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440 Cards in this Set
- Front
- Back
Matter
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Anything that has mass or takes up space
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atomic weight
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the weight of the protons plus the neutrons
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polar covalent bond
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a bond where one atom is bonded to a more electronegative atom , meaning the electrons are not shared equally between atoms
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isotope
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an atom that has a differing number of neutrons with the same number of protons as the original element
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ion
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a atom with a non 0 charge
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radioactive isotope
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an isotope that emits radiation
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chemical bond
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two atoms that are bonded together because they either share electrons or one takes them from the other
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cation
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positively charged ion
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atom
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smallest unit of matter that retains the properties of an element
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neutron
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An electrically neutral particle (a particle having no electrical charge), found in the nucleus of an atom.
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potential energy
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energy from chemical bonds or position
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molecule
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structure formed from two or more atoms combining in bonds
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ionic bond
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bond in which one atom takes electrons from another , bonding the two together
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proton
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the positive charge in the nucleus
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energy level
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Any of several different states of potential energy for electrons in an atom
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structural formula
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the notation in which a bond is signified by a dash, example: H-H
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hydrogen bond
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the bond formed when a hydrogen atom covalently bonds with one electronegative atom, and then these two atoms are covalently bonded to yet another electronegative atom… water.
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electron
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A subatomic particle with a single negative charge. One or more electrons move around the nucleus of an atom
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molecular formula
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A type of molecular notation indicating only the quantity of the constituent atoms; ex: 2H
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chemical reactions
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happens between two particles that are attracted or repelled from each other
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double covalent bond
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a bond where an atom shares two pairs of elections with another atom
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reactants
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substances that are in place before the reaction takes place
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dalton
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A measure of mass for atoms and subatomic particles
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electron shell
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the general location around the atom that the electrons can be found in varying on their energy
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electronegativity
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the attraction of a particular kind of atom for the electrons of a covalent bond
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chemical equilibrium
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state where the reactants are equal to the products
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orbital
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notated as s p or d, the orbital's describe how many atoms are in the valence shell of the atom
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polar molecule
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a molecule (such as water) with opposite charges on opposite sides
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celsius scale
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A temperature scale (°C) equal to 5/9 (°F - 32) that measures the freezing point of water at 0°C and the boiling point of water at 100°C
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solute
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a substance that is dissolved in a solution (sugar would be the solute in a solution of sugar and water).
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hydrogen ion
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A single proton with a charge of +1
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cohesion
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The binding together of like molecules, often by hydrogen bonds
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calorie
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The amount of heat energy required to raise the temperature of 1 gram of water by 1 degree Celsius; also the amount of heat energy that 1 gram of water releases when it cools by 1 degree Celsius
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solvent
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dissolving agent of a solution
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molarity
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A common measure of solute concentration, referring to the number of moles of solute per liter of solution
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adhesion
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the attraction between different kinds of molecules
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kilocalorie
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A thousand calories; the amount of heat energy required to raise the temperature of 1 kg of water by 1 degree Celsius
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aqueous solution
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A solution in which the solvent is water
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hydroxide ion
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A water molecule that has lost a proton; OH-
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surface tension
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A measure of how difficult it is to stretch or break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules
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hydrophilic
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having an affinity for water
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acid
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A substance that increases the hydrogen ion concentration of a solution; 0-7 on a pH scale
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kinetic energy
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The energy of motion, which is directly related to the speed of that motion. Moving matter does work by imparting motion to other matter
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specific heat
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The amount of heat that must be absorbed or lost for 1 gram of a substance to change its temperature by 1 degree Celsius
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hydrophobic
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having an aversion (disliking) to water; tending to coalesce and form droplets in water
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base
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a substance that reduces the hydrogen ion concentration of a solution; 7-14 on a pH scale
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heat
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the a. The total amount of kinetic energy due to molecular motion in a body of matter. Heat is energy in its most random form.
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evaporative cooling
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the property of a liquid whereby the surface becomes cooler during evaporation, owing to a loss of highly kinetic molecules to the gaseous state
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mole
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number of grams of a substance that equals its molecular weight ub Daltons and contains Avogadro’s number of molecules
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pH Scale
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measure of hydrogen ion concentration equal to –log [H+] and ranging in value from 0-14
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temperature
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measure of the intensity of heat in degrees, reflecting the average kinetic energy of the molecules
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solution
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liquid that is a homogenous mixture of two or more substances
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molecular weight/mass
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sum of the masses of all the atoms in a molecule
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buffer
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substance that consists of acid and base forms in a solution and that minimizes changes in the pH when extraneous acids or bases are added to the solution
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precipitation
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product of the condensation of atmospheric water vapor
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organic chemistry
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study of carbon compounds
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enantiomer
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molecules that are mirror images of each other
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hydrocarbon
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organic molecules consisting only of carbon and hydrogen
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functional group
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the components of organic molecules that are most commonly involved in chemical reactions
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isomer
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compounds that have the same number of atoms of the same elements but different structures and hence different properties
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structural isomer
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differ in the covalent arrangements of their atoms
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geometric isomer
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have the same covalent partnerships, but they differ in their spatial arrangements
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hydroxl group
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(Structure) consists of a hydrogen atom joined to an oxygen atom by a polar covalent bond/ (Compounds) alcohol/ (properties) polar as a result of the electronegative oxygen atom drawing electrons toward itself
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carbonyl group
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(Structure) consists of carbon atom joined to an oxygen atom by a double bond/ (Compounds) aldehydes & ketones
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aldehyde
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carbonyl group; when the carbonyl group is at the end of the carbon skeleton
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ketone
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carbonyl group; if the carbonyl group is within a carbon skeleton – name of a compound of a carbonyl group
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carboxyl group
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Structure) when an oxygen atom is double-bonded to a carbon atom that is also bonded to a hydroxyl group; (compounds) Carboxylic acids or organic acids; (properties) has acidic properties because it is a source of hydrogen ions
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amino group
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Structure) consists of a nitrogen atom bonded to two hydrogen atoms and to the carbon skeleton; (compound) amine; (properties) acts as a base
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sulfhydrl group
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Structure) consists of a sulfur atom bonded to an atom of hydrogen; resembles a hydroxyl group in shape; (Compound) thiols; (Properties) two sulfhydryl groups can interact to help stabilize protein structure
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phosphate group
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(Structure) a phosphorus atom is bonded to four oxygen atoms: one oxygen is w/ double bond, one oxygen is bonded to the carbon Skelton; two oxygens carry negative charges. The phosphate group is an ionized form of a phosphoric acid group; (Compound) organic phosphates; (Properties) can transfer energy between organic molecules
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polymer
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A long molecule consisting of many similar or identical monomers linked together
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cellulose
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A structural polysaccharide of cell walls, consisting of glucose monomers joined by β–1,4–glycosidic linkages
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polypepetide
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a polymer of amino acids linked by peptide bonds (PROTEIN)
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quaternary structure
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when a protein consists of two or more polypeptide chains
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monomer
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The subunit that serves as the building block of a polymer
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chitin
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A structural polysaccharide of an amino sugar found in many fungi and in the exoskeletons of all arthropods
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amino acid
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An organic molecule possessing both carboxyl and amino groups. Amino acids serve as the monomers of proteins
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denaturation
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In proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive. Denaturation occurs under extreme conditions of pH, salt concentration, and temperature
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condensation reaction
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A reaction in which two molecules become covalently bonded to each other through the loss of a water molecule
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dehydration reaction
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A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule
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lipid
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one of a family of compounds, including fats, phospholipids, and steroids, that are insoluble in water
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protein
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A three–dimensional biological polymer constructed from a set of 20 different monomers called amino acids
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fat
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A biological compound consisting of three fatty acids linked to one glycerol molecule
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conformation
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A protein’s conformation determines how it works
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hydrolysis
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A chemical process that lyses, or splits, molecules by the addition of water.
