BIO 101 Chapter 2B

Organic molecule

compound containing carbon and hydrogen

Hydrocarbons

compound made up of just carbon and hydrogen

How does the structure of carbon contribute to the diversity of organic molecules?

Carbon is made up of 6 electrons. It has 4 valence electrons in the outer ring. It seeks 4 more electrons to make it stable. Therefore, it can form four covalent bonds with other atoms. This allows carbon to form varying chains and structures with other atoms.

Structural isomer

same molecular formula, arranged differently

What are the four classes of large (biologically important) organic molecules?

Carbohydrates, proteins, nucleic acids, lipids

Monomer

single unit of polymer

Polymer

collection of monomers (similar subunits)

Dehydration synthesis

enzyme removes hydroxyl group from one molecule and hydrogen atom from another, forming H2O and a new covalent bond between the molecules. Loss of water

Hydrolysis

splitting covalent bonds between monomers by adding water. One molecule receives hydroxyl group, and another receives a hydrogen atom.

Carbohydrates

compound containing carbon, hydrogen, oxygen (1:2:1)

Two main carbohydrate groups

Simple carbohydrates (monosaccharides and disaccharides) and complex carbohydrates (oligosaccharides, glycoprotein, polysaccharides)

Monomer of carbohydrates

monosaccharides

Glycosidic bonds

covalent bonds that link monosaccharides

Disaccharides

two monosaccharides joined by dehydration synthesis

Oligosaccharides

3-100 monosaccharides

Polysaccharides

100+ monosaccharides

Energy storage polysaccharides in plants

Starch

Energy storage polysaccharides in animals

Glycogen

Structural polysaccharide in plants

Cellulose

Structural polysaccharide in animals

Chitin

Monomer of proteins

amino acids

How many types of amino acids are there?

20

Peptide bond

Covalent bond between adjacent amino acids, from dehydration synthesis.

Peptides

2-99/<100 amino acids.

Polypeptides

100+ amino acids.

Proteins

Polypeptide(s) folded into functional 3-D shape.

What is one of the most important roles of proteins in cells?

catalyst/enzyme; to increase the rate of speed in reactions.

Protein denaturation

Modification of protein shape, so that its function is destroyed.

Conditions for denaturation

Extremes of temperature and pH.

Types of proteins

Structural (collagen), contractile (muscles), transport (membrane channel proteins), storage (egg protein), enzyme (digestive), antibodies.

Primary structure

Linear, amino acid sequence of polypeptide.

Secondary structure

Folded into coils, sheets, loops.

Tertiary structure

Overall shape of polypeptide.

Quaternary structure

Overall protein shape, multiple polypeptides.

Five components of amino acids

R group, central carbon, hydrogen atom, amino group, carboxyl group.