Chapter 3: The Chemistry of Organic Molecules

Organic Molecules

always contain carbon and hydrogen,

always bonded covalently,

usually associated with living organisms

and are often quite large

inorganic molecules

molecules that do not contain carbon,

usually bonded ionically,

often associated with non living things

and always contain small amounts of atoms

4 types of biomolecules

carbohydrates, lipids, proteins, nucleic acids

structural carbohydrates

Both polymers of glucose, Cellulose in plant cell walls, Chitin in the cell walls of fungi and crustaceans, and peptidoglycan found in bacterial cell walls\

carbon atoms

6 atoms, 4 electrons on the outer ring, can bond with up to four other atoms often with other carbons

carbon skeleton

The chain of carbon atoms that forms the structural backbone of an organic molecule. This also determines the shape

functional groups

cluster of specific atoms that always react in the same way

Hydrophillic (polar)

soluble in water, likes it

hydrophobic, polar

insoluble in water, hates it

Isomers

Two different molecules that have the same chemical formula

Monomer

one subunit

Polymer

many monomers linked together

monomer of proteins

amino acids

monomer of carbohydrates

monosaccharides

monomer of lipids

glycerol and fatty acids

monomer of nucleic acids

nucleotides

dehydration reaction

A chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule.

examples of dehydration synthesis

monosaccharides to disaccharides. amino acids joining via peptide bonds

Hydrolysis

the chemical breakdown of a compound due to reaction with the addition of water.

example of hydrolosis

digestion of starch into glucose monomers

Monosaccharides

Single sugar molecules

glucose, fructose, galactose, ribose, and deoxyribose

have a backbone of 3-7 carbons

Disaccharide

A double sugar, consisting of two monosaccharides joined by dehydration synthesis.

Lactose= Galactose+Glucose

Sucrose(table sugar)= Glucose+fructose

Maltose=Glucose+Glucose

Polyssacharides

multiple sugars

1. Cellulose - in plants'

2. Chitin - in animals and fungi

3. Peptidoglycan - in bacteria

storage polysaccharides

starch (plants) used for short term energy storage, and glycogen (animals) found in the liver

Lipids

Energy-rich organic compounds, such as fats, oils, and phospholipids, that are made of carbon, hydrogen, and oxygen. nothing about them likes water

hydrocarbon

large nonpolar molecules

insoluble in water

Triglycerides

a long- term energy storage made up of a single molecule of glycerol and three molecules of fatty acid.

saturated fatty acid

no double bonds between carbon atoms

unsaturated fatty acid

1 or more double bond between carbons

Phospholipids (membrane components)

a lipid consisting of a glycerol bound to two fatty acids and a phosphate group. Heads are hydrophillic and tails are hydrophobic

proteins

extremely important to structure and function of cells

polymers of aa

polypeptide that has been folded into
a particular shape and has function

functions of proteins

structural support, enzymes, nutrient transport, defense, regulation, motion

How many amino acids are there that make up proteins?

20

How do amino acids differ?

have different R groups e.g. glycine has a hydrogen in its R group - simplest amino acid

peptide bond

The chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid

Dipeptide

Two amino acids bonded together

tripeptide

3 amino acids

Polypeptide

long chain of amino acids that makes proteins

How many polypeptide chains make up a protein?

Any amount

protein structure

must have correct shape to function
properly

native conformation

correct 3D shape; Held together with many hydrogen bonds (and maybe
some ionic and covalent bonds, too)

denatured

protein has lost its natural shape
Denatured proteins are not functional

main types of nucleic acids

DNA and RNA

Deoxtribonucleic acid (DNA)

stores genetic information, located in chromosomes and the nucleus

Robonucleic Acid (RNA)

serves primarily in assembly of proteins, found in nucleus, and cytoplasm

components of a nucleotide

nitrogenous base, phosphate, pentose sugar

Pyrimadine bases

cytosine, thymine, uracil “CUT” (i could could my finger on the pyramid)

Purine bases

Adenine and Guanine

how do nucleotides join?

Covalent bonds btw the phosphate group on one and the ribose (sugar) of another.

DNA vs RNA structure

DNA: Double helix, adednine-thymine and guanine-cytosine

sugar is deocyribose

RNA: Single strand, Adenine-uracil and Guanine-cytosine. sugar is ribose

5’ - phosphate hanging off

3’ - no phosphate hanging off

ATP (adenosine triphosphate)

high-energy molecule

last 2 phosphate bonds unstable, easily broken (negatively charged, don’t like each other)

hydrolysis releases energy → used by cell for many things

organic molecules

Carbon-based molecules

carbohydrate

A simple or complex compound composed of carbon, oxygen and hydrogen.

monosaccharide

monomer of carbohydrate, A single sugar molecule such as glucose or fructose, the simplest type of sugar.

polysaccharide

Carbohydrates that are made up of more than two monosaccharides, polymer, aka complex carbohydrate

glucose

monomer, A simple sugar (monosaccharide) that is an important source of energy.

lipid

Fats, oils, and phospholipids, they are energy-rich organic compounds

amino acid

monomer of proteins

protein

Chains of amino acids.

nucleotide

monomer of nucleic acid, A building block of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.