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fatty acid
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A long carbon chain carboxylic acid. Fatty acids vary in length and in the number and location of double bonds; three fatty acids linked to a glycerol molecule form fat
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peptide bond
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The covalent bond between two amino acid units, formed by a dehydration reaction-PROTEIN
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nucleic acid
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A polymer (polynucleotide) consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities. The two types are DNA and RNA
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carbohydrate
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A sugar (monosaccharide) or one of its dimers (disaccha–rides) or polymers (polysaccharides)
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primary structure
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the level of protein structure referring to the specific sequence of amino acids
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deoxyribonucleic acid (DNA)
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a double-stranded, helical nuclei acid molecule capable of replicating and determining the inherited structure of a cell’s proteins
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monosaccharide
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the simplest carbohydrate, active alone or serving as a monomer of disaccharides and polysaccharides. Also known as simple sugars
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saturated fatty acid
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a fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms that can attach to the carbon skeleton
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secondary structure
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the localized, repetitive coiling or folding of the polypeptide backbone of a protein due to hydrogen bond formation between peptide linkages
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ribonucleic acid (RNA)
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a type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases, usually single-stranded, functions in protein synthesis and as the genome of some viruses
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disaccharide
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a double sugar, consisting of two monosaccharides joined by dehydration synthesis
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unsaturated fatty acid
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a fatty acid possessing one of more double bonds between the carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton
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alpha helix
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a spiral shape constituting one form of the secondary structure of proteins, arising from a specific hydrogen-bonding structure
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nucleotide
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the building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group
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glycosidic linkages
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a covalent bond formed between two monosaccharides by a dehydration reaction
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steroid
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a type of lipid characterized by a carbon skeleton consisting of four rings with various functional groups attached
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beta pleated sheet
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beta pleated sheets are the second form of regular secondary structures in proteins
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pyrimidine
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one of two types of nitrogenous bases found in nucleotides; C, T, U
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polysaccharide
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a polymer of up to over a thousand monosaccharides, formed by dehydration reactions
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cholesterol
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a steroid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids
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tertiary structure
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irregular contortions of a protein molecule due to interactions of side chains involved in hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bridges
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purine
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One of two types of nitrogenous bonds found in nucleotides; have two organic rings; Adenine and guanine are purines
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starch
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a storage polysaccharide in plants consisting entirely of glucose
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ribose
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the sugar component of RNA
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glycogen
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an extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch
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disulfide bridges
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a strong covalent bond formed when the sulfur of one cysteine monomer bonds to the sulfur of another cysteine monomer in proteins
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polynucleotide
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a polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities
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double helix
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the form of native DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape
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metabolism
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the totality of an organism's chemical reactions, consisting of catabolic and anabolic pathways
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first law of thermodynamics
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principle of conservation of energy. Energy can be transferred and transformed, but it cannot be created or destroyed
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catalyst
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chemical agent that changes the rate of a reaction without being consumed by the reaction
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noncompetitive inhibitors
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A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing its conformation so that it no longer binds to the substrate.
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catabolic pathways
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A metabolic pathway that releases energy by breaking down complex molecules to simpler compounds
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second law of thermodynamics
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The principle whereby every energy transfer or transformation increases the entropy of the universe. Ordered forms of energy are at least partly converted to heat, and in spontaneous reactions, the free energy of the system also decreases
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activation energy
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The amount of energy that reactants must absorb before a chemical reaction will start; also called activation energy
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allosteric site
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site on enzyme other than active site where inhibitory molecules may bind to an enzyme
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anabolic pathway
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A metabolic pathway that synthesizes a complex molecule from simpler compounds.
