Organic Compounds: Biomolecules

I. Chemistry of Carbon • A. Carbon has 4 valence e-• B. Carbon can form 4 strong covalent bonds with

atoms such as H, O, P, S & N• C. Carbon has a very wide versatility since it can

bond with other Carbon atoms, all compounds with carbon are said to be organic compounds.

II. Macromolecules• A. Macromolecules: molecules that are made from

several smaller molecules i.e. “giant molecule”• B. Macromolecules are formed by the process of

polymerization– Monomers: 1 small unit– Polymers: more than 1 small unit

III. Groups of Biomolecules• A all living things are made up of 4 organic

compounds:– Carbohydrates– Lipids– Nucleic acids– Proteins

IV. Carbohydrates• A. Compounds made up of carbon, hydrogen, and

oxygen usually in the ratio of 1:2:1 (CnH2nOn)

• B. These compounds are mainly used for energy in animals and structural support for plants

• C. Main structure unit is monosaccharide• D. Complex structure is starch or polysaccharide – ex. Pasta, Potato

IV. Carbohydrates• E. Monosaccharide: single sugar molecules– Glucose– Fructose (found in fruit)– Galactose (found in milk)

• F. Disaccharide: 2 monosaccharides– Lactose (glucose+ galactose)– Maltose (glucose + glucose)– Sucrose (glucose + frutose)

• G. Polysaccharide: many monosaccharides– Glycogen (stored in our liver)– Cellulose ( plant starch for structure (β-glucose))– Starch (plant storage (α-glucose))

•

IV. Carbohydrates• H. Creating large sugar molecules you will remove a

-H atom from one sugar molecule and a –OH group from another; this is called dehydration synthesis (since you are literally removing water from the molecules).– 1. This creates a glycosidic bond

• I. The opposite of this formation would be breaking down glucose by adding water or hydrolysis.

V. Lipids• A. Compounds made mostly of carbon and

hydrogen and are insoluble in water• B. Used to store energy and are important parts of

biological membranes & insulation • C. Main structure: Glycerol combined with 3 fatty

acid chains (long chain of C and H)

• 1. Structure of a lipid: – Each carboxyl group (-COOH) of the 3 fatty acids must

react with one of the 3 hydroxyl groups (-OH) from the glycerol molecule, this occurs with the removal of water

What is this called again???– The linkage between the glycerol & fatty acid chain is

called an ester linkage

V. Lipids

• D. 2 groups of Lipids:– Saturated: only single bonds between carbon• Solid at room temperature

– Unsaturated: at least one double bond between carbon• Liquid at room temperature• Polyunsaturated: many double bonds

• E. Lipids are categorized into fats, oils, phospholipids & steroids

• Steroids

• Phospholipids – More on this later

VI. Nucleic Acids

• A. Macromolecules containing hydrogen, oxygen, nitrogen, carbon and phosphorous

• B. Nucleic acids store and transmit genetic information– Two kinds: DNA & RNA

• C. Main structure: Nucleotides (monomer)

What is that?!?!?

• D. Nucleotides are composed of 3 parts– 5-carbon sugar– Phosphate group– Nitrogenous base

VII. Proteins• A. Macromolecules composed of nitrogen, carbon,

hydrogen and oxygen.• B. Proteins control rate of reactions and regulate

cell processes. Some used to form bones and muscles, others transport material and still others are responsible for growth & repair. – 1. Most proteins act as enzymes which speed up

reactions by lowering the activation energy.

• C. Main structure unit (monomer): amino acid– Structure that is composed of an

amino group (-NH₂) one carboxyl group (-COOH), a hydrogen and a –R group

– The –R group is the only thing that changes between amino acids

• D. More than 20 different amino acids are found in nature– The sequence when amino acids join

together determine the function of the protein

– Joining them together is called a polypeptide, the bond is a peptide bond

VIII. Functional GroupsFunctional Group Structural Formula Molecular Formula

Amino -NH2

Alkyl -CnH2n+1

Methyl -CH3

Ethyl -C2H5

Propyl -C3H7

Carboxyl -COOH

Hydroxyl -OH

Aldehyde -CHO

Keto (carbonyl) -CO

Sulfhydryl -SH

Phenyl -C6H5

Phosphate -PO4

• E. 4 levels of organization:– 1st: sequence of amino

acids– 2nd: twisting of chain due

to hydrogen bonds(alpha helix or beta pleated sheets)

– 3rd: folding of the chain on itself

– 4th: arrangement in space

IIX. Regulation of Enzyme Activity

• A. All Enzymes:– 1. Fit one specific type of substrate (think lock and key)– 2. Work best around normal human body temperature– 3. Can be influenced by a change in pH– 4. Increase activity with increasing amounts of substrate