Organic chemistry
the study of all compounds that contain bonds between carbon atoms
Carbon
Four valence electrons (each electron can join with an electron from another atom to form a strong covalent bond) Can bond with many elements (hydrogen, oxygen, phosphorus, sulfur, and nitrogen) Carbon atom can bond to another carbon atom (can form chains that are almost unlimited in length, carbon-carbon bonds can be single, double, or triple covalent bonds) No other element comes close to matching carbon's versatility
Macromolecules
giant molecules"Formed by a process known as polymerization (larger compounds are built by joining small ones together) Monomers (the smaller units) join together to form polymers. Monomers in a polymer may be identical or different
Organic compounds
classified into four groupsCarbohydratesLipidsNucleic acidsProteins
Carbohydrates
Carbon, hydrogen, and oxygen atoms (1:2:1 ratio) Functions: Living things use carbohydrates as their main source of energy Plants and some animals also use carbohydrates for structural purposes Examples: starch, cellulose Monomer units: Monosaccharaides: single sugar molecules (glucose, fructose)Polysaccharides: large macromolecules formed from monosaccharaides (glycogen [animal starch], cellulose [plant starch])
Lipids
Carbon and hydrogen atoms Functions: Lipids can be used to store energy Some lipids are important parts of biological membranes and waterproof coverings Steroids are lipids as well Examples: fats, oils, waxes, steroids Many lipids are formed when a glycerol molecule combines with compounds called fatty acids Saturated: if each carbon atom in a lipid's fatty acid chains is joined to another carbon atom by a single bond (the fatty acid contains the maximum possible number of hydrogen atoms) Unsaturated: if there is at least one carbon-carbon double bond in a fatty acid Polyunsaturated: lipids whose fatty acids contain more than one double bond Monomer units: fatty acid chains
Nucleic Acids
Hydrogen, oxygen, nitrogen, carbon, and phosphorus (PONCH) Functions: Nucleic acids store and transmit hereditary, or genetic, information Monomer units: Nucleotides: consist of three parts: a 5-carbon sugar, a phosphate group, and a nitrogenous base Individual nucleotides can be joined by covalent bonds to form a polynucleotide, or nucleic acid Examples: Ribonucleic acid (RNA): contains the sugar ribose Deoxyribonucleic acid (DNA): contain the sugar deoxribose DIAGRAM
Proteins
Nitrogen, carbon, hydrogen, oxygen (NOCH) Functions: Some proteins control the rate of reactions and regulate cell processes Some are used to form bones and muscles Others transport substances into or out of cells or help to fight disease Monomer units: Amino acids: compounds with an amino group (-NH2) on one end and a carboxyl group (-COOH) on the other end The portion of each amino acid that is different is a side chain called an R-group Proteins are among the most diverse macromolecules: more than 20 different amino acids are found in nature Four levels of organization: 1. The sequence of amino acids in a protein chain 2. The amino acids within a chain can be twisted or folded 3. The chain itself is folded 4. If a protein has more than one chain, each chain has a specific arrangement in space Van der Waals forces and hydrogen bonds help maintain a protein's shape Examples: antibodies, muscle tissue
Biology
Science that seeks to understand the living world
Cell
Collection of living matter enclosed by a barrier that separates the cell from its surroundings, basic unit of all forms of life
Sexual reproduction
Process by which cells from two different parents unite to produce the first cell of a new organism
Asexual reproduction
Process by which a single parent reproduces by itself
Metabolism
Set of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes
Homeostasis
Process by which organisms maintain a relatively stable internal environment
Evolution
Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms
Biosphere
Part of Earth in which life exists including land, water, and air or atmosphere
Ecosystem
Collection of all the organisms that live in a particular place, together with their nonliving environment
Community
Assemblage of different populations that live together in a defined area
Population
Group of individuals of the same species that live in the same area
Organism
Individual living thing
Molecule
Smallest unit of most compounds, structure that results when atoms are joined together by covalent bonds
Atom
Basic unit of matter
Nucleus:
The center of the atom which contains the protons and neutrons; in cells, the structure that contains the cell's genetic material (DNA) and controls the cell's activities
Proton:
