Biochemistry

The Chemistry of Life

Chemical Elements

• Elements: 105 single substances can’t be broken down.

• 4 Most Common Elements:• C- carbon• H- hydrogen• O- oxygen• N- nitrogen

Periodic Table Of Elements

Why Chemistry in Biology?

• Cells are involved in chemical reactions. Ex. H2O, O2, CO2, proteins.

• Elements alone are very lonely they join together (bond) to form compounds.

Types of Compounds

• Organic• Contain both C and H.• Living or once living

• Inorganic• Does not contain both C and H.• Non-living

Which are organic and which are inorganic?

• H2O• CO2

• C6H12O6

• C12H22O11

• NaCl

Remember: Water (H2O) is the most abundant

inorganic compound in the human body!

Four Types of Organic Compounds

• Carbohydrates: C, H, O

• Proteins: C, H, O, N

• Lipids: C, H, O

• Nucleic Acids: C, H, O, N, P

Carbohydrates:

• Contain C, H, O.• 2:1 ratio of H:O• Ex. C6H12O6, C12H22O11

• Ex. Sugars and starches• Names end in - ose. Ex. Glucose.• Function- quick energy (bread,

cereal, pasta, rice)

• One sugar- –Monosaccharide –Simple Sugar –glucose

• Two sugars- –Disaccharide –Double Sugar –maltose, lactose & sucrose

• Many sugars- –Polysaccharide –starch & cellulose

• Structure:Honey comb shape

Lipids/Fats

• Contain C, H, O• No 2:1 ratio of H & O.• Stored energy• Fats, oils, milk, butter.• Building blocks of a lipid: 3 Fatty

Acids and One Glycerol

Lipid

Nucleic Acids

• Contains C, H, O, N, P• Ex.’s: DNA and RNA (hereditary

material in the nucleus)• DNA: double stranded• RNA: single stranded

Structure of DNA

DNA:

Proteins• Contains C, H, O, N• Found in meat, fish, eggs, beans.• Function: builds and repairs cells (muscle

cells)• Building blocks are called amino acids

– 1 amino acid= peptide– 2 amino acids= dipeptide–Many amino acids= polypeptide

Ex) enzymes, insulin, hormones, hemoglobin.

• One amino acid:

Amino Acid

Polymer

• Chain of repeating units

Dehydration Synthesis- Make a polymer by removing

water.

Simple Complex

Carbohydrate-monosaccharide + monosaccharide disaccharide

+ water

Protein-amino acid + amino acid protein + water

peptide + peptide dipeptide + water

Lipid-3 Fatty Acids + 1 Glycerol Lipid(Fat) + water

Hydrolysis / Digestion: Break apart a polymer by adding water.

Complex Simple

Carbohydrate-Disaccharide + water monosaccharide +

monosaccharide

Protein-Protein + water amino acid + amino acid

Dipeptide + water peptide + peptide

Lipid-Lipid + water Glycerol + 3 fatty acids