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free energy
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The portion of a system’s energy that can perform work when temperature and pressure are uniform throughout the system. The change in free energy of a system is calculated by the equation ΔG = ΔH - T Δs, where T is absolute temperature
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substrate
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The reactant on which an enzyme works
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feedback inhibition
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A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway
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exergonic reaction
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A spontaneous chemical reaction, in which there is a net release of free energy
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active site
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The specific portion of an enzyme that attaches to the substrate by means of weak chemical bonds
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endergonic reaction
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A non-spontaneous chemical reaction, in which free energy is absorbed from the surroundings
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induced fit
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The change in shape of the active site of an enzyme so that it binds more snugly to the substrate, induced by entry of the substrate
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entropy
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A quantitative measure of disorder or randomness, symbolized by S
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kinetic energy
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The energy of motion, which is directly related to the speed of that motion. Moving matter does work by imparting motion to other matter
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cofactors
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Any inorganic non-protein molecule or ion that is required for the proper functioning of an enzyme. Cofactors can be permanently bound to the active site or may bind loosely with the substrate during catalysis; ex: minerals
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ATP
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An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells
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coenzyme
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An organic molecule serving as a cofactor. Most vitamins function as coenzymes in important metabolic reactions
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phosphorylated
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Referring to a molecule that has been the recipient of a phosphate group
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competitive inhibitors
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A substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics
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endomembrane system
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Synthesis of proteins, transport, metabolism, movement of lipids, and detoxification of poisons (Nuclear Envelope, Endoplasmic Reticulum, Golgi Apparatus, Lysosomes, Vacuoles, Plasma Membrane)
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nuclear envelope
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a double membrane that encloses the nucleus
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endoplasmic reticulum
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An extensive membranous network in eukaryotic cells, continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosome-free (smooth) regions
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lysosomes
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A membrane-enclosed sac of hydrolytic enzymes found in the cytoplasm of eukaryotic cells.
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Golgi Apparatus
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An organelle in eukaryotic cells consisting of stacks of flat membranous sacs that modify, store, and route products of the endoplasmic reticulum
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vacuoles
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carry out hydrolysis; food vacuole: fuse w/ lysosome to digest food; contractile vacuole: pump excess water out of cell; central vacuole "tonoplast": in plant cells, reserves important organic compounds, cell’s main repository of inorganic ions, disposal sires for metabolic by-products, pigment, protection, growth of plant
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plasma membrane
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Functions as a selective barrier; passage of oxygen, nutrients, and waste; encloses the cell
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nucleus
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the cell’s control center that contains most genes
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nucleolus
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a nonmembranous organelle that synthesizes rRNA and ribosomes
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Ribosomes
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nonmembranous organelles that make proteins. Contain ribosomal RNA and protein. Free ribosomes are found in the cytosol. Bound ribosomes are attached to the outside of the ER
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mitochondria
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semi-autonomous organelles that grow and reproduce within the cell, sites of cellular respiration, create ATP. Their membrane proteins are made by free ribosomes. It is enclosed by two membranes that are both phosolipids bilayers with proteins.
i. Intermembrane space: narrow region between inner and outer membranes ii. Mitochondrial matrix: contains enzymes, mitochondrial DNA, and ribosomes |
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Peroxisome
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an oxidative organelle that imports proteins. It has a single membrane and contains enzymes that transfer hydrogen from various substrates to oxygen, producing H2O2. Some use oxygen to break down fatty acids into smaller molecules that can be transported to mitochondria and used as fuel for cellular respiration
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glyoxysomes
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specialized perioxisomes found in fat-storing tissues of plants seeds that contain enzymes that initiate the conversion of fatty acids into sugar
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microvilli
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long, thin projections that increase surface area
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cytoskeleton
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a network of fibers extending throughout the cytoplasm. Support, motility, and regulation. Organizes the structures and activities of the cell. Motor proteins
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intermediate Filaments
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fibrous proteins supercoiled into thicker cables, bears tension. Functions to maintain cell shape, anchorage of nucleus and other organelles, forms nuclear lamina, framework of enite cytoskeleton. Keratin- skin, hair, nails
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microtubules
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hollow rods constructed from a globular protein, tubulin. Shape and support the cell and act as tracks for the movement of organelles equipped with motor proteins. Responsible for the separation of chromosomes during cell division
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centrosome
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“microtubules-organizing center.” compression-resisting girders of the cytoskeleton
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cilia and flagella
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locomotor appendages that protrude from some cells, with a core of microtubules sheathed in an extension of the plasma membrane “nine doublets” “9+2”, basal body: anchorage, dynein: motor protein
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Selective permeability
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a property of biological membranes that allows some substances to cross more easily than others.
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Hypotonic
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in comparing two solutions, referring to the one with a lower solute concentration
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amphipathic
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A molecule that has both a hydrophilic region and a hydrophobic region
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fluid mosaic model
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The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids
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integral proteins
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Typically a transmembrane protein with hydrophobic regions that completely spans the hydrophobic interior of the membrane
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peripheral proteins
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a protein appendage loosely bound to the surface of a membrane and not embedded in the lipid bilayer
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transport proteins
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A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane
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diffusion
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The spontaneous tendency of a substance to move down its concentration gradient from a more concentrated to a less concentrated area
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concentration gradient
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an increase or decrease in the density of a chemical substance in an area. Cells often maintain concentration gradients of ions across their membranes. When a gradient exists, the ions or other chemical substances involved tend to move from where they are more concentrated to where they are less concentrated
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passive transport
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The diffusion of a substance across a biological membrane
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endocytosis
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The cellular intake of macromolecules and particulate substances by localized regions of the plasma membrane that surround the substance and pinch off to form an intracellular vesicle inside the cell
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hypertonic
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in comparing two solutions, referring to the one with a greater solute concentration
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membrane potential
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the charge difference between a cell’s cytoplasm and the extracellular fluid, due to the differential distribution of ions. Membrane potential affects the activity of excitable cells and the transmembrane movement of all charged substances
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isotonic
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having the same solute concentration as another solution
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osmoregulation
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The regulation of solute and water concentrations in body fluids by organisms living in hyperosmotic, hypoosmotic, and terrestrial environments
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osmosis
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The diffusion of water across a selectively permeable membrane
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turgid
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Very firm. A walled cell become turgid if it has a greater solute concentration than its surroundings, resulting in entry of water.
