Biology Fall 2014

Carbon is the main ingredient of organic molecules. a.k.a biomolecules

Composed of a backbone of carbon atoms bonded to one another

Carbon-based molecules are classified as organic molecules.

Inorganic molecules do not contain carbon skeletons

Hydrocarbons- molecules that contain only carbon and hydrogen

Functional group- group of atoms with a molecule that interacts in predictable ways with other molecules.

Hydrophilic- molecules that attract water molecules

Monomers- small molecular unit that is the building block of a larger molecule

Polymers- long chain of small molecular units called monomers All are built from fewer than 50 kinds of

monomers. Life’s large molecules are classified into 4

main categories: carbohydrates, lipids, proteins, and nucleic acids.

Dehydration reaction- a chemical reaction in which a water molecule is removed

Hydrolysis reaction- a chemical reaction in which a water molecule is added

Provide fuel & building material. Include starches & sugars. Used as an energy source. Carbohydrate- an organic compound

made up of sugar molecules

Sugars contain the elements carbon, hydrogen, and oxygen in a ratio of 1 carbon : 2 hydrogen : 1 oxygen

Simple sugars contain just one sugar unit

Ex: glucose, fructose, and galactose Sugar molecules, primarily glucose, are

the main fuel supply for cellular work. Cells use the carbon skeletons of these

as raw material for manufacturing other kinds of organic molecules.

Cells construct these using a hydrolysis reaction from two monosaccharides

Most common is sucrose

Long polymer chains made up of simple sugars monomers

Starch- a polysaccharide found in plant cells composed entirely of glucose monomers

Glycogen-polysaccharide in animal cells that consists of many glucose monomers

Cellulose- polysaccharide consisting of glucose monomers that reinforces plant-cell walls

Most animals including people cannot digest cellulose

Almost all carbohydrates are hydrophilic Water loving Most can be dissolved in water

A class of water avoiding molecules. Hydrophobic- water fearing Hydrophobia is important to the

function of lipids

Consists of a three-carbon backbone called glycerol attached to three fatty acids.

Solid at room temperature Cushion your organs Store energy for later use Provide your body with insulation

Saturated fat- fat in which all three fatty acid chains contain the maximum number of hydrogen atoms

Unsaturated fat- fat that contains less than the maximum number of hydrogen atoms in one or more of its fatty acid chains

Steroid- a lipid molecule in which the carbon skeleton forms four fused rings

Classified as lipids because they are hydrophobic, but are very different in function and structure.

Cholesterol- steroid molecule present in the plasma membranes of animal cells.

Proteins that speed up specific reactions in cells.

Activation energy- minimum amount of energy required to trigger a chemical reaction

Catalysts- compounds that speed up chemical reactions.

Substrate- specific reactant acted on by an enzyme

Active site- region of an enzyme into which a particular substrate fits