Biochemistry
The study of the molecules and chemical reactions that occur in living cells
Neutron
An uncharged particle found in the nucleus of the atom
Proton
An positively charged particle found in the nucleus of the atom
Electron
An negatively charged particle found outside the nucleus of the atom
Iso
Same
Isotope
Two or more of the same elements having equal amount of protons but different amount of neutrons in their nucleus
Ion
Any atom or molecule with a charge, due to the loss or gain of electron
Cation
A positively charged ion because it has lost an electron
Anion
A negatively charged ion because it has gained an electron
Molecule
Composed of one or more than one element
Compound
A molecule composed of two or more different elements
Isomer
A molecule with the same molecular formula as another molecule, but with a different chemical structure
Molecular Weight
Equal to the sum of the atomic weights, measured in atomic mass units (AMU), and is useful for calculating concentrations
Element
The simplest form of matter to have unique chemical properties
Mineral
inorganic element extracted from the soil by plants and passed up the food chain to humans and other organisms
Biological Half-life
The time required for half of it to disappear from the body
Electrolyte
Substances that ionize in water (acids, bases, or salts) and form solutions capable of conducting electricity
Free Radical
Chemical particles with an odd number of electrons
Antioxidant
A chemical that neutralizes free radicals
Chemical Bond
Forces by which a molecule is held together, and molecules are attracted to one another
Ionic Bond
A strong attraction between a cation and an anion
Covalent Bond
Formed by the sharing of electrons between two atoms
Hydrogen Bond
A weak attraction between a slightly positive region in one molecule and a slightly negative region in a different molecule
Basic Structure of an Amino Acid
A central carbon atom (Radical) with an amino (-NH2) and a carboxyl (-COOH) group
Chemical Reaction
A process that involves the formation or breakdown of molecules
Decomposition Reaction
A larger molecule is broken down into smaller parts
Synthesis Reaction
Two or more smaller molecules combine into a larger one
Exchange Reaction
Atoms are traded between molecules
Dehydration Synthesis
Two or more smaller molecules combine into a larger one
Catabolism
Consists of energy-releasing (exergonic) decomposition reactions
Anabolism
Consists of energy-storing (endergonic) synthesis reactions
Carbon
The foundation of biological molecules
Macromolecule
Any molecule of large size and high molecular weight, such as a protein or starch
Monomer
The identical or similar subunits of a larger molecule
Examples of a Carbohydrate
Monosaccharide, Disaccharide, Polysaccharide
Glucose
Known as blood sugar, C6H12O6
Glycogen
The polysaccharide used for energy storage in animals
Starch
The only plant polysaccharide that humans can digest
Glycolipid
A phospholipid molecule covalently bonded to a carbohydrate
Fatty Acid
Contain both a carboxyl group and a methyl group
Triglyceride
A lipid composed of three fatty acids joined to a glycerol
Phospholipid
A lipid that consists of two hydrophobic fatty acids and a hydrophilic phosphate head
Amino Acid
The monomeric subunits that make up a protein
Peptide Bond
The type of bond that holds amino acids together in a protein molecule
Primary Structure
The protein’s sequence of amino acids joined by peptide bonds
Secondary Structure
Alpha helix or beta sheet formed by hydrogen bonding
Tertiary Structure
Folding and coiling due to inactions among R groups and between R groups and surrounding water
Quaternary Structure
Association of two or more polypeptide chains with each other
Adenosine Triphosphate (ATP)
The energy molecule that is produced by cellular respiration and used in metabolic reactions
Law of Mass Action
States that reactions proceed from the side of the reaction with the greater quantity to the side with the lesser quantity
Oxidation-reduction Reaction
A chemical reaction in which electrons are transferred between molecules
Chemical Energy
Potential energy stored in the bonds of molecules
Adenosine Triphosphate (ATP)
The energy molecule that is produced by cellular respiration and used in metabolic reactions
Lipid
Hydrophobic organic molecules, such as fatty acids, fats, steroids, and prostaglandins
Steroid
The general term for a lipid molecule that consists of four interconnected carbon rings, examples are cholesterol, testosterone, or estrogen
Enzyme
A protein that functions as a biological catalyst, speed up reaction rates by lowering the activation energy of a specific reaction, are not consumed in the reactions they catalyze, show enzyme-substrate specificity
Nucleotides
Composed of a nitrogenous base, a monosaccharide, and a phosphate group
Nucleic Acid
An acidic polymer of nucleotides, found or produced in the nucleus, that functions in heredity and protein synthesis
Deoxyribonucleic Acid (DNA)
The largest of polymers of nucleotides
Monosaccharide
Referred as a simple sugar, or sugar monomer
Saturated Fatty Acid
A fatty acid containing as many hydrogen as possible and in which the carbon bonds are all single bonds
Adipose Tissue
A type of connective tissue that provides energy storage, thermal insulation, and protective cushioning
Denaturation
A change in three-dimensional conformation of a protein that destroys its functional properties
Phosphorylation
The addition of an inorganic phosphate to an organic molecule
Polyunsaturated Fatty Acid
A fatty acid that has two or more double bonds within its carbon chain
Glycoprotein
A protein molecule with a smaller carbohydrate covalently bonded to it
Essential Fatty Acid
A fatty acid that must be obtained from the diet because the body cannot synthesize them
Substrate
The substance upon which an enzyme acts
Condensation Reaction
A water molecule is removed from a molecule when it creates a covalent bond
Cyclic Adenosine Monophosphate (cAMP)
A molecule that is produced from ATP and which often serves as a second messenger
Alpha Helix
A secondary structure of protein that has a spiral shape
Beta Sheet
A secondary structure of protein that is a ribbon-like shape
Glycoprotein
A protein molecule bonded to a smaller carbohydrate molecule
Cholesterol
A steroid that is a precursor for all other steroids in the body
Activation Energy
The energy required to initiate or begin a chemical reaction
Factors that Affect Enzyme Conformation
pH and Temperature
Kinase
Any enzyme that adds an inorganic phosphate (PI) group to another organic molecule
Proteins
Act as receptors on cells’ surfaces, catalyze chemical reactions, make up molecules that can transport oxygen
Active Site
The substrate-binding site of an enzyme
Energy
The capacity to do work
Potential Energy
Energy contained in an object because of its position or internal state
Kinetic Energy
Energy that is doing work
Free Energy
All potential energy available in a system
Functional Group
Groups of atoms that are added to carbon backbones and that give organic molecules a variety of unique properties
Metabolic Pathway
A series of reactions, where each step is catalyzed by a specific enzyme
Polysaccharide
A complex carbohydrate as it is a polymer of simple sugars, examples are glycogen, starch, and cellulose
Catalyst
Substance that lowers the activation energy of the reaction and speed up the rate of reaction, may bind to reactants and bring them into proximity, may position reactants in such as a way as to favor their reaction, they are not consumed by the reaction
Enzyme-substrate Complex
The structure formed by the combining of the enzyme and its specific substrate
Hydrolysis
The chemical reaction that breaks a covalent bond in a. molecule by adding an OH group to one side of the bond and H to the other side, thus consuming a water molecule
Ligand
A chemical that binds reversibly to a receptor site on a protein, such as a neurotransmitter that binds a membrane receptor, or a substrate that binds to an enzyme
Radioactivity
When an unstable atomic nuclei breaks down, releasing particles and energy
Guanosine Triphosphate (GTP)
A nucleotide involved in energy transfers, which may donate a phosphate to help regenerate ATP
Prostaglandin
An eicosanoid that is a modified fatty acid with a single five-carbon ring
Trace Element
An element that plays a physiological role in the body, but which accounts for less than 0.02% of the body weight
Valence Electron
Determine the reactive properties of an atom
Substrate
An organic cofactor that is required for an enzyme to function
Ionizing Radiation
A general term for radiation capable of converting atoms to ions or free radicals
Radioactivity
The process of energy being released from the decay of unstable radioisotopes
Cellulose
The structural polysaccharide found in plant cells
Physical Half-life
The time required for one-half of a quantity of a radioactive element to decay to a stable isotope
Amphipathic
Contains a hydrophobic and a hydrophilic region
Reducing Agent
A molecule that is oxidized in an oxidation-reduction reaction
Proteoglycan
A molecule composed predominantly of a carbohydrate covalently bonded to a smaller protein component
Oxidizing Agent
A molecule that is reduced in an oxidation-reduction reaction
Conformation
The overall three-dimensional shape of a protein