Organic Compounds

Necessities for Life

Special Chemicals of Life

What is an organic compound?

In Biology, the word organic means “relating to organisms” NOT food grown without the use of pesticides, antibiotics, or other industrial chemicals.

All organic compounds contain covalently bound carbon & hydrogen.

Organic compounds can also be synthesized in the lab.

Why is carbon ideal for making different compounds?

Carbon atoms have four valence (outer shell) electrons, allowing carbon to form covalent bonds with many elements including hydrogen, oxygen, phosphorus, sulfur and nitrogen.

Carbon can also bond to other carbon atoms, which gives carbon the ability to form chains that are almost unlimited in length.

These carbon-carbon bonds can be single, double, or triple.

The chains be straight, branched, or even ring-shaped. Therefore, carbon is unique in that it can form millions

of different large and complex structures.

What are macromolecules?

They are giant molecules which are made from many smaller molecules.

How are macromolecules made?

Polymerization is how macromolecules are formed!

This process joins smaller units (monomers) together to form larger compounds (polymers).

(Like placing beads together to make a necklace.)

Four Groups of Organic Compounds

Carbohydrates Lipids Nucleic acids Proteins

….are needed by all living things.

Carbohydrates (sugars)

main source of energy for organisms can also be used for structural purposes made of C, H, and O; usually in a 1:2:1 ratio The monomers of carbohydrates are called

monosaccharides: glucose, fructose (in fruits) and galactose (in milk).– The breakdown of monosaccharides supplies

immediate energy through cellular respiration. – usually end in –ose.

Carbohydrates cont’d

Extra sugar is stored as macromolecules called polysaccharides.

Polysaccharides are made from monosaccharides.

Uses of Polysaccharides

Animals store extra sugar as glycogen.– Glycogen stored in your muscle supplies energy

for contractions. – Glycogen stored in your liver is released when

glucose in your blood runs low.

Plants store excess sugar as starch. – Can also make cellulose, a strong, rigid fiber

used for support in cell walls.

Carbohydratevideo

Lipids (fats, oils, and waxes)

uses: – long-term energy storage, – insulation, – waterproof covering, – part of cell membranes, – chemical messengers (steroids)

contain mostly C, H & O generally not soluble in water

Lipids

Many lipids are formed when a glycerol molecule combines with fatty acids.

If all carbon atoms have only single bonds, the lipid is saturated. It holds as many hydrogen atoms as possible.

Lipids

If there is at least one double bond between carbon atoms, the lipid is unsaturated.

Unsaturated lipids like cooking oils tend to be liquid at room temperature.

Nucleic Acids

store and transmit genetic information

contain H, C, N, O, and phosphorus (P)

The monomers of nucleic acids are nucleotides which contain three parts:

– a 5-carbon sugar– a phosphate group, – a nitrogen base.

examples: DNA and RNA

Proteins are macromolecules.

contain C, H, O, N, & most also have sulfur (S)

The monomers of proteins are amino acids which contain:– an amino group, a carboxyl group, and a variable

R-group.

Proteins have many functions

Provide structural support in bones and muscles,

Form parts of cell membranes,

Function as hormones to regulate the body,

Form antibodies to protect against infection,

Increase the rate of chemical reactions to name a few.

• When the amino acids join, they form a polymer called a polypeptide. The monomers are held together by peptide bonds.

• More than 20 different amino acids are found in nature. • Since the R-group varies, it allows for much variety. That

is why proteins have so many functions.

Proteins have four levels of organization.

• This allows for the unique shape of proteins.

• Shape is very important; if a protein is not the right shape, it will not work.

Enzymes – a special type of protein

A type of protein, which speeds up a chemical reaction.

Without enzymes, several reactions in cells would never happen.

Proteins