Biology - Chapter 3: The Chemical Basis of Life II - Organic Molecules

Flashcards for reviewing Biology lecture notes on organic molecules and the chemical basis of life.

Organic Molecules

Molecules that contain carbon (C) and hydrogen (H) and are mainly abundant in living organisms.

Macromolecules

Large, complex organic molecules including carbohydrates, lipids, proteins, and nucleic acids.

Inorganic Molecules

Usually contains positive and negative ions and ionic bonding, often associated with non-living matter.

Macromolecules

Carbohydrates, lipids, proteins, and nucleic acids due to their large size.

Polymers

Made up of monomers.

Dehydration

Removal of a water molecule during polymer formation.

Hydrolysis

Addition of a water molecule during polymer degradation.

Carbohydrates

An immediate energy source in living organisms, composed of C, H, and O atoms with the general formula Cn(H2O)n.

Monosaccharides

Simplest sugars that provide ready energy and are soluble in water due to hydroxyl groups.

Structural Isomers

Glucose and galactose.

Stereoisomers (Geometric isomers)

α- and β-glucose.

Enantiomers

D- and L-glucose.

Disaccharides

Composed of 2 monosaccharides joined by dehydration and broken apart by hydrolysis, examples include sucrose, maltose, and lactose.

Polysaccharides

Many monosaccharides linked together to form long polymers for short term energy storage.

Starch

Is a mixture of amylose and amylopectin, both of which are polymers of glucose, and used by plants as a way to store excess glucose.

Glycogen

Animals store glucose as this (granules in liver), polysaccharide of glucose which functions as the primary short term energy storage in animal cells.

Cellulose

Most abundant carbohydrate; a polymer of β-glucose found in plant cell walls.

Chitin

Forms the external skeleton of many insects and the cell wall of fungi.

Glycosaminoglycans

Found in animals; abundantly found in cartilage; tend to have sugar monomers with carboxyl and sulfate groups.

Lipids

Organic molecules composed predominantly of H and C atoms, nonpolar, and very insoluble in water, used for insulation and long-term energy storage.

Fats

Mixture of triglycerides formed by bonding glycerol to three fatty acids.

Glycerol

Compound with three OH groups (OH is polar group- glycerol soluble in water).

Fatty acid

Consists of long hydrocarbon (R) chain with a carboxyl (-COOH) group at one end.

Saturated Fatty Acids

Have no double bonds between the carbon atoms and tend to be solid at room temperature.

Unsaturated Fatty Acids

Contain one or more double bonds in the carbon chain and tend to be liquids at room temperature.

Phospholipids

Membrane components containing a polar phosphate group and hydrophobic fatty acid tails; form a phospholipid bilayer in cell membranes.

Steroids

Have skeletons of 4 interconnected carbon rings and are usually not very water-soluble; include cholesterol, estrogen, and testosterone.

Waxes

Long-chain fatty acid bonds with a long-chain alcohol, secreted onto plant leaves and insect cuticles; provide a barrier to water loss.

Proteins

Diverse functions including support, enzymatic activity, transport, defense, hormones, and motion; composed of C, H, O, N, and S.

Amino acids

Are the monomers of proteins.

Peptide

Two or more amino acids bonded together.

Polypeptide

Chain of many amino acids joined by peptide bonds.

Primary Protein Structure

Sequence of amino acids.

Secondary Protein Structure

Polypeptide coils or folds in a particular fashion, often held by hydrogen bonding.

Tertiary Protein Structure

Folding and twisting that results in final three-dimensional shape of a polypeptide.

Quaternary Protein Structure

Consists of more than one polypeptide.

Nucleic Acids

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

Deoxyribonucleic acid (DNA)

Store genetic information coded in the sequence of their monomer building blocks.

Ribonucleic acid (RNA)

Involved in decoding genetic information into instructions for linking together a specific sequence of amino acids to form a polypeptide chain

Monomer is a nucleotide

Made up of a phosphate group, a 5C sugar (either ribose or deoxyribose), and a single or double ring of C and N atoms known as a base

DNA

Deoxyribose, Thymine (T), 2 strands- double helix, 1 form

RNA

Ribose, Uracil (U), Single strand, Several forms