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plasmolysis
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A phenomenon in walled cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall when the cell loses water to a hypertonic environment
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facilitated diffusion
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the spontaneous passage of molecules and ions, bound to specific carrier proteins, across a biological membrane down their concentration gradients
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gated channels
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a protein channel in a cell membrane that opens or closes in response to a particular stimulus
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active transport
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the movement of a substance across a biological membrane against its concentration or electrochemical gradient with the help of energy input and specific transport proteins
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sodium potassium pump
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- a special transport protein in the plasma membrane of animal cells that transports sodium out of the cell and potassium into the cell against their concentration gradients
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electrochemical gradient
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The diffusion gradient of an ion, representing a type of potential energy that accounts for both the concentration difference of the ion across a membrane and its tendency to move relative to the membrane potential
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proton pump
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An active transport mechanism in cell membranes that uses ATP to force hydrogen ions out of a cell, generating a membrane potential in the process
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cotransport
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The coupling of the downhill diffusion of one substance to the uphill transport of another against its own concentration gradient
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exocytosis
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The cellular secretion of macromolecules by the fusion of vesicles with the plasma membrane
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phagocytosis
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A type of endocytosis involving large, particulate substances, accomplished mainly by macrophages, neutrophils, and dendritic cells
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pinocytosis
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A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes
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receptor mediated endocytosis
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- The movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances
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Fermentation
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a catabolic process that creates a limited amount of ATP without the need for oxygen. It only involves glycolysis
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krebs cycle
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chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules to carbon dioxide; occurs within the mitochondria; the second major stage in cellular respiration
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anaerobic
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Lacking oxygen; referring to an organism, environment, or cellular process that lacks oxygen and may be poisoned by it
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cellular respiration
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The most prevalent and efficient catabolic pathway for the production of ATP, in which oxygen is consumed as a reactant along with the organic fuel; glycolysis, Citric Acid Cycle, and the Electron Transport Chain; • Organic Compounds + Oxygen → Carbon Dioxide + Water + Energy (ATP); • In total 38 ATP are yielded
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oxidative phosphorylation
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The production of ATP using energy derived from the redox reactions of an electron transport chain; takes place in mitochondria of cell
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alcohol fermentation
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conversion of pyruvate to carbon dioxide and ethyl alcohol
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redox reaction
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chemical process involving the transfer of one or more electrons from one reactant to another
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Substrate-level phosphorylation
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adds a phosphate directly to ADP to make ATP by using specialized enzymes; takes place in cytosol
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lactic acid fermentation
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conversion of pyruvate to lactate with no release of carbon dioxide
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oxidation
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loss of electrons from a substance involved in a redox reaction
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acetyl CoA
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entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme; formed during the breakdown of glucose by adding a two-carbon fragment to a carrier molecule
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facultative anaerobe
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organism that makes ATP by aerobic respiration if oxygen is present but that switches to fermentation under anaerobic conditions
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reduction
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Addition of electrons to a substance involved in a redox reaction
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cytochrome (cyt)
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small protein found loosely associated with the inner membrane of the mitochondrion. It is a soluble protein and is an essential component of the electron transfer chain. It is capable of undergoing oxidation and reduction. It also plays an important role in the transfer of electrons
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reducing agent
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electron donor in the redox reaction.
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ATP synthase
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a general term for an enzyme that can synthesize ATP from ADP and inorganic phosphate by utilizing some form of energy; ADP+ Pi ----> ATP
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oxidizing agent
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electron acceptor in the redox reaction
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chemiosmosis
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process by which ATP is produced in the inner membrane of a mitochondrion. The electron transport system transfers protons from the inner compartment to the outer; as the protons flow back to the inner compartment, the energy of their movement is used to add phosphate to ADP, forming ATP
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NAD+
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coenzyme present in all cells that helps enzymes transfer electrons during the redox reactions of metabolism
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proton motive force
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potential energy that is generated from the pumping of hydrogen ions across biological membranes during chemiosmosis
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glycolysis
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the splitting of glucose into pyruvate. Glycolysis is the one metabolic pathway that occurs in all living cells, serving as the staring point for fermentation or aerobic respiration; 2 ATP made
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aerobic
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containing or requiring oxygen
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Photosynthesis
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the conversion of light energy to chemical energy that is stored in glucose or other organic compounds; occurs in plants, algae, and certain prokaryotes; 6CO2 + light energy + 12H2O → 6O2 + C6H12O6 (glucose)
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Autotrophs
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An organism that obtains organic food molecules without eating other organisms or substances derived from other organisms. Autotrophs use energy from the sun or from the oxidation of inorganic substances to make organic molecules from inorganic one
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heterotrophs
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An organism that obtains organic food molecules by eating other organisms or their by-products
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absorption spectrum
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a graph plotting a pigment's light absorption versus wavelength
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chlorophyll a
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A type of blue-green photosynthetic pigment that participates directly in the light reactions
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chlorophyll b
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A type of yellow-green accessory photosynthetic pigment that transfers energy to chlorophyll a
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carotenoids
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An accessory pigment, either yellow or orange, in the chloroplasts of plants. By absorbing wavelengths of light that chlorophyll cannot, carotenoids broaden the spectrum of colors that can drive photosynthesis
