Glossary of Microbiology 240 - Chapter 2

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What is matter?
has mass and takes up space, is composed of one or more elements.
What is an element?
a substance that can't be decomposed into substances with different properties.
What is a molecule?
a combination of 2 or more atoms
What is a compound?
a combination of 2 or more elements
what is a mixture
2 or more elements (or compounds) mingling without any chemical bonding
what is an atom?
smallest unit of an element of matter that can enter into a chemical reaction
what is a proton?
a positively charged particle
what is a neutron?
an uncharged particle
what is an electron?
a negatively charged particle in motion around the nucleus of an atoms
what is an isotope?
form of a chemical element where the number of neutrons in the nucleus is different from the other forms of that element
what is an ion?
a negatively or positively charged atom or group of atoms
what is an ionic bond?
a bond formed when atoms gain or lose electrons in the outer energy levels.
what is a covalent bond?
a bond in which the electrons of one atoms are shared with another atom
what is a hydrogen bond?
bond between a hydrogen atom covalently bonded to oxygen or nitrogen and another covalently bonded oxygen or nitrogen atom
what is molecular weight?
the sum of the atomic weights of all atoms making up a molecule.
what is a mole?
an amount of a chemical equal to the atomic weights of all the atoms in a molecule of the chemical.
what is an endergonic reaction?
a chemical reaction that requires energy
what is an exergonic reaction?
a chemical reaction which releases energy
what is a synthesis reaction?
chemical reaction in which 2 or more atoms combine to form a new, larger molecule.
what is anabolism?
all synthesis reactions in a living organism; the building of complex organic molecules from simpler ones.
What is condensation (dehydration)?
Where an H+ molecule is removed from one molecule, OH- is removed from another and the 2 molecules join leaving H2O as a by product. (monomers to polymers)
What is a decomposition reaction?
Occur when a molecule is split into smaller molecules ions or atoms. AB --> A + B
What is catabolism?
all decomposition reactions in a living organism; the breakdown of complex organic compounds into simpler ones
what is a hydrolysis reaction?
a decomposition reaction in which chemicals react with the H+ and OH- of a water molecule.
what is ane exchange reaction?
a chemical reaction that has both synthesis and decomposition components
what is an organic compound?
a molecule that contains carbon and hydrogen
what is an inorganic compound?
a small molecule that does not contain carbon and hydrogen
what is a polar molecule?
a molecule with unequal distribution of charges
what is a solvent?
a dissolving medium
what is a solute?
a substance dissolved in another substance.
what is dissociation?
the separation of a compound into positive and negative ions in solution
what is an acid?
a substance that dissociates into one or more hydrogen ions (H+) and one or more negative ions.
what is a base?
a substance that dissociates into one or more hydroxide ions (OH-) and one or more positive ions.
what is a salt?
a substance that dissolves in water to cations and anions, neither of which is H+ or OH-
what is pH?
the symbol for hydrogen ion concentration; a measure of the relative acidity or alkalinity of a solution
what is a functional group?
an arrangement of atoms in an organic molecule that is responsible for most of the chemical properties of that molecule.
what is a monomer?
a small molecule that collectively combines to form polymers
what is a polymer?
a molecule consisting of a sequence of similar molecules, or monomers.
what is a macromolecule?
a large organic molecule
what is a carbohydrate?
an organic compound composed of carbon, nydrogen and oxygen, with the hydrogen and oxygen present in a 2:1 ratio; barbohydrates include starches, sugars and cellulose.
what is a monosaccharide?
a simple sugar consisting of 3-7 carbon atoms
what is a disaccharide?
a sugar consisting of two simple sugars or monosaccharides.
what is a polysaccharide?
a carbohydrate consisting of 8 or more monosaccharides joined through dehydration synthesis
what is a lipid?
a non-water soluble organic molecule, including triglycerides, phospholipids and sterols
what is a tryglyceride?
a simple lipid consisting of glycerol and 3 fatty acids.
what is a fatty acid?
they have backbones of up to 36 carbons, a carboxyl group (COOH) at one end and hydrogen atoms at nearly all other locations
what is a phospholipid?
made of 2 fatty acids attached to a glycerol molecule, which is also attached to a phosphate group and another polar group. This is the primary component of cell membranes.
what is sterol?
all have rigid four-ring backbone, but lack fatty acid tails. Includes cholesterol and are components of Vitamin D, bile salts, cell membranes and steroid hormones
what is a steroid?
a specific group of lipids, including cholesterol and hormones.
what is a protein?
a large molecule containing carbon, hydrogen, oxygen and nitrogen (and sulfure); some proteins have a helical structure and others are pleated sheets.
what is an amino acid?
organic compound made up of an amino group, a carboxyl group, a hydrogen atom and an "r" group, all attached to a central carbon atom. Many amino acids linked together form proteins. (20 different types of amino acids)
what is a peptide bond?
a bond joining the amino acid group of one amino acid to the carboxyl group of a second amino acid with the loss of a water molecule (dehydration synthesis).
what is primary structure?
a specific protein will have a specific sequence of amino acids in a specific order.
what is secondary structure?
the coils, loops, bends, etc. of a polypeptide chain as it interacts with other portions of itself or other chains nearby
what is tertiary structure?
overall structural arrangement of the entire protein. Occurs when teh helix folds irregularly, forming disulfide bonds, hydrogen bonds and ionic bonds between amino acids in the chain.
what is Quarternary structure?
arises when proteins made up of multiple polypeptide chains are held together by hydrogen bonds and other weark forces. (Hemoglobin, insulin, keratin, collagen, etc.)
what does denature mean?
a change in the molecular structure of a protein, usually making it nonfunctional.
what is a nucleic acid?
a macromolecule consisting of nucleotides; DNA and RNA are nucleic acids
what is DNA?
Deoxyribonucleic acid; a double strand nucleic acid. double helix. contains the nucleotides thymine, adenine, cytosine and guanine.
what is ATP?
Adenosine triphosphate. a nucleotide with 3 phosphate groups attached to it. Primary source of energy for cellular activities. has ribonse, adenine and 3 phosphate groups. Made by dehydration synthesis. broken by hydrolysis for use of energy.
What is ADP?
adenosine diphosphate; the substance formed when ATP is hydrolyzed and energy is released.
What is the first property of water that is important to life? and why is it important?
capable of forming four hydrogen bonds with nearby water molecules. This attraction gives water a high boiling point (100C) which means it exists as mostly liquid ont he Earth's surface. Water becomes more dense in its crystalline structure (ice) which means it acts as an insulator on the surfaces of lakes and streams.
what is the second property of water that is important to life? and why is it important?
the polarity of water makes it an excellent dissolving medium. Allowing molecules to dissociate easily.
What is the third property of water that is important to life? and why is it important?
polarity accounts for water's characterisitic role as a reactant or product in many chemical reactions. a key reactanct in the digestive processes of organisms.
what is the fourth property of water that is important to life? and why is it importatn?
the hydrogen bonds make water a great temperature bugger. maintains a more constant temperature protecting the cell.

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