There are many different types of steroids with different
functions, but all can be recognized by their 4 fused carbon-ring structure.
Proteins contain nitrogen as well as carbon, hydrogen and oxygen. Proteins are large
folded molecules made of amino acid sub-units. There are many proteins with many different
functions including those that play a role in cell communication, those that make up cell
membranes, and those that help fight disease. Enzymes are proteins that speed up chemical
reactions. Insulin is a protein that regulates blood sugar levels and hemoglobin is a protein that
enables red blood cells to carry oxygen.
Nucleic acids contain hydrogen, oxygen, nitrogen, carbon and phosphorus. Nucleotides
are the sub-units that make up nucleic acids. Each nucleotide consists of a sugar, a phosphate
group and a nitrogen base. Nucleic acids store and transmit hereditary, or genetic, information.
There are two kinds of nucleic acids; DNA and RNA.