|
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photo system
|
Consists of a reaction center surrounded by light harvesting complexes
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photophosphorylation
|
The process of generating ATP from ADP and phosphate by means of a proton-motive force generated by the thylakoid membrane of the chloroplast during the light reactions of photosynthesis
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carbon fixation
|
The initial incorporation of carbon into organic compounds in the chloroplast before the Calvin cycle occurs
|
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visible light
|
That portion of the electromagnetic spectrum detected as various colors by the human eye, ranging in wavelength from about 380 nm to about 750 nm
|
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photons
|
Discrete particles with a fixed quantity of energy
|
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cyclic flow of electrons
|
- Uses photosystem I but not photosystem II
- "Short circuit" - The electrons cycle back from ferredoxin to a P700 chlorophyll in the PS I reaction center. - There is no production of NADPH and no release of oxygen. Does, however, generate ATP. |
|
chlorophyll
|
- Green pigment within plant cells that absorbs light energy from the sun
- Found mainly in mesophyll cells |
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glyceraldehyde 3-phophate (G3P)
|
The carbohydrate produced directly from the Calvin cycle
|
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mesophylll
|
tissue on the interior of the leaf
|
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rubisco
|
The Calvin cycle enzyme that adds CO2 to ribulose bisphosphate (carbon fixation)
|
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stomata
|
- Small pores where CO2 enters and leaves the cell
|
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action spectrum
|
- Profiles the effectiveness of different wavelengths of radiation in driving photosynthesis
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C3 plants
|
- A plant that uses the Calvin cycle for the initial steps that incorporate CO 2 into organic material, forming a three–carbon compound as the first stable intermediate
|
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stroma
|
- Dense fluid within the chloroplast
- Where the Calvin cycle takes place |
|
photorespiration
|
- A metabolic pathway that consumes oxygen, releases carbon dioxide, generates no ATP, and decreases photosynthetic output; generally occurs on hot, dry, bright days, when stomata close and the oxygen concentration in the leaf exceeds that of carbon dioxide
|
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light reactions
|
- The steps in photosynthesis that occur on the thylakoid membranes of the chloroplast and that convert solar energy to the chemical energy of ATP and NADPH, evolving oxygen in the process
|
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C4 plants
|
- A plant that prefaces the Calvin cycle with reactions that incorporate CO 2 into a four–carbon compound, the end product of which supplies CO 2 for the Calvin cycle
|
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calvin cycle
|
- The second of two major stages in photosynthesis (following the light reactions), involving atmospheric CO 2 fixation and reduction of the fixed carbon into carbohydrate
|
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NADP+
|
- Electron acceptor used in photosynthesis
- Is produced by the light reactions by means of reduction |
|
reaction center
|
- Has two special chlorophyll a molecules that uses light energy to boost an electron towards the primary electron acceptor
|
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primary electron acceptor
|
- A specialized molecule sharing the reaction center with the pair of reaction–center chlorophyll a molecules; it accepts an electron from one of these two chlorophylls
|
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PEP carboxylase
|
- An enzyme that adds CO2 to phosphoenolpyruvate (PEP), forming the four–carbon product oxaloacetate
|
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photosystem I
|
- One of two light–capturing units in a chloroplast′s thylakoid membrane; it has two molecules of P700 chlorophyll a at its reaction center
|
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non cyclic electron flow
|
A route of electron flow during the light reactions of photosynthesis that involves both photosystems and produces ATP, NADPH, and oxygen. The net electron flow is from water to NADP+
|
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cell cycle
|
an ordered sequence of events in the life of a eukaryotic cell, from its origin in the division of a parent cell until its own division into two; composed of the M, G 1 , S, and G 2 phases
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chromosomes
|
are long pieces of DNA found in the center (nucleus) of cells. DNA is the material that holds genes. It is considered the building block of the human body
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kinetochore
|
A specialized region on the centromere that links each sister chromatid to the mitotic spindle
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metastasis
|
The spread of cancer cells to locations distant from their original site
|
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mitotic spindle
|
An assemblage of microtubules and associated proteins that is involved in the movements of chromosomes during mitosis
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cell division
|
reproduction of cells
|
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interphase
|
The period in the cell cycle when the cell is not dividing. During interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. Interphase accounts for 90% of the cell cycle
|
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metaphase
|
The third stage of mitosis, in which the spindle is complete and the chromosomes, attached to microtubules at their kinetochores, are all aligned at the metaphase plate.
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mitosis
|
A process of nuclear division in eukaryotic cells conventionally divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase. Mitosis conserves chromosome number by equally allocating replicated chromosomes to each of the daughter nuclei
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genome
|
All of the genetic information, the entire genetic complement, all of the hereditary material possessed by an organism
|
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G1 phase
|
(1st gap) The first growth phase of the cell cycle, consisting of the portion of interphase before DNA synthesis begins
|
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cleavage furrow
|
The first sign of cleavage in an animal cell; a shallow groove in the cell
|
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anaphase
|
The fourth stage of mitosis, in which the chromatids of each chromosome have separated and the daughter chromosomes are moving to the poles of the cell
|
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somatic cell
|
Any cell in a multicellular organism except a sperm or egg cell
|
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S phase
|
The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated
|
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cell plate
|
A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis
|
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cyclin
|
A regulatory protein whose concentration fluctuates cyclically
|
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gametes
|
A reproductive cell or sex cell that contains the haploid set of chromosomes, e.g. sperm cell and egg cell/ovum
|
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G2 phase
|
The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs
|
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binary fission
|
The type of cell division by which prokaryotes reproduce. Each dividing daughter cell receives a copy of the single parental chromosome
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cytokinesis
|
The division of the cytoplasm to form two separate daughter cells immediately after mitosis
|
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tumor
|
a mass of abnormal cells within otherwise normal tissue
|
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chromatin
|
the structure of the chromosome when a cell is not dividing, even as the DNA is duplicating for cell division, long and thin fiber, during cell division ~ condenses
|
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prophase
|
The first stage of mitosis, in which the chromatin is condensing and the mitotic spindle begins to form, but the nucleolus and nucleus are still intact
|
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M phase
|
(mitotic phase) the phase of the cell cycle that includes mitosis and cytokinesis
|
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benign tumor
|
A mass of abnormal cells that remains at the site of origin
|
|
sister chromatid
|
Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II
|
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prometaphase
|
The second stage of mitosis, in which discrete chromosomes consisting of identical sister chromatids appear, the nuclear envelope fragments, and the spindle microtubules attach to the kinetochores of the chromosomes
|
|
telophase
|
The fifth and final stage of mitosis, in which daughter nuclei are forming and cytokinesis has typically begun
|
|
malignant tumor
|
a cancerous tumor that is invasive enough to impair the functions of one or more organs
|
|
centromere
|
The centralized region joining two sister chromatids
|
|
metaphase
|
The third stage of mitosis, in which the spindle is complete and the chromosomes, attached to microtubules at their kinetochores, are all aligned at the metaphase plate
|
|
cyclin-dependent kinase (Cdk)
|
A protein kinase that is active only when attached to a particular cyclin.
