Shared Flashcard Set

Details

LIFE 102 Exam 1
For exam 1
165
Biology
Undergraduate 1
09/14/2011

Additional Biology Flashcards

 


 

Cards

Term
Atom`
Definition
The smallest unit of matter that retains the properties of an element.
Term
pH`
Definition
A measure of hydrogen ion concentration equal to -log[H+] and ranging in value from 0 to 14.
Term
Neutron`
Definition
A subatomic particle having no electrical charge, found in the nucleus of an atom.
Term
Buffer`
Definition
A solution that contains a weak acid and its corresponding base. A buffer minimizes changes in pH when acids or bases are added to the solution.
Term
Proton`
Definition
A subatomic particle with a single positive electrical charge, found in the nucleus of an atom.
Term
Hydroxyl group`
Definition
A chemical group consisting of an oxygen atom joined to a hydrogen atom. Molecules possessing this group are soluble in water and are called alcohols
Term
electron`
Definition
A subatomic particle with a single negative charge.
Term
Carbonyl group`
Definition
A chemical group present in aldehydes and ketones and consisting of a carbon atom double bounded to an oxygen atom.
Term
element`
Definition
Any substance that cannot be broken down to any other substance by chemical reactions.
Term
Aldehyde`
Definition
any of a class of organic compounds containing the group −CHO, which yields acids when oxidized and alcohols when reduced.
Term
atomic number`
Definition
The number of protons in the nucleus of an atom, subscipt to the left of the elemental symbol.
Term
ketone`
Definition
any of a class of organic compounds containing a carbonyl group, CO, attached to two alkyl groups, as CH 3 COCH 3 or CH 3 COC 2 H 5
Term
atomic weight`
Definition
weight of an element
Term
molecular weight`
Definition
weight of a molecule of an element
Term
monomer`
Definition
The subunit that serves as the building block of a polymer.
Term
solute`
Definition
A substance that is dissolved in a solution.
Term
Dalton`
Definition
A measure of mass for atoms and subatomic particles, the same as the atomic mass unit.
Term
Solvent`
Definition
The dissolving agent of a solution. Water is the most versatile solvent known.
Term
Carboxyl group`
Definition
A chemical group present in organic acids and consisting of a single carbon atom double bonded to an oxygen atom and also bonded to a hydroxyl group.
Term
peptide bond`
Definition
The covalent bond between the carboxyl group on one amino acid and the amino group on another, formed by a dehydration reaction.
Term
isotope`
Definition
One of several atomic forms of an element, each with the same number of protons but a different number of neutrons, thus differing in atomic mass.
Term
amino group
`
Definition
A chemical group consisting of a nitrogen atom bonded to two hydrogen atoms; can act as a base in a solution, accepting a hydrogen ion and acquiring a charge of 1+.
Term
radioactive isotope
`
Definition
An isotope that is unstable, the nucleus decays spontaneously giving off dettectable particles and energy.
Term
valence shell`
Definition
The outermost energy shell of an atom, contatining valance electrons.
Term
hydrophobic interations`
Definition
A type of weak chemical interaction caused when molecules that do not mix with water coalesce to exclude water.
Term
sulfhydryl group`
Definition
A chemical group consisting of a sulfur atom bonded to a hydrogen atom.
Term
covalent bond`
Definition
A type of strong chemical bond in which two atoms share one or more pairs of valence electrons.
Term
phosphate group`
Definition
A chemical group consisting of a phosphorus atom bonded to four oxygen atoms, important in energy transfer.
Term
eukaryotic` [cell]
Definition
A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with eukaryotic cells (protits, plants, fungi, and animals) are called eukaryotes.
Term
polar covalent bond`
Definition
A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.
Term
disaccharide`
Definition
A double sugar, consisting of two monosaccharides joined by a glycosidic linkage formed by a dehydration reaction.
Term
polysaccharide`
Definition
A polymer of many monosaccharides, formed by dehydration reactions.
