This site is 100% ad supported. Please add an exception to adblock for this site.

General Chemistry

Terms

undefined, object
copy deck
Ribosomal RNA (rRNA)
an important part of the ribosome where the proteins are made
light reaction (photolysis)
a first step in photosynthesis is the decomposition of water molecules to separate hydrogen and oxygen components. this decomposition is associated with processes involving chlorophyll and light and is thus known as this
quaternary structure
manner in which two or more independently folded subunits fit together
coenzymes
these are metal ions or non-proteinaceous organic molecules that bind briefly and loosely to some enzymes. its necessary for the catalytic reaction of such enzymes
non-polar covalent bond
a bond where the electrons are pulled exactly equally by two atoms
Compound
a combination of elements present in definite proportions by weight. These are substances which can be decomposed by chemical means
endergonic reaction
require the addition of free energy from an external source
polysaccharide
a complex compound composed of a large number of glucose units. examples are starch, cellulose, and glycogen
hydrocarbons
the simplest organic molecules are this. these compounds are composed solely of carbon and hydrogen. they can exist as chains (e.g., butane) or rings (e.g., benzene)
entropy
energy distribution
lipids
organic compounds that dissolve poorly, if at all, in water. all are composed of carbon, hydrogen, and oxygen where the ratio of hydrogen atoms to oxygen atoms is greater than 2:1. a molecule of this is composed of 1 glycerol and 2 fatty acids
Carbohydrates
compounds composed of carbon, hydrogen, and oxygen, with the general molecular formule CH2O.
ionic bond
the complete transfer of an electron from one atom to another. they form between strong electron donors and strong electron acceptors
pH
the degree of acidity or alkalinity is measured by this
Hydrogen bond
formed when a single hydrogen atom is shared between two electronegative atoms, usually nitrogen or oxygen
nucleic acids
long polymers invovled in heredity and in the manufacture of different kinds of proteins. the two most important are DNA and RNA
ions
atoms or groups of atoms which have lost or gained electrons. one is always electropositive and the other electronegative
tertiary stucture
the three-dimensional folding pattern, which is super-imposed on the secondary structure
enzyme
protein catalysts that lower the amount of activation energy needed for a reaction, allowing it to occur more rapidly
pH<7
acidic
dark reaction (CO2 Fixation)
in this second phase, the hydrogen that results from photolysis reacts with CO2 and carbohydrate forms. does not require light
proteins
composed of carbon, hydrogen, oxygen, nitrogen, and sometimes phosphorus and sulfur. it is approximately 50% of the dry weight of living matter
covalent bond
the sharing of pairs of electrons between atoms. may be single, double, or triple
neutron
electrically neutral particle of the nucleus
Ribonucleic Acid
involved in protein synthesis. it is composed of the sugar ribose and nitrogenous base uracil instead of thymine
amino acids
they are the building blocks of protein (20 of them)
mixtures
contain two or more substances, each of which retains its original properties and can be separated from the others by relatively simple means. they do not have a definite composition
Transfer RNA (tRNA)
moves amino acids into the proper positions that the mRNA calls for
allosteric inhibition
during this process, an inhibitory molecule called a negative modulator binds to the enzyme and stabilizes it in its inactive conformation
proton
positively charged particle of the nucleus
chemical reaction
any process in which at least one bond is either broken or formed. the outcome is a rearrangement of atoms and bonding patterns
electon
negatively charged particle which orbits the nucleus
Element
a substance which cannot be decomposed into simpler or less complex substances by ordinary chemical means
third law of thermodynamics
a perfect crystal which is a completely ordered system, at absolute zero (0 degrees Kelvin) would have perfect order, and therefore its entropy would be zero
Krebs Cycle (Citric Acid Cycle)
the final common pathway by which the carbon chains of amino acids, fatty acids, and carbs are metabolized to yield CO2. Pyruvic acid is converted to acetyl coenzyme A and through a series of reactions, citric acid is formed
atoms
each element is made up of one type of this. the smallest part of an element which can combine with other elements
disaccharide
a double sugar or a combination of two simple sugar molecules. sucrose is a familiar disaccharid as are maltose and lactose
base
a compound which dissociates in water and yields hydroxyl ions [OH-]. they are proton acceptors
acid
a compound which dissociates in water and yields hydrogen ions [H+]. it is referred to as a proton donor
nucleotides
these are the building blocks of nucleic acids. complex molecules composed of a nitrogenous base, a 5-carbon sugar, and a phosphate group
first law of thermodynamics
in any process, the sum of all energy changes must be zero
ATP
Adenosine triphosphate and is a coenzyme essential for the breakdown of glucose. when the bonds in this are hydrolyzed, a large amount of energy is released
polypeptides
amino acids are assembled into these by means of peptide bonds. this is formed by a condensation reaction between the COOH groups and the NH2 groups
Van der Waals Forces
weak linkages which occur between electrically neutral molecules or parts of molecules which are very close to each other
polar covalent bond
a bond in which the charged is distributed asymmetrically within the bond
pH>7
basic
phospholipid
a variety of a substituted lipid which contains a phosphate group
Deoxyribonucleic acid
chromosomes and genes are composed mainly of this. it is composed of deoxyribose, nitrogenous bases, and phosphate groups
NAD
Nicotinamide Adenine Dinucleotide. it is a coenzyme. participates in a large number of oxidation-reduction reactions in cells, including those in cellular respiration
glycolysis
refers to the breakdown of glucose which marks the start of the anaerobic reactions of cellular respiration. ATP is the energy source which activates glucose and initiates the process of glycolysis
atomic nucleus
small, dense center of an atom
Messenger RNA (mRNA)
carries the genetic information coded for in the DNA to the ribosomes, and is responsible for the translation of that information into a polypeptide chain
primary structure
number of polypeptide chains and the number, type, and sequence of amino acids in each protein molecule
Allosteric enzyme
one that can exist in two distinct conformations. usually it is active in one conformation and inactive in the other
steroids
complex molecules which contain carbon atoms arranged in four interlocking rings. some of these are of biological importance like vitamin D, bile salts, and cholesterol
enthalpy
total energy content of a system
substrate
the molecule upon which an enzyme acts. the atoms of this are arranged so as to fit into the active site of the enzyme that acts upon it. an enzyme usually affects only one of this
second law of thermodynamics
any system tends toward a state of greater stability- stability meaning randomness, disorder, and probability
monosaccharides
a simple sugar or a carbohydrate which cannot be broken down into a simpler sugar. its molecular formula is C6H12O6, and the most common is glucose
exergonic reaction
release free energy; all spontaneous reactions are this
Hydrophobic interactions
occur between groups that are insoluble in water. these groups, which are non-polar, tend to clump together in the presence of water
pH=7
neutral
secondary structure
characterized by the same bond angles repeated in successive amino acids which gives the linear molecule a recurrent structural pattern

Deck Info

63

permalink