|
|
hereditary
|
transmission of traits from one generation to the next
|
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variation
|
offspring differ somewhat from parents in appearance; independent assortment, crossing over, random fusion of gametes, mutations
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genetics
|
Scientific study of heredity and hereditary variation
|
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gene
|
A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA
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|
asexual reproduction
|
A type of reproduction involving only one parent that produces genetically identical offspring by budding or by the division of a single cell or the entire organism into two or more parts
|
|
sexual reproduction
|
Two parents give rise to offspring that have unique combinations of genes inherited from the gametes of the two parents
|
|
alteration of generation
|
A life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte, characteristic of plants and some algae
|
|
homologous chromosomes
|
pair of chromosomes; one paternal one maternal
|
|
autosomal chromosomes
|
22 pairs; not involved in determining sex
|
|
sex chromosomes
|
1 pair; XX OR XY
|
|
zygote
|
The diploid product of the union of haploid gametes in conception (a fertilized egg)
|
|
fertilization
|
The union of haploid gametes to produce a diploid zygote
|
|
karyotope
|
A display of the chromosome pairs of a cell arranged by size, number, shape, and type
|
|
meiosis
|
A two-stage type of cell division in sexually reproducing organisms that results in cells with half the chromosome number of the original cell
|
|
interphase
|
The period in the cell cycle when the cell is not dividing. During interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. Interphase accounts for 90% of the cell cycle
|
|
prophase I
|
• Longest phase
• Chromosomes condense • Homologous chromosomes loosely pair • Crossing-Over- DNA molecules in nonsister chromatids break at corresponding places and then rejoin to the other’s DNA • Synapsis- Portions of homologous chromosomes and genes cross back and forth • Tetrad Formation- Once the synaptonemal complex dissembles, each chromosome pair becomes visible in the microscope as a tetrad, which is a group of 4 chromatids • Chiasma (chiasmata=plural)- Criss-crossed regions where crossing over has occurred, which holds the homologous chromosomes together • Movement of centrosomes, formation of spindle microtubules, breakdown of the nuclear envelope, and the dispersal of nucleoli • The kinetochores of each homologue attach to microtubules from one pole or the other • Homologous pairs move toward the metaphase plate |
|
metaphase I
|
• Tetrads align at the metaphase plate
• Each of the two homologous chromosomes in the tetrad are attached to kinetochore microtubules from each pole |
|
anaphase I
|
• Homologous chromosomes pull apart
• Chromosomes move toward the poles guided by the spindle apparatus • Separation accomplished by • Disassembly of kinetochore microtubules • Elongation by nonkinetochore microtubules |
|
telophase I
|
• Chromosomes reach opposite poles
• Each cell has a haploid number of chromosomes, but is still composed of sister chromatids |
|
cytokinesis (for meiosis)
|
• Formation of two haploid daughter cells
• Animal Cells- Form a cleavage furrow • Plant Cells- Form a cell plate • Sometimes, the chromosome decondense and the nuclear envelope and nucleoli re-form |
|
interkinesis
|
• Nuclear envelopes may form
• No replication of chromosomes takes place |
|
prophase II
|
• Spindle apparatus forms
• Chromosomes are still composed of sister chromatids that are moving toward the metaphase II plate |
|
metaphase II
|
• Sister chromatids align at the metaphase II plate
• Because of crossing over in meiosis I, the two sister chromatids of each chromosome are not genetically identical |
|
anaphase II
|
• Sister chromatids separate
• Moving now as two individual chromosomes toward opposite poles |
|
telophase II
|
• Each cell has a haploid number of chromosomes
• Nuclei forms and the chromosomes begin to decondense |
|
character
|
Heritable feature that varies among individuals ex. Flower color
|
|
Trait
|
Variant for a character ex. Purple or white flowers
|
|
true-breeding
|
Offspring of the same variety by self-pollinating (plants)
|
|
hybridization
|
Mating, or crossing of two true-breeding varieties
|
|
monohybrid cross
|
A cross between parents who are heterozygous for one character
|
|
P generation
|
parental generation
|
|
F1 Generation
|
first filial generation
|
|
F2 Generation
|
second filial generation
|
|
alleles
|
Alternative versions of a gene
|
|
dominant allele
|
determines the organism's appearance
|
|
recessive allele
|
No noticeable effect on the organisms appearance
|
|
law of segregation
|
The two alleles for a heritable character separate during gamete formation and end up in different gametes
|
|
homozygous
|
identical alleles for a character
|
|
heterozygous
|
two different alleles for a character
|
|
phenotype
|
Physical appearance, traits
|
|
test cross
|
Breeding of a recessive homozygote with an organism of dominant phenotype but unknown genotype
|
|
genotype
|
genetic makeup
|
|
law of independent assortment
|
Each pair of alleles segregates independently of other pairs of alleles during gamete formation
|
|
incomplete dominance
|
Dominance falls in the middle of two alleles ex. Pink flowers from red and white
|
|
complete dominance
|
One allele has complete dominance over the other
|
|
codominance
|
Two alleles both affect the phenotype in separate distinguishable ways ex. Cat that appears blue but up close hair alternates yellow and green
|
|
multiple alleles
|
Most genes exist in populations in more than two allelic forms ex. ABO blood type
|
|
pleiotropy
|
Genes have multiple phenotypic effects, sickle-cell
|
|
epistasis
|
A gene at one locus alters the phenotypic expression of a gene at a second locus
|
|
polygenic inheritance
|
Additive effect of two or more genes on a single phenotypic character (opposite of pleiotropy)
|
|
norm of reaction
|
Phenotypic range
|
|
dihybrid cross
|
is a cross between F1 offspring (first generation offspring) of two individuals that differ in two traits of particular interest.
|
|
carriers
|
is a person or other organism that has inherited a genetic trait or mutation. Has it but may not express it.
|
|
cystic fibrosis
|
Caused by a mutation in the gene. It is normally supposed to code for a membrane protein that function in chlorideion transport between certain cells and the extracellular fluid. These transport tubes are absent in children who inherit two recessive alleles for cystic fibrosis. High concentration of chloride, mucus coats cells.
|
|
tay-sachs disease
|
Inherited disorder in humans. Caused by a genetic defect in a single gene with one defective copy of that gene inherited from each parent. The disease occurs when harmful quantities of gangliosides accumulate in the nerve cells of the brain, eventually leading to the premature death of those cells. Results in poor mental and physical state.
|
|
sickle cell disease
|
Cause by the substitution of a single amino acid in the hemoglobin protein of red blood cells. Clots vessels, example of pleiotrophy.
|
|
huntington's disease
|
Incurable neurodegenerative genetic disorder that affects muscle coordination and some cognitive functions. The disease is caused by a dominant mutation on either of the two copies of a specific gene, located on chromosome 4.