Term
ionic bond`
Definition
A chemical bond resulting from the attraction between oppositely charged ions.
Term
glycosidic linkage`
Definition
A covalent bond formed between two monosaccharides by a dehydration reaction.
Term
ion`
Definition
An atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge.
Term
steriod`
Definition
A type of lipid characterized by a carbon skeleton consisting of four fused rings with various chemical groups attached.
Term
hydrogen bond`
Definition
A type of weak chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule.
Term
acid`
Definition
A substance that increases the hydrogen ion concentration of a solution.
Term
base`
Definition
A substance that reduces the hydrogen ion concentration of a solution.
Term
carbohydrate`
Definition
A sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysccharides).
Term
nonpolar covalent bond`
Definition
A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity.
Term
polymer`
Definition
A long molecule consisting of many similar or identical monomers linked together by covalent bonds.
Term
prokaryotic [cell]`
Definition
A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with prokaryotic cells (bacteria and archaea) are called prokaryotes.
Term
mass number
Definition
The sum of the number of protons and neutrons in an atoms nucleus.
Term
electronegativity
Definition
The attraction of a given atom for the electrons of a covalent bond.
Term
Van der waals interactions
Definition
Weak attractions between molecules or parts of molecules that result from transient local partial charges.
Term
polar molecule
Definition
A molecule with an uneven distribution of charges in different regions of the molecule.
Term
cohesion
Definition
The linking together of like molecules, often by hydrogen bonds.
Term
adhesion
Definition
the clinging of one substance to another
Term
surface tension
Definition
a measure of how difficult it is to stretch or break the surface of a liquid
Term
celsius scale
Definition
A temperature scale that measures the freezing point of water at 0 degrees C and boiling at 100 deg C
Term
calorie (cal)
Definition
The amount of heat energy required to raise the temperature of 1g of water by 1 degree C.
Term
kilocalorie (kcal)
Definition
A thousand calories
Term
joule (J)
Definition
a unit of energy
Term
specific heat
Definition
the amount of heat that must be absorbed or lost for 1 g of a substance to change its temp by 1 deg C
Term
heat of vaporization
Definition
The quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state.
Term
evaporative cooling
Definition
The process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from the liquid to the gaseous state.
Term
solution
Definition
a liquid that is a homogeneous mixture of two or more substances
Term
solvent
Definition
the dissolving agent of a solution
Term
solute
Definition
a substance that is dissolved in a solution
Term
aqueous solution
Definition
A solution in which water is the solvent.
Term
hydrophilic
Definition
Having an affinity for water.
Term
colloid
Definition
A mixture made up of a liquid and particles that (because of their size) remain suspended rather than dissolved in that liquid.
Term
hydrophobic
Definition
Having no affinity for water, tending to coalesce and form droplets in water.
Term
molecular mass
Definition
the sum of the masses of all the atoms in a molecule, sometimes called molecular weight.
Term
mole(mol)
Definition
the number of grams of a substance that equals its molecular weight in daltons and contains Avogadros number of molecules.
Term
molarity
Definition
a common measure of solute concentration, referring to the number of moles of solute per liter of solution.
Term
hydrogen ion
Definition
A single proton with a charge of 1+...H+
Term
hydroxide ion
Definition
A water molecule that has lost a proton OH-
Term
hydronium ion
Definition
A water molecule that has an extra proton bought to it, H3O+, commonly represented as H+
Term
organic chemistry
Definition
the study of carbon compounds (organic compounds)
Term
hydrocarbons
Definition
An organic molecule consisting only of carbon and hydrogen.
Term
isomers
Definition
one of several compounds with the same molecular formula but different structures and therefore different properties.
Term
structural isomers
Definition
One of several compounds that have the same molecular formula but differ in the covalent arrangements of their atoms.
