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Exam 2
N/A
131
Biology
Undergraduate 1
10/02/2012

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Term
Cytosol
Definition
semifluid, jelly like substance in which subcellualer components are suspended- in all cells
Term
nucleoid
Definition
DNA is concentrates in a region that is not membran enclosed- prokaryotic cells
Term
plasma membrane
Definition
the membrane at the boundry of every cel that acts as a selective barrier, regulatingthe cells chemical compoasition
Term
nucleus
Definition
contains most of the genes in the eukaryotic cell
Term
nuclear lamina
Definition
a netlike array of protien filaments that maitains the shape of the nucleus by mechanically supporting the nuclear envelop
Term
chromatin
Definition
the cmplex of DNA and protiens maing up chromosomes
Term
nucleoles
Definition
a prominent structure within the nondividing nucleus
Term
ribosomes
Definition
complexes made up of ribosomal RNA and protein, are the cellular components that carry out protein synthesis
Term
vesiles
Definition
a membranous sac in the cytoplasm of a eukaryotic cell
Term
endoplasmic reticulum
Definition
an extensive membranous network in eukaryotic cells, continous with the outer nuclear membrane and composd of ribosome-studded (rough) and ribosome free (smooth) regions
Term
Smooth ER
Definition
outer surface lacks ribosomes
Term
Rough ER
Definition
studded wih ribosomes on the outer surface
Term
golgi apparatus
Definition
an organelle in eukaryotic cells consisting of stacks of flat membranoussacs that modify, store, and route products of the ER and synthesis some products, notable noncellulous carbohydrates
Term
lysosomes
Definition
a membranous sac of hydrolytic enzyme that an animal cell uses to digest(hydrolyzed) macromolecules
Term
Vacuoles
Definition
large vesicles derived from the endoplasmic reticulum and golgi apparatus, intergral parts of cells endomembrane system
Term
Mitochondria
Definition
the sites of cellular respiration, the metobolic process that uses oxygen to generate ATP by extracting energy from sugars, fats, and other fuels
Term
Chloroplasts
Definition
found in plants and algae, sites of photosynthesis
Term
endosymbiont theory
Definition
states that and early ancestor of eukaryotic cells engulfed an oxygen using nonphotosynthetic prokayotic cell. Eventually the engulfed cell formed a relationship with the host cell becoming a endosymbiont
Term
cristae
Definition
an infolding of the inner membran of a mitrochondria
Term
cytoskeleton
Definition
a network of fibers extending throughout the cytoplasm, plays a major role in organizing the structure and activity of the cell
Term
motor proteins
Definition
a protein that interacts with cytoskeletal elements and other cell componenets, producing movement of whole or parts of the cell
Term
microtubule
Definition
a hollow rod composed of tubulin proteins that make up part of the cytoskeleton in all eukaryotic cells and found in cillia and flagella
Term
centrosome
Definition
in animal cells, microtubuls frow from here
Term
centrioles
Definition
within the centrosome is a pir, each composed of 9 sets of triplet microtubules arranged in a ring
Term
flagella
Definition
a cellular appendage specialized for locamotion
Term
cilia
Definition
a short appendage contians microtubules in eukaryotic cells
Term
microfilaments
Definition
solid rods about 7 nm in diameter (also called actin filaments)
Term
actin
Definition
a globular protein
Term
pseudopodia
Definition
a cellular extension of ameoboid cells used in moving and feeding
Term
intermediate filaments
Definition
a component of the cytoskeleton that includes filaments intermediate in size betwwen microtubles and microfilaments
Term
cell wall
Definition
an extracellular structure of plant cells that distinguishes them from animal cells
Term
extracellular matrix
Definition
the meshwork surrounding animal cells, consisting of glycoproteins, polysaccharides, and proteoglycans synthesized and secreted by the cell
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
Integral proteins
Definition
a transmembrane prtein with hydrophobic regions that extend into and often completely span the hydrophobic interior of the membrane and with the aqueous solution on one or both sides of the membrane (lining the channel in the cse of a channel protein)
Term
Peripheral protein
Definition
a protein loosely bound to the surface of a membrane or to part of an intergral poton and not embedded in the lipid bilayer
Term
transport proteins
Definition
a transmembrane protein that helps a certain substance or class of closely reated substances to cross the membrana
Term
diffusion
Definition
the spontaneous movement of a substance down its concentration gradient: more to less concentration
Term
passive transport
Definition
the diffusion of a substance across a biological membrane without the expendture of energy (ATP)
Term
osmosis
Definition
the movement of water across cell membranes and the balance of water between the cell and its enviroment are crucial to organsims
Term
tonicity
Definition
the ability of a surrounding solution to cause a cell to gain or lose water
Term
isotonic
Definition
a solution surrounding a cell, causes no net movement in or out of the cell
Term
hypertonic
Definition
a solution surrounding a cell that makes that causes the cell to lose water
Term
hypotonic
Definition
a solution surrounding a cell that makes that causes the cell to gain water
Term
turgid
Definition
swollen or distended, as in plant cells
Term
flaccid
Definition
lacking turgor (stiffness/firmness)
Term
plasmolysis
Definition
a phenomenon in walled cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall; occurs when the cell loses water to a hypotonic enviroment
Term
facilitated diffusion
Definition
the passage of molecules ions down their electrochemical gradient across a biological membrance with the assisstance of specific transmembrane transpost proteins, requiring no energy expenditure
Term
ion channels
Definition
a transmembrane protein channel that allows a specific ion to diffuse across the membrane dwon its concentration/electrochemical gradient
Term
gated channels
Definition
a transmembrane protein for a specific ion. The opening/closing of such channels may alter a cells membrane potential
Term
active transport
Definition
movement of a substance across the membrane against its concentration/electrochemical gradient, mediated by specific transport protien ad requires ATP
Term
Sodium- Potassium Pump
Definition
a transpot protein in the plasma membrane of animal cells that actively transports 3 sodium out of the cell and 2