Biology Vocab Terms 2b-3a Flashcards
Acid
A substance that increases the hydrogen ion concentration in a solution
Base
A substance that decreases the hydrogen ion concentration in a solution
Buffer
A chemical substance that minimizes changes in pH by accepting hydrogen ions from or donating hydrogen ions to solutions
Chemical Reaction
The making and breaking of chemical bonds, leading to changes in the composition of matter
Cohesion
The sticking together of molecules of the same kind, often by hydrogen bonds
Heat
Thermal energy in transfer from one body of matter to another
pH scale
A measure of the acidity of a solution, ranging in value from 0 (most acidic) to 14 (most basic). The letters pH stand for potential hydrogen and refer to the concentration of hydrogen ions
Product
An ending material in a chemical reaction
Reactants
A starting material in a chemical reaction
Solute
A substance that is dissolved in a solution
Solution
A liquid that is a homogeneous mixture of two or more substances
Surface Tension
A measure of how difficult it is to stretch or break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules
Temperature
A measure in degrees of the average thermal energy of the atoms and molecules in a body of matter
Carbohydrate
Member of the class of biological molecules consisting of single monomer sugars, two monomer sugars, and polymers
Carbon Skeleton
The backbones of organic molecules
Cellulose
A structural polysaccharide of plant cell walls composed of glucose monomers. Cellulose molecules are linked by hydrogen bonds into cable like fibrils
Chitin
A structural polysaccharide found in many fungal cell walls and in the exoskeletons of arthropods
Dehydration Reaction
A chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule
Disaccharide
A sugar molecule consisting of two monosaccharides linked by a dehydration reaction
Enzyme
A macromolecule, usually a protein, that serves as a biological catalyst, changing the rate of a chemical reaction without being consumed by the reaction
Fat
A lipid composed of three fatty acids linked to one glycerol molecule; a triglyceride. Most fats function as energy storage molecules
Functional Group
A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and involved in chemical reactions.
Glycogen
An extensively branched glucose storage polysaccaride found in liver and muscle cells; the animal equivalent of starch
Hydrocarbon
An organic compound composed only of the elements carbon and hydrogen
Hydrolysis
A chemical reaction that breaks bonds between two molecules by the addition of water; process by which polymers are broken down and an essential process of digestion
Hydrophilic
“Water loving”; pertaining to polar or charged molecules (or parts of molecules) that are soluble in water
Hydrophobic
“Water fearing”; pertaining to nonpolar molecules (or parts of molecules) that do not dissolve in water
Lipid
An organic compound consisting mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds, making the compound mostly hydrophobic. Lipids include fats, phospholipids, and steroids that are insoluble in water
Macromolecule
A giant molecule formed by the joining of smaller molecules, usually by a dehydration reaction
Monomer
The subunit that serves as a building block of a polymer
Monosaccharide
The simplest carbohydrate; a simple sugar with a molecular formula that is generally some of multiple CH20. Monosaccharides are the monomers of disaccharides and polysaccharides
Organic Compound
A chemical compound containing the element carbon and usually the element hydrogen
Phospholipid
A lipid made up of glycerol joined to two fatty acids and a phosphate group, giving the molecule two non-polar hydrophobic tails and a polar hydrophilic head. Phospholipids form bilayers that function as biological membranes
Polymer
A large molecule consisting of many identical or similar monmers linked together by covalent bonds
Polysaccharide
A carbohydrate polymer of many monosaccharides (sugars) linked by dehydration reactions.
Saturated
(of an organic molecule) containing the greatest possible number of hydrogen atoms, and so having no carbon–carbon double or triple bonds
Starch
A storage polysaccharide in plants; a polymer of glucose
Unsaturated
(of organic molecules) having carbon–carbon double or triple bonds and therefore not containing the greatest possible number of hydrogen atoms for the number of carbons.
denoting fats containing a high proportion of fatty acid molecules with at least one double bond, considered to be healthier in the diet than saturated fats.