Term
cis-trans isomers
Definition
One of several compounds that have the same molecular formula and covalent bonds between atoms but differ in the spatial arrangements of their atoms owing to the inflexibility of double bonds
Term
enantiomers
Definition
One of two compounds that are mirror images of each other and that differ in shape due to the presence of asymmetric carbon.
Term
adenosine triphosphate (ATP)
Definition
An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. Used to drive endergonic reactions in cells.
Term
macromolecules
Definition
A giant molecule formed by the joining of smaller molecules.
Term
polymer
Definition
A long molecule consisting of many similar or identical monomers linked together by covalent bonds.
Term
monomers
Definition
The subunit that serves as the building block of a polymer.
Term
enzymes
Definition
A macromolecule serving as a catalyst, a chemical agent that increases the rate of a reaction without being consumed by the reaction. Most are proteins.
Term
dehydration reaction
Definition
A chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule.
Term
hydrolysis
Definition
A chemical reaction that breaks bonds between two molecules by the addition of water, function in dissasembly of polymers to monomers.
Term
carbohydrates
Definition
A sugar or one of its dimers or polymers.
Term
monosaccharide
Definition
the simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccs.
Term
starch
Definition
a storage polysaccharide in plants, consisting entirely of glucose monomers joined by a glycosidic linkage.
Term
glycogen
Definition
an extensively branched glucose storage polysaccharide found in the liver and muscle of animals, the animal equivalent of starch
Term
cellulose
Definition
A structural polysaccharide of plant cell walls, consisting of glucose monomers joined by glycosidic linkages.
Term
lipid
Definition
any of a group of large biological molecules, including fats, phospholipids, and steroids, that mix poorly, if at all, with water.
Term
phospholipid
Definition
A lipid made up of glycerol joined to two fatty acids and a phosphate group.
Term
steroid
Definition
a type of lipid characterized by a carbon skeleton consisting of four fused rings with various chemical groups attached.
Term
cholesterol
Definition
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, such as many hormones.
Term
polypeptide
Definition
A polymer of many amino acids linked together by peptide bonds.
Term
protein
Definition
A biologically functional molecule consisting of one or more polypeptides folded and coiled into a specific 3D structure.
Term
amino acid
Definition
An organic molecule possessing both a carboxyl and an amino group. Serve as the monomers of polypeptides.
Term
nucleoutide
Definition
the building block of nucleic acids, five carbon sugars covalently bonded to a nitrogenous base and one or more phosphate groups
Term
organelle
Definition
any of several membrane enclosed structures with specialized functions, suspended in the cytosol of euk cells.
Term
scanning electron microscope (SEM)
Definition
uses a beam to scan surface of sample
Term
transmission electron microscope (TEM)
Definition
can see inside the cell
Term
cell fractionation
Definition
The disruption of a cell and separation of its parts by centrifugation at successively higher speeds.
Term
cytosol
Definition
The semifluid portion of the cytoplasm.
Term
nucleoid
Definition
a non membrane bounded region in a prokaryotic cell where the DNA is concentrated.
Term
plasma membrane
Definition
the membrane at the boundary of every cell that acts as a selective barrier regulating the cells chemical composition.
Term
nucleolus
Definition
a specialized structure in the nucleus, consists of RNA
Term
ribosomes
Definition
A complex of rRNA and protein molecules that functions as a site of protein synthesis in the cytoplasm, consists of a large and a small subunit.
Term
nucleus
Definition
contains genetic material in the form of chromosomes
Term
nuclear envelope
Definition
euk cell, the double membrane that surrounds the nucleus
Term
nuclear lamina
Definition
a netlike array of protein filaments that lines the inner surface of the nuc. env. and helps maintain the shape of the nucleous.
Term
chromosomes
Definition
A cellular structure carrying genetic material, found in the nucleous of euk cells. Each consists of one very long DNA molecule and associated proteins.