Positively charged particles, in nucleus same mass as neutrons, atomic number
Neutron:
No charge, in nucleus
Electron
Negatively charged particle; located outside the atomic nucleus
Valence electrons
Electrons available to form bonds
Ion
positively and negatively charged atoms
Element
Substance consisting entirely of one type of atom
Isotope
Atom of an element that has a number of neutrons different from that of other atoms of the same element
Compound
Substance forced by the chemical combination of two or more elements in definite proportions
Ionic bond
Bond formed when one or more electrons are transferred from one atom to another
Covalent bond
Bond formed by the sharing of electrons between atoms
van der Waals forces
A slight attraction that develops between the oppositely charged regions of nearby molecules, (not as strong as ionic or covalent bonds), can hold molecules together (gecko on wall)
Cohesion
Attraction between molecules of the same substance, water's cohesion causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on a smooth surface, why some insects and spiders can walk on a pond's surface (strong attraction between water molecules produces "surface tension" that can support light objects)
Adhesion
Attraction between molecules of different substances, read the volume in a cylinder at eye level (the surface of the water in the graduated cylinder dips slightly in the center because the adhesion between the water molecules and glass molecules is stronger than the cohesion between water molecules)
Mixture
a material composed of two or more elements or compounds that are physically mixed together but not chemically combined
Solution
Mixture of two or more substances in which the molecules of the substances are evenly distributed
Solute
Substance that is dissolved in a solvent to make a solution
Solvent:
Substance in which a solute is dissolved to form a solution
pH scale
Measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14
Acid
Any compound that forms H+ ions in a solution, Acidic solutions contain higher concentrations of H+ ions than pure water and have pH values below 7 (stomach acid)
Base
ompound that produces hydroxide ions (OH-) in solution., Basic, or alkaline, solutions contain lower concentrations of H+ ions than pure water and have pH values above 7
Buffer
Weak acid or base that can react with strong acids or bases to help prevent sharp, sudden changes in pH, homeostasis (body must be kept at 6.5-7.5)
Monomer
Small unit that can join together with other small units to form polymers
Polymer
Large compound formed from combinations of many monomers
Dehydration
Two monomers are joined with the loss of a water molecule
Hydrolysis
Two monomers are split by the addition of water
Synthesis
The formation of compounds through one or more chemical reactions involving simpler substances
Monosaccharide
Single sugar molecule
Polysaccharide
Large macromolecule formed from monosaccharaides
Saturated
fatty acids contain the maximum possible number of hydrogen atoms, carbon-carbon single bonds
Unsaturated
if there is at least one carbon-carbon double bond
Triglyceride
Glycerol attached to three fatty acid molecules - store energy as fat
Phospholipid
Forms biological membranes, two fatty acid chain
Nucleotide
Monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base
Deoxyribonucleic acid (DNA):
Nucleic acid that contains the sugar deoxyribose
Ribonucleic acid (RNA)
Single-stranded nucleic acid that contains the sugar ribose
Amino acid:
Compound with an amino group (-NH2) on one end and a carboxyl group (-COOH) on the other end
Peptide bond
Bond between amino acids
Chemical reaction
process that changes, or transforms, one set of chemicals into another (mass and energy conserved), always involve changes in the chemical bonds that join atoms in compounds
Reactant
Element or compound that enters into a chemical reaction
Product
Element or compound produced by a chemical reaction
Activation energy
Energy needed to get a reaction started, a factor in whether the overall chemical reaction releases energy or absorbs energy
Catalyst
Substance that speeds up the rate of a chemical reaction, work by lowering a reaction's activation energy
Enzyme
Protein that acts as a biological catalyst, speed up chemical reactions that take place in cells, very specific (generally catalyzing only 1 chemical reaction), provide a site where rectants can be brought together to react, site reduces energy needed for reaction
Substrate
Reactant of an enzyme-catalyzed reaction
Competitive inhibitor
Binds active site
Non-competitive inhibitor
Binds somewhere else (not active site)
Coenzyme
Enzymes often need coenzymes to function properly. Coenzymes are usually vitamins