Biochemistry The Chemistry of Life

Mark Robertson Professor of Biology

Delta College

The Chemistry of Carbon■ Molecules are either organic (contain

carbon) or inorganic (carbon is absent). ■ Organics contain carbon chains with

single, double, or triple-bonds.

C C C CC C

Common Organic Molecules■ Use monomers to produce polymers

(usually by dehydration synthesis). ■ Four major macromolecules:

– Carbohydrates (from monosaccharides) – Lipids (from fatty acids) – Proteins (from amino acids) – Nucleic Acids (from nucleotides)

Carbohydrates■ Made of chains or rings of

carbon with hydrogen and oxygen attached, their name ends in -ose

■ Monosaccharides (1 sugar) – 1) Glucose (C6H12O6) powdered

sugar – 2) Galactose (C6H12O6) – 3) Fructose (C6H12O6) plant sugar

(1)

(2)

(3)

Carbohydrates■ Disaccharides (consist of 2

linked monosaccharides) – 4) Sucrose (C12H22O11)

table sugar – 5) Lactose (C12H22O11)

milk sugar)

(4)

(5)

Carbohydrates■ Storage Polysaccharides

– Starch (plants) – Glycogen (liver of animals)

Glycogen

Metabolizing Saccharides

Lipids■ Generally large, nonpolar

(few charged ends), and hydrophobic (water fearing)

■ Contain long chains of carbon and hydrogen, but very little oxygen (-CH2CH2CH2-)

■ Grouped into fats, oils, steroids, phospholipids, and waxes

Lipids - Fatty Acids■ Many fats are used for energy storage and

based on glycerol backbone ■ Can attach fatty acids

-H

-HHO-

H2O H2O

What type of reaction was this? (note: water was released)

Lipids - Human Blood■ If no double bonds, saturated fat

(animal fats like lard and chicken fat) ■ Double bonds means unsaturated

(plant fats like olive oil and peanut oil) ■ Use triglycerides

to move fats in our blood

Triglyceride

Lipids - Phospholipids■ If take a glyceride molecule and add

2 fatty acids and a phosphate group, get a phospholipid (used in cell membranes)

■ Phosphate attracts water and the fatty acids repel water

Proteins - Amino Acids

■ Made from linked amino acids (with 20 used in organisms)

■ 10 essential amino acids ■ Functional vs. Structural uses

20 DifferentFunctional

Groups (-R)

CarboxylicAcid Group

(-COOH)

AminoGroup(-NH2)

AsparticAcid

Cysteine Glycine

Proteins - Forming Chains

■ Linkages are called peptide bonds ■ Dehydration synthesis forms links ■ Resulting molecule is called a polypeptide

+

PeptideBond

Proteins - Structural Levels■ Primary Structure

– Order of the Amino Acids ■ Secondary Structure

– Helix or sheet-like folding ■ Tertiary Structure

– 3-D folding to create shapes ■ Quaternary Structure

– Interaction of 2 or more chains

Nucleic Acids (DNA/RNA)

■ Built from nucleotides which have a sugar (ribose or deoxyribose), a phosphate group, and 1 of 5 bases – Thymine (T) – Adenine (A) – Cytosine (C) – Guanine (G) – Uracil (U)

- D - P - D - P - D - P - D - P -

- D - P - D - P - D - P - D - P -

B B B B B B B B~ ~ ~ ~

One Nucleotide

Potential Journal Critique Topics

■ Carbohydrate Disorders? ■ Protein Deficiency Disorders? ■ Lipid Disorders? ■ Amino Acid Disorders (like PKU)? ■ Body Builder (High Protein) Diets? ■ Disorders due to Improper Protein

Shapes (Amyloid Proteins)?