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.

Carbohydrate video

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.

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