BIOCHEMISTRY

Aim: How do we compare the stuctures and function of the four major families of biological macromolecules? Do now: Define organic compound. Vocabulary: carbohydrates, proteins, fats, nucleic acids

And now for the Biochemistry portion of things….

ORGANIC COMPOUNDS LIPIDS PROTEINS NUCLEIC ACIDS CARBOHYDRATES

CARBOHYDRATES Living things use carbohydrates as a key source of ENERGY! Plants use carbohydrates for structure (CELLULOSE) include sugars and complex carbohydrates (starches) contain the elements carbon, hydrogen, and oxygen (the hydrogen is in a 2:1 ratio to oxygen)

Monosaccharides (simple sugars) all have the formula C6 H12 O6 all have a single ring structure (glucose is an example)

Disaccharides (double sugars) all have the formula C12 H22 O11 sucrose (table sugar) is an example

Polysaccharides Formed of three or more simple sugar units Glycogen - animal starch stored in liver & muscles Cellulose - indigestible in humans - forms cell walls Starches - used as energy storage

How are complex carbohydrates formed and broken down?

Dehydration Synthesis Combining simple molecules to form a more complex one with the removal of water ex. monosaccharide + monosaccharide ----> disaccharide + water (C6H12O6 + C6H12O6 ----> C12H22O11 + H2O Polysaccharides are formed from repeated dehydration syntheses of water They are the stored extra sugars known as starch

Hydrolysis Addition of WATER to a compound to SPLIT it into smaller subunits (also called chemical digestion) ex. disaccharide + H2O ---> monosaccharide + monosaccharide C12 H22 O11 + H2 O ---> C6 H12 O6 + C6 H12 O6

Lipids (Fats) Fats, oils, waxes, steroids Chiefly function in energy storage, protection, and insulation Contain carbon, hydrogen, and oxygen but the H:O is not in a 2:1 ratio Tend to be large molecules -- an example of a neutral lipid is below

Neutral lipids are formed from the union of one glycerol molecule and 3 fatty acids 3 fatty acids + glycerol ----> neutral fat (lipid) Fats -- found chiefly in animals Oils and waxes -- found chiefly in plants Oils are liquid at room temperature, waxes are solids Lipids along with proteins are key components of cell membranes Steroids are special lipids used to build many reproductive hormones and cholesterol

PROTEINS contain the elements carbon, hydrogen, oxygen, and nitrogen composed of MANY amino acid subunits It is the arrangement of the amino acid that forms the primary structure of proteins. The basic amino acid form has a carboxyl group on one end, a methyl group that only has one hydrogen in the middle, and a amino group on the other end. Attached to the methyl group is a R group.

AN R GROUP IS ANY GROUP OF ATOMS – THIS CHANGES THE PROPERTIES OF THE PROTEIN!

FUNCTIONAL GROUPS There are certain groups of atoms that are frequently attached to the organic molecules we will be studying, and these are called functional groups. These are things like hydroxyl groups which form alcohols, carbonyl groups which form aldehydes or ketones, carboxyl groups which form carboxylic acids, and amino groups which form amines.

Major Protein Functions Growth and repair Energy Buffer -- helps keep body pH constant

Dipeptide formed from two amino acid subunits Formed by the process of Dehydration Synthesis amino acid + amino acid ----- dipeptide + water

Hydrolysis of a dipeptide Breaking down of a dipeptide into amino acids dipeptide + H2O ---> aminoacid + amino acid

Polypeptide (protein) composed of three or more amino acids linked by synthesis reactions Examples of proteins include insulin, hemoglobin, and enzymes. ** There are an extremely large number of different proteins. The bases for variability include differences in the number, kinds and sequences of amino acids in the proteins