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