BIOCHEMISTRYBIOCHEMISTRY

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 And now for the Biochemistry portion of Biochemistry portion of

things….things….

CARBOHYDRATESCARBOHYDRATES

• Living things use carbohydrates as a key source Living things use carbohydrates as a key source of of ENERGYENERGY! !

• Plants use carbohydrates for structure Plants use carbohydrates for structure ((CELLULOSECELLULOSE) ) – include sugars and complex carbohydrates include sugars and complex carbohydrates

(starches) (starches) – contain the elements carbon, hydrogen, and oxygen contain the elements carbon, hydrogen, and oxygen

(the hydrogen is in a 2:1 ratio to oxygen) (the hydrogen is in a 2:1 ratio to oxygen)

Monosaccharides (simple sugars) Monosaccharides (simple sugars)

• all have the formula C6 H12 O6 all have the formula C6 H12 O6 • all have a single ring structure all have a single ring structure

– (glucose is an example) (glucose is an example)

Disaccharides (double sugars) Disaccharides (double sugars)

• all have the formula C12 H22 O11 all have the formula C12 H22 O11 • sucrose (table sugar) is an example sucrose (table sugar) is an example

Polysaccharides Polysaccharides

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

How are complex How are complex carbohydrates formed and carbohydrates formed and

broken down? broken down?

Dehydration Synthesis Dehydration Synthesis

• Combining simple molecules to form a more Combining simple molecules to form a more complex one with the complex one with the removal of waterremoval of water – ex. monosaccharide + monosaccharide ----> ex. monosaccharide + monosaccharide ---->

disaccharide + waterdisaccharide + water– (C6H12O6 + C6H12O6 ----> C12H22O11 + H2O(C6H12O6 + C6H12O6 ----> C12H22O11 + H2O

• Polysaccharides are formed from repeated Polysaccharides are formed from repeated dehydration syntheses of water dehydration syntheses of water – They are the stored extra sugars known as starchThey are the stored extra sugars known as starch

Hydrolysis Hydrolysis

• Addition of Addition of WATERWATER to a compound to to a compound to SPLITSPLIT it into smaller subunits it into smaller subunits – (also called chemical digestion) (also called chemical digestion) – ex. disaccharide + H2O ---> ex. disaccharide + H2O --->

monosaccharide + monosaccharidemonosaccharide + monosaccharide

C12 H22 O11 + H2 O ---> C6 H12 O6 + C6 H12 O6C12 H22 O11 + H2 O ---> C6 H12 O6 + C6 H12 O6

Lipids (Fats)Lipids (Fats)• Fats, oils, waxes, steroids Fats, oils, waxes, steroids • Chiefly function in Chiefly function in energy storage, protection, energy storage, protection,

and insulation and insulation • Contain carbon, hydrogen, and oxygen but the Contain carbon, hydrogen, and oxygen but the

H:O is not in a 2:1 ratio H:O is not in a 2:1 ratio • Tend to be Tend to be largelarge molecules -- an example of a molecules -- an example of a

neutral lipid is below neutral lipid is below

• Neutral lipids are formed from the union of Neutral lipids are formed from the union of one one glycerol molecule and 3 fatty acids glycerol molecule and 3 fatty acids

• 3 fatty acids + glycerol ----> neutral fat (lipid) 3 fatty acids + glycerol ----> neutral fat (lipid) • Fats -- found chiefly in Fats -- found chiefly in animalsanimals • Oils and waxes -- found chiefly in Oils and waxes -- found chiefly in plantsplants • Oils are liquid at room temperature, waxes are Oils are liquid at room temperature, waxes are

solids solids • Lipids along with proteins are key components of Lipids along with proteins are key components of

cell membranescell membranes • Steroids are special lipids used to build many Steroids are special lipids used to build many

reproductive hormones and cholesterolreproductive hormones and cholesterol

PROTEINSPROTEINS

• contain the elements carbon, hydrogen, oxygen, contain the elements carbon, hydrogen, oxygen, and nitrogen and nitrogen

• composed of MANY amino acid subunitscomposed of MANY amino acid subunits• It is the arrangement of the amino acid that It is the arrangement of the amino acid that

forms the primary structure of proteins. forms the primary structure of proteins. • The basic amino acid form has a The basic amino acid form has a carboxyl carboxyl

groupgroup on one end, a on one end, a methyl groupmethyl group that only that only has one hydrogen in the middle, and a has one hydrogen in the middle, and a amino amino groupgroup on the other end. on the other end.

• Attached to the methyl group is a Attached to the methyl group is a RR groupgroup. .

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

FUNCTIONAL GROUPSFUNCTIONAL GROUPS

• There are certain groups of atoms that are There are certain groups of atoms that are frequently attached to the organic molecules we frequently attached to the organic molecules we will be studying, and these are called will be studying, and these are called functional functional groupsgroups. .

• These are things like These are things like hydroxyl groupshydroxyl groups which which form form alcoholsalcohols, , carbonyl groupscarbonyl groups which form which form aldehydesaldehydes or or ketonesketones, , carboxyl groupscarboxyl groups which which form form carboxylic acidscarboxylic acids, and , and amino groupsamino groups which form which form aminesamines. .

Major Protein Functions Major Protein Functions

• Growth and repair Growth and repair • Energy Energy • Buffer -- helps keep body pH constant Buffer -- helps keep body pH constant

Dipeptide Dipeptide

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

Hydrolysis of a dipeptide Hydrolysis of a dipeptide

• Breaking down of a dipeptide into amino acidsBreaking down of a dipeptide into amino acids• dipeptide + H2O ---> aminoacid + amino aciddipeptide + H2O ---> aminoacid + amino acid

Polypeptide (protein) Polypeptide (protein)

• composed of composed of three or morethree or more amino acids linked amino acids linked by synthesis reactions by synthesis reactions

• Examples of proteins include Examples of proteins include insulin, insulin, hemoglobin, and enzymes. hemoglobin, and enzymes.

• ** There are an extremely large number of ** There are an extremely large number of different proteins. different proteins.

• The bases for variability include differences in The bases for variability include differences in the number, kinds and sequences of amino the number, kinds and sequences of amino acids in the proteins acids in the proteins