Term
endomembrane system
Definition
The collction of membranes inside and surrounding a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles, includes the plasma membrane, the nuclear envelope, the smooth and rought ER, the golgi apparatus, lysosomes, vesicles, and vacuoles.
Term
vesicles
Definition
a membranous sac in the cytoplasm of a euk cell.
Term
endoplasmic reticulum (ER)
Definition
An extensive membranous network in eukaryotic cells, continuous with the outer nuclear membrane and composed of ribosome studded (rough) and ribosome free (smooth) regions.
Term
smooth ER
Definition
That portion of the endoplasmic reticulum that is free of ribosomes.
Term
rough er
Definition
That portion of the endoplasmic reticulum with ribosomes attached.
Term
glycoproteins
Definition
A protein with one or more covalently attached carbohydrates.
Term
transport vesicles
Definition
A small membranous sac in a euk cells cytoplasm carrying molecules produced by the cell.
Term
golgi apparatus
Definition
An organelle in euk cells consisting of stacks of flat membranous sacs that modify, store, and route products of the endoplasmic reticulum and synthesisze some products, notable noncellulose carbohydrates.
Term
lysosome
Definition
A membrane enclosed sac of hydrolytic enzymes found in the cytoplasm of animal cells and some protists.
Term
phagocytosis
Definition
A type of endocytosis in which large particulate substances or small organisms are taken up by a cell. It is carried out by some protists and by certain immune cells of animals.
Term
vacuoles
Definition
a membrane bounded vesicle whose specialized function varies in different kinds of cells.
Term
mitochondria
Definition
An organelle in euk cells that serves as the site of cellular respiration, uses oxygen to break down organic molecules and synthesize ATP.
Term
chloroplasts
Definition
An organelle found in plants and photosynthetic protists that absorbs sunlight and usese it to drive the synthesis of organic compounds from carbon dioxide and water.
Term
cristae
Definition
An infolding of the inner membrane of a mitochondrion. The inner membrane houses electron transport chains and molecules of the enzyme catalyzing the synthesis of ATP.
Term
mitochondrial matrix
Definition
The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the citric acid cycle, as well as ribosomes and DNA
Term
thylakoids
Definition
A flattened, membranous sac inside a chloroplast. Often exist in stacks called grana that are interconnected, their membranes contain molecular "machinery" used to convert light energy to chemical energy.
Term
granum
Definition
A stack of membrane bounded thylakoids in the chloroplast. Function in the light reactions of photosynthesis.
Term
stroma
Definition
the dense fluid within the chloroplast surrounding the thylakoid membrane and containing ribosomes an DNA
Term
plastids
Definition
One of a family of closely related organelles that includes chloroplasts, chromoplasts, and amyloplasts. Found in cells of photosynthetic euks.
Term
peroxisome
Definition
An organelle containing enzymes that transfer hydrogen atoms from various sustrates to oxygen producing and then degrading hydrogen peroxide.
Term
cytoskeleton
Definition
A network of microtubules, microfilaments, and intermediate filaments that extend throughout the cytoplasm and serve a variety of mechanical, transport, and signaling functions.
Term
motor proteins
Definition
A protein that interacts with cytoskeletal elements and other cell components, producing movement of the whole cell or parts of the cell.
Term
micotubules
Definition
A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all euk cells and is found in cilia and flagella.
Term
centrosome
Definition
A structure present in the cytoplasm of animal cells that functions as a microtubule organizing center and is important during cell division. Has two centrioles.
Term
centrioles
Definition
A structure in the centrosome of an animal cell composed of a cylinder of microtubule triplets arranged in a 9+0 pattern. Has a pair of centrioles.
Term
dyneins
Definition
In cilia and flagella, a large motor protein extending from one microtuble doublet to the adjacent doublt. ATP hydrolysis drives changes in dynein shape that lead to bending of cilia and flagella.
Term
basal body
Definition
a euk cell structure consisting of a 9+0 arrangement of microtubule triplets. may organize the assembly of cilium or flagellum.