|
|
chromosome theory of inheritance
|
a basic principle stating that genes are located on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns
|
|
linkage map
|
a genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes
|
|
polyploidy
|
a chromosomal alteration in which the organism possesses more than two complete chromosome sets
|
|
parental type
|
an offspring with a phenotype that matches one of the parental phenotypes
|
|
deletion
|
a deficiency in a chromosome resulting from the loss of a fragment through breakage
|
|
wild type
|
an individual with the normal (most common) phenotype
|
|
recombinants
|
an offspring whose phenotype differs from that of the parents
|
|
duplication
|
an aberration in chromosome structure due to fusion with a fragment from a homologous chromosome
|
|
mutant phenotype
|
an offspring with a rare change in the DNA of a gene, creating genetic diversity
|
|
hemophilia
|
a human genetic disease caused by a sex-linked recessive allele; characterized by excessive bleeding following injury
|
|
inversion
|
an aberration in chromosome structure resulting from reattachment in a reverse orientation of a chromosomal fragment to the chromosome from which the fragment originated
|
|
sex linked gene
|
a gene located on a sex chromosome
|
|
linked genes
|
genes located close enough together on a chromosome to be usually inherited together
|
|
non disjunction
|
an error in meiosis or mitosis, in which both members of a pair of homologous chromosomes or both sister chromatids fail to move apart properly
|
|
down syndrome
|
a human genetic disease caused by presence of an extra chromosome 21; characterized by mental retardation and heart and respiratory defects
|
|
genetic recombination
|
general term for the production of offspring that combine traits of the two parents
|
|
aneuploidy
|
a chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number
|
|
fragile X syndrome
|
genetic condition involving changes in part of the x chromosome; most common form of inherited mental retardation in males and a significant cause of mental retardation in females
|
|
phages
|
A virus that infects bacteria; also called a bacteriophage
|
|
DNA polymerase
|
the enzyme that adds nucleotides to the end of the elongated template strand
|
|
primase
|
the enzyme that joins RNA nucleotides to the primer section of the DNA so that the DNA primase can then start to code for nucleotides
|
|
nuclease
|
An enzyme that hydrolyzes DNA and RNA into their component nucleotides
|
|
double helix
|
the shape DNA is in. the two strands are counter parallel of each other.
|
|
leading s trand
|
the strand that is continuously elongated working toward the replication fork in the 5’-> 3’ direction
|
|
helicase
|
the enzyme that untwists the double helix at the replication fork
|
|
excision repair
|
the nuclease cuts (or excises) damaged parts of the strand and then ligase & polymerase adds more
|
|
semiconservative model
|
the model that says half of the original strand is used in the daughter strand.
|
|
lagging strand
|
the strand that is working away from the replication fork, still in the 5’-> 3’ direction. The fragments of the lagging strand are called Okazaki fragments
|
|
telomerase
|
catalyzes the lengthening of telomeres in eukaryotic germ cells, compensating for the shortening that occurs during DNA replication
|
|
single strand binding protein
|
the protein that keeps the two strands from coming back together after helicase separates them.
|
|
origins of replication
|
The replication of a DNA molecule begins at special sites called origins of replication
|
|
DNA
|
the genetic building block of this class. So help you if you don’t know what DNA is
|
|
ligase
|
the enzyme that joins the sugar phosphate backbones of the Okazaki fragments , forming a single new DNA strand
|
|
protein
|
the substance that DNA codes to made.
|
|
replication fork
|
the place in the DNA where the two strands are split and coded.
|
|
primer
|
the initial nucleotide chain that is short , short stretch of RNA with an available 3’ end
|
|
one gene one polypeptide
|
- Each gene in DNA will code for one and only one specific polypeptide
|
|
transcription
|
- The process by which the cell makes a strand of pre-mRNA from a single strand of DNA
|
|
messenger RNA (mRNA)
|
A type of RNA, synthesized from DNA, that attaches to ribosomes in the cytoplasm and specifies the primary structure of a protein
|
|
terminator
|
- A special sequence of nucleotides in DNA that marks the end of a gene. It signals RNA polymerase to release the newly made RNA molecule, which then departs from the gene
|
|
translation
|
The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of languagefrom nucleotides to amino acids
|
|
initiation
|
(translation) a small ribosomal subunit binds to the 5' end of the mRNA synthesized in transcription. The anticodon that corresponds to the start codon AUG then binds to the start codon
|
|
elongation
|
(translation) each codon is read by the ribosome and paired with the corresponding tRNA, moving down the mRNA and each time adding an amino acid to the polypeptide sequence
|
|
termination
|
(translation) When the ribosome reaches one of these stop codons, it attaches a release factor which then accepts a water molecule, thereby hydrolyzing the polypeptide chain and causing it to break off
o Stop codons: UGA, UAA, UAG |
|
RNA processing
|
- The process that pre-mRNA must undergo before it can be used in translation
- A 5' cap is added to the beginning of the strand and a poly (A) tail to the 3' end after the introns are cut out |
|
triplet code
|
- A group of 3 DNA nucleotides that are read three as a time because they code for a specific codon
|
|
template strand
|
- The DNA strand that provides the template for ordering the sequence of nucleotides in an RNA transcript
|
|
codon
|
A three-nucleotide sequence of DNA or mRNA that specifies a particular amino acid or termination signal; the basic unit of the genetic code.
|
|
transcription unit
|
- The region of a DNA molecule that is transcribed into an RNA molecule
|
|
transcription factors
|
- A regulatory protein that binds to DNA and stimulates transcription of specific genes
|
|
primary transcript
|
- An initial RNA transcript; also called pre–mRNA when transcribed from a protein–coding gene
|
|
TATA box
|
- A promoter DNA sequence crucial in forming the transcription initiation complex
|
|
5' cap
|
- The 5′ end of a pre–mRNA molecule modified by the addition of a cap of guanine nucleotide
|
|
poly (A) tail
|
- The modified end of the 3′ end of an mRNA molecule consisting of the addition of some 50 to 250 adenine nucleotides
|
|
RNA splicing
|
The removal of noncoding portions of the RNA molecule after initial synthesis by spliceosomes
|
|
intron
|
- A noncoding, intervening part of pre-mRNA that is taken out by spliceosomes
|
|
domain
|
An independently folding part of a protein
|
|
transfer RNA (tRNA)
|
An RNA molecule that functions as an interpreter between nucleic acid and protein language by picking up specific amino acids and recognizing the appropriate codons in the mRNA
|
|
anticodon
|
- a group of 3 RNA nucleotides that are attaches to tRNA and will bond with a certain codon, allowing the tRNA to donate its amino acid
|
|
wobble
|
- A violation of the base–pairing rules in that the third nucleotide (5′ end) of a tRNA anticodon can form hydrogen bonds with more than one kind of base in the third position (3′ end) of a codon
|
|
aminoacyl-tRNA
|
- tRNA that has an amino acid attaches to it
|
|
sysnthetases
|
- An enzyme that joins each amino acid to the correct tRNA
|
|
ribsomal RNA (rRNA)
|
- Is synthesized from rRNA genes on the DNA, and then joined with proteins to make ribosomes, which are directly used in translation
|
|
A site
|
- The site in proteins where a tRNA first attaches to a codon
|
|
P site
|
- The site in ribosomes where the amino acid of tRNA is bonded to the adjacent amino acid by means of the large ribosomal subunit
|
|
E site
|
- The site in ribosomes where tRNA exists after it has donated its amino acid
|
|
polyribosome
|
- A combination of several ribosomes attached to one messenger RNA molecule
|
|
point mutation
|
- A change in a gene at a single nucleotide pair
- Silent mutations: they have no effect on the encoded protein |
|
exon
|
- After RNA processing, they are the segments of RNA left in the mRNA
- Joined together by spliceosomes |
|
base pair substitution
|
- the replacement of one nucleotide and its partner with another pair of nucleotides
|
|
missesnse mutation
|
- the altered codon still codes for an amino acid and thus makes sense
|
|
nonsense mutation
|
- A mutation in which the change in a codon then codes for a stop codon
- causes translation to be terminated prematurely |
|
insertion
|
- A mutation involving the addition of one or more nucleotide pairs to a gene
|
|
deletion
|
- A mutational loss of one or more nucleotide pairs from a gene
|
|
frameshift mutation
|
- A mutation occurring when the number of nucleotides inserted or deleted is not a multiple of three, resulting in the improper grouping of the following nucleotides into codons
|
|
mutagens
|
- A chemical or physical agent that interacts with DNA and causes a mutation
|
|
spliceosome
|
- A complex assembly that interacts with the ends of an RNA intron in splicing RNA, releasing the intron and joining the two adjacent exons
|
|
snRNP
|
- Small nuclear ribonucleoprotein
- Binds with proteins to form a spliceosome - Tells the spliceosome where to cut the pre-mRNA |
|
RNA polymerase
|
- Travels along the DNA, attached to the beginning of a region of DNA called the promoter by protein transcription factors
- Untwists the DNA double helix, traveling along the DNA from 3; to 5', pairing RNA nucleotides that compliment the DNA strand |
|
reading frame
|
- The way a cell groups the mRNA nucleotides into codons
|
|
capsid
|
the protein shell that encloses a viral genome; it may be rod-shaped, polyhedral, or more complex in shape
|
|
provirus
|
viral DNA that inserts into a host genome
|
|
transformation
|
a change in genotype and phenotype due to the assimilation of external DNA by a cell
|
|
operator
|
in prokaryotic DNA, a sequence of nucleotides near the start of an operon to which an active repressor can attach; the binding of the repressor prevents RNA polymerase from attaching to the promoter and transcribing the genes of the operon
|
|
viral envelope
|
a membrane that cloaks the capsid that in turn encloses a viral genome
|
|
retrovirus
|
an RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome; an important class of cancer-causing viruses
|
|
transduction
|
a DNA transfer process in which phages carry bacterial genes from one host cell to another
|
|
operon
|
a unit of genetic function common in bacteria and phages, consisting of coordinately regulated clusters of genes with related functions
|
|
reverse transcriptase
|
an enzyme encoded by some certain viruses (retroviruses) that uses RNA as a template for DNA synthesis
|
|
conjugation
|
in prokaryotes, the direct transfer of DNA between two cells that are temporarily joined
|
|
host range
|
the limited range of host cells that each type of virus can infect and parasitize
|
|
HIV
|
human immunodeficiency virus; the infectious agent that causes AIDS; HIV is a retrovirus
|
|
F factor
|
a fertility factor in bacteria; a DNA segment that confers the ability to form pili for conjugation and associated functions required for the transfer from donor to recipient; it may exist as a plasmid or be integrated into the bacterial chromosome
|
|
regulatory gene
|
a gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes
|
|
lytic cycle
|
a type of viral replication cycle resulting in the release of new phages by lysis (and death) of the host cell
|
|
AIDS
|
acquired immunodeficiency syndrome; the name of the late stages of HIV infection, defined by a specified reduction of T cells and the appearance of characteristic secondary infections
|
|
repressor
|
a protein that suppresses the transcription of a gene
|
|
corepressor
|
a small molecule that cooperates with a repressor protein to switch on operon off
|
|
virulent
|
a term describing a pathogen against which a plant has little specific defense
|
|
vaccine
|
a harmless variant or derivative of a pathogen that stimulates a host’s immune system to mount defenses against the pathogen
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F plasmid
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the plasmid form of the F factor
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inducer
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a specific small molecule that inactivates the repressor in an operon
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lysogenic cycle
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a phage replication cycle in which the viral genome becomes incorporated into the bacterial host chromosome as a prophage and does not kill the host
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viron
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a single virus particle
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R plasmid
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a bacterial plasmid carrying genes that confer resistance to certain antibiotics
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cyclic amp (cAMP)
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cyclic adenosine monophosphate, a ring-shaped molecule made from ATP that is a common intracellular signaling molecule (second messenger) in eukaryotic cells; also a regulator of some bacterial operons
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temperate virus
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a virus that can reproduce without killing the host
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prion
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an infectious form of protein that may increase in number by converting related proteins to more prions
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transposon
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a transposable genetic element that moves within a genome by means of a DNA intermediate
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cAMP receptor protein
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regulatory protein in bacteria; binds cAMP, which causes a conformational change that allows the protein to bind tightly to a specific DNA sequence in the promoters of the genes it controls
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prophage
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a phage genome that has been inserted into a specific site on the bacterial chromosome
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nucleoid
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a dense region of DNA in a prokaryotic cell
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insertion sequence
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the simplest kind of transposable element, consisting of inverted repeats of DNA flanking a gene for transposase, the enzyme that catalyzes transposition
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