85 terms

Biology Unit 2: Vocabulary


Terms in this set (...)

The basic unit of matter.
A pure substance made of only one type of atom.
A substance formed by the chemical combination of two or more elements in definite proportions.
Atomic Number
The number of protons in the atom.
Ionic Bond
Chemical bond formed when one or more electrons are transferred from one atom to another.
Covalent Bond
Chemical bond formed when the electrons are shared between atoms.
The small units.
The large units.
Atoms of the same element that differ in the number of neutrons they contain.
An element that exists in two or more forms.
Dehydration Synthesis
A chemical reaction that builds up molecules by losing water molecules.
The process of splitting a compound into fragments with the addition of water. (Breaks down water.)
The process of creating large molecules from smaller molecules, utilizing energy.
The process of breaking large molecules down into smaller molecules, releasing energy.
Primarily composed of: Carbon, Hydrogen, Oxygen. [CH2O]n format.
Known for energy storage.
Monomer carbohydrate. (One unit)
Polymer carbohydrate. (Multiple units.)
(Note: Disaccharide has 2 units.)
Fats. Composed of carbon and hydrogen (often in chains); not soluble in water.
(Store energy, used as phospholipids in membranes.)
Macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen.
Do the work in the cell.
Amino Acid
Organic compounds with an amino group (-NH2) on one end and a carboxyl group (-COOH) on the other end.
Primary Structure
The sequence of amino acids.
Secondary Structure
Coils and folding of the amino acid chain.
Tertiary Structure
The three-dimensional shape of the protein is stabilized by interactions between R-groups (side chains).
Quaternary Structure
Association between two or more different polypeptide chains (protein subunits) found in only some proteins.
Endothermic Reaction
Chemical reactions that absorb energy.
Exothermic Reaction
Chemical reactions that release energy.
Activation Energy
The energy needed to get a reaction started.
A substance that speeds up the rate of the reaction by lowering the activation energy.
Proteins that act as biological catalysts.
All of the chemical reactions that occur within an organism.
A compound that forms H+ ions in solution.
A compound that forms OH- ions in solution.
A weak acid or base that can react with strong acids or bases.
Prevents sharp, sudden changes in pH.
A substance on which an enzyme acts during a chemical reaction.
Active Site
Pockets in the folds on enzyme surfaces.
Competitive Inhibition
Molecules sit in the active site of the enzyme and prevent the entry of the substrate.
Uncompetitive Inhibition
Molecules attach to an allosteric site and change the shape of the enzyme and thus the shape of the active site.
Enzyme is now less compatible with its substrate.
Allosteric Site
Site on the enzyme used for uncompetitive inhibition.
Nucleic Acid
Made up of nucleotides joined into a chain by covalent bonds. (Polymer of nucleotides.)
One part of a nucleic acid.
(Five-carbon sugar attached to a phosphorous and a nitrogenous base.)
Give the acronym for the list of the most common elements found in the human body.
Positively charged subatomic particle.
Neutrally charged subatomic particle.
Negatively charged subatomic particle.
Mass Number
Total number of protons and neutrons.
Atomic Weight
Weighted average of the masses of an element's isotopes
Valence Shell
Most outer shell of electrons.
The smallest unit of most compounds.
Functional group: COOH.
Functional group: PO4.
Functional group: HO.
Functional Group: NH2
Carbohydrate with exactly 2 units.
Saturated Fats
Lipids with no C=C bonds.
Unsaturated Fats
Lipids with C=C bonds.
Polyunsaturated Fats
Lipids with more than 1 C=C bond.
The name for the polymer of amino acids.
Peptide bond
Bond between 2 amino acids.
The sidechain that makes each amino acid different.
Hydrogen Bonds
Secondary protein structure is held together with ___.
Adenine, Thymine, Cytosine, Guanine, Uracil
Name of the nucleotides.
Name of the 5-carbon sugar in DNA.
Law of Conservation of Energy; First Law of Thermodynamics
Energy can neither be created nor destroyed.
Second Law of Thermodynamics
In a closed, isolated, system entropy is strictly increasing.
The ability/capacity to cause a change.
Chemical Reaction
Process that changes or transforms one set of chemicals into another.
2H2O2 -> 2H2O + O2
Equation of the reaction catalase catalyzes.
Temperature, pH, concentration
Examples of things that affect enzyme performance.
Neutral pH
Higher pH (7-14) indicates the substance is a(n) ___.
Lower pH (1-7) indicates the substance is a(n) ___.
Suffix to indicate enzymes.
Induced Fit Model
A model for enzyme-substrate interaction.
The proper substrate induces the proper alignment of the active site that enables the enzyme to perform its catalytic function.
Lock-and-Key Model
A model for enzyme-substrate interaction. (Obsolete)
Enzymes and substrates have corresponding shapes like a lock and key.
Process in which one strain of bacteria changes due to information from another strain of bacteria.
5'; 3'
The ___ carbon bonds from the first nucleotide to the ___ carbon from another nucleotide.
Sugar-phosphate backbone
The bonds between the phosphate groups and the sugars makes the ___ in nucleic acids.
The two strands of DNA run in opposite directions. The nitrogenous bases contact in the middle.
Examples of nucleic acids.
Chargaff's Rule, 1949
The observation that the number of adenine and thymine are roughly the same.
(Similarly, guanine and cytosine.)
Rosalind Franklin, 1950s
The scientist who used X-Ray diffraction and found an X-shape, indicating 2 twisted strands.
Watson and Crick, 1953
Built a model of DNA using Franklin's research.
Griffith, 1928
Discovered transformation by observing harmless R stains turn into S strains ones and give a mouse pneumonia.
Avery, 1944
Discovered that DNA caused transformation by trial-and-error destroying things until it stopped happening.
Hershey & Chase, 1952
Discovered that bacteriophages inject their genetic information into bacteria by marking the information with radioactive isotopes.