Term
actin
Definition
a globular protein that links into chains, two of which twist helically about each other, forming microfilaments in muscle and other kinds of cells.
Term
microfilaments
Definition
A cable composed of actin proteins in the cytoplasm of almost every euk cell, making up part of the cytoskeleton and acting alone or with myosin to cause cell contraction.
Term
myosin
Definition
A type of motor protein that ssociates into filaments that interact with actin filaments to cause cell contraction.
Term
pseudopodia
Definition
A cellular extension of amoeboid cells used in moving and feeding.
Term
intermediate filaments
Definition
A componento of the cytoskeleton that includes filaments intermediate in size between microtubules and microfilaments.
Term
primary cell wall
Definition
in plants, a relatively thin and flexible layer that surrounds the plasma membrane of a young cell.
Term
middle lamella
Definition
in plants, a thin layer of adhesive extracellular material, primarily pectincs, found between the primary walls of adjacent young cells.
Term
secondary cell wall
Definition
in plant cells, a strong and durable matrix that is often deposisted in several laminated layers around the plasma membrane and provides protection and support
Term
extracellular matrix (ECM)
Definition
The meshwork surrounding animal cells, consisting of glyco-proteins, polysaccharides, and proteoglycans synthesized and secreted by the cells.
Term
collagen
Definition
A glycoproteinb in the extracellular matrix of animal cells that forms strong fibers, found extensively in connective tissue and bone, the most abundant protein the in animal kingdom.
Term
proteoglycans
Definition
a large molecule consisting of a small core protein with many carbohydrate chains attatched, found in the extracellular matrix of animal cells.
Term
fibronectin
Definition
An extracellular glycoprotein secreted by animal cells that helps them attach to the extracellular matrix.
Term
integrin
Definition
in animal cells, a transmembrane receptor protein with two subunits that interconnects the extracellular matrix and the cytoskeleton.
Term
plasmodesmata
Definition
An open channel through the cell wall that connects the cytoplasm of adjacent plant cells, allowing water, small solutes, and some larger molecules to pass between the cells.
Term
fluid mosaic model
Definition
The currently accepted model of cell membrane structure which envisions the membrane as a mosaic of protein molecules drifting laterally in a fluid bilayer of phospholipids.
Term
aquaporins
Definition
A channel protein in the plasma membrane of a plant, animal, or microorganism cell that specifically facilitates osmosis, the diffusion of free water across the membrane.
Term
diffusion
Definition
The spontaneous movement of a substance down its concentration or electrochemical gradient, from a region where it is more concentrated to a region where it is less concentrated.
Term
concentration gradient
Definition
A region along which the density of a chemical substance increases or decreases.
Term
osmosis
Definition
The diffusion of free water across a selectively permeable membrane.
Term
tonicity
Definition
quality or condition
Term
isotonic
Definition
a solution that when surrounding a cell causes no net movement of water into or out of the cell.
Term
hypertonic
Definition
Referring to a solution that, when surrounding a cell, will cause the cell to lose water.
Term
hypotonic
Definition
Referring to a solution that, when surrounding a cell, will cause the cell to take up water.
Term
osmoregulation
Definition
Regulation of solute concentrations and water balance by a cell or organism.
Term
facilitated diffusion
Definition
The passage of molecules or ions down their electrochemical gradient across a biological membrane with the assistance of specific transmembrane transport proteins, requiring no energy expenditure.
Term
ion channel
Definition
a transmembrane protein channel that allows a specific ion to diffuse across the membrane down its concentration or electrochemical gradient.
Term
gated channels
Definition
A transmembrane protein channel that opens or closes in response to a particular stimulus.
Term
active transport
Definition
The movement of a substance across a cell membrane against its concentration or electrochemical gradient, mediated by specific transport proteins and requiring an expenditure of energy.
Term
sodium-potassium pump
Definition
A transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell.
Supporting users have an ad free experience!