Biology Chapter 3 Notes

Organic Chemistry

The study of compounds that contain carbon regardless of origin.

Carbon

An element that has 4 electrons in its outer shell, enabling it to form up to four bonds.

Covalent Bonds

Bonds formed when carbon only shares electrons to connect with other atoms.

Hydrocarbons

Organic molecules consisting of only carbon and hydrogen.

Functional Groups

Components of organic molecules commonly involved in chemical reactions.

Structural Isomers

Compounds with the same molecular formula but different covalent arrangements of their atoms.

Cis-trans Isomers (Geometric Isomers)

Isomers that have the same covalent bonds but differ in their spatial arrangements.

Enantiomers

Isomers that are mirror images of each other.

Macromolecules

Large polymers known for their huge size.

Dehydration Reaction

A reaction where two monomers bond together through the loss of a water molecule.

Hydrolysis

The process where polymers are disassembled into monomers, essentially the reverse of dehydration.

Monosaccharides

The simplest sugars, which serve as a major fuel for cells.

Disaccharides

Composed of two monosaccharides joined by a glycosidic bond.

Polysaccharides

Many monosaccharides linked in long polymers, used for energy storage or structural purposes.

Starch

Storage polysaccharide of plants, composed of glucose monomers.

Glycogen

Storage polysaccharide in animals, mainly stored in liver and muscle cells.

Cellulose

Structural polysaccharide of plants, composed of long chains of glucose monomers.

Nucleic Acids

Responsible for the storage, expression, and transmission of genetic information.

DNA

Deoxyribonucleic acid; stores genetic information encoded in the sequence of nucleotide monomers.

RNA

Ribonucleic acid; decodes DNA into instructions for forming polypeptides.

Amino Acids

Building blocks of proteins; 20 different amino acids are used to form proteins.

Polypeptides

Polymers of amino acids formed by dehydration reactions.

Protein Structure

Determined by the sequence of the amino acids in a polypeptide and critical for its function.

Primary Structure

The unique sequence of amino acids in a protein.

Secondary Structure

Consists of coils and folds in the polypeptide chain, including a-helices and B-pleated sheets.

Tertiary Structure

Determined by interactions among various side chains (R-groups) in a polypeptide.

Quaternary Structure

Results when a protein consists of multiple polypeptide chains.

Lipids

Composed predominantly of hydrogen and carbon atoms; nonpolar and insoluble in water.

Fats

Known as triglycerides, formed by bonding glycerol to 3 fatty acids.

Saturated Fatty Acids

Fatty acids where all carbons are linked by single bonds, solid at room temperature.

Unsaturated Fatty Acids

Fatty acids that contain one or more double bonds, liquid at room temperature.

Phospholipids

Molecules formed from glycerol, two fatty acids, and a phosphate group, amphipathic in nature.

Steroids

Lipids composed of four interconnected rings of carbon atoms, insoluble in water.