Unit One Flashcards
Hydrogen bonds
Bonds between hydrogen and f/o/n of another molecule, strongest intermolecular force but weaker than intramolecular forces, give water its special properties
Bonds between different water molecules
Polar covalent bonds
When atoms of a molecule have an unequal sharing of electrons resulting in partial negative and partial positive charges
Bonds between hydrogen and oxygen of water molecules
Polarity
Unequal distribution of electrons resulting in partial positive and partial negative charges
Hydrophilic
Water loving, soluble in water, because soluble in water usually means polar
Hydrophobic
Insoluble in water, nonpolar generally because water dissolves polar things
Cohesion
The tendency of molecules to stick together, forces of attraction between molecules of the same substance
Adhesion
The clinging of one substance to another, forces of attraction between molecules of different substances
Surface tension
A measure of how difficult it is to stretch or break the surface of a liquid, how much energy it requires to expand the surface area of a liquid
Heat storage capacity
Heat is the a,punt of energy associated with the movement of atoms and molecules in a body of matter
Temperature is the intensity of heat aka the average speed of molecules rather than the total amount of heat energy
Heat storage capacity is how much heat can be absorbed without the molecule breaking apart aka basically specific heat
pH
pH stands for the potential of hydrogen, the pH scale describes how acidic or basic a solution is, 0 is most acidic, 7 is neutral, 14 is most basic, each increase by one in the scale means a decrease by the power of ten in the acidity
Acid
A compound that donates hydrogen ions to solutions, ex. HCl, acidic solutions have higher concentrations of H+ than OH-
Base
A compound that accepts hydrogen ions and removed them from solution ex. NaOH, have a higher OH- concentration than H+, basic solutions are also called alkaline
Buffer
Stabilizes the pH, minimizes changes in pH, both an H+ acceptor and donor, important in our blood because they keep it at the right pH so we don’t die.
Organic compounds
Carbon-based molecules
Isomers
Compounds with the same formula but different structures
Functional group
The first five chemical groups important in the chemistry of life, they affect a molecule’s function by participating in chemical reactions in characteristic ways, they are polar and hydrophilic, large role in water-based life
Carboxyl group
Consists of carbon double bonded to an oxygen and also bonded to a hydroxyl group. Acts as an acid by contributing an H+ to a solution and becoming ionized. Compounds with carboxyl groups are called carboxylic acids
Dehydration synthesis
Cells link monomers together to form polymers by dehydration synthesis. The reaction removes a molecule of water and combines two monomers. H+ and OH- combine and form water, covalent bond forms between the monomers too.
Hydrolysis
The reverse of dehydration synthesis, cells break bonds between monomers by adding water to them, monomers absorb water and break apart
Carbohydrates
A class of molecules ranging from the small sugar molecules dissolved in soft drinks to large polysaccharides like the swerve molecules we consume in pasta and potatoes
One monomer looks like a hexagon
Monosaccharides make up polysaccharides
Almost all are hydrophilic because of the many hydroxyl groups attached to their sugar monomers
Functions of carbohydrates
Energy source
Structure (mostly for plants)
Monosaccharides give energy
Polysaccharides store energy (starch in plants, glycogen in animals) and give structure (cellulose in plants)
Monosaccharides
The carbohydrate monomers, single unit sugars. Can be hooked together by dehydration synthesis to form more complex sugars and polysaccharides, generally have molecular formulas that are some multiple of CH2O.
Main fuel molecules for cellular work, their carbon skeletons are used as raw material for making other kinds of organic molecules
Disaccharides
Cells make disaccharides from two monosaccharides by dehydration synthesis, most common disaccharide is sucrose
Polysaccharides
Polymers of monosaccharides linked together by dehydration synthesis. May function as storage molecules or as structural compounds.
Macromolecules
Four main classes of large biological molecules are carbohydrates, lipids, proteins, and nucleic acids, on a molecular scale many of these are gigantic so they’re called macromolecules
Polymers
Cells make most of their large molecules by joining smaller molecules into chains called polymers. Long molecules consisting of many identical or similar building blocks strung together.
Monomers
Building blocks of polymers
Glycogen
A glucose polysaccharide, animals store excess sugar in the form of glycogen, more highly branched than starch, most of ours is stored in the liver and muscle, release glucose when needed
Starch
Storage polysaccharide in plants, consists entirely of glucose monomers. Coil into a helical shape, starch helix can be unbranded or branched, plants and animals need sugar for energy and as raw material for building other molecules, plant cells often contain starch granules from which they can withdraw glucose by hydrolysis
Cellulose
The most abundant organic compound on earth, forms cable like fibrils in the tough walls that enclose plant cells. Polymers of glucose, but glucose monomers linked together in a different orientation. Joined by hydrogen bonds, strong. Not a nutrient for humans, but helps digestive system health. Fiber.
Chitin
Structural polysaccharide, used by insects and crustaceans to build their exoskeleton, also found in the cell walls of fungi, humans use chitin to make a strong and flexible surgical thread that decomposes after a wound or incision heals
Lipids
Diverse compounds that are grouped together because they mix poorly, if at all, with water. Consist mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds. Hydrophobic.
Fat
A large lipid made from two kinds of smaller molecules:glycerol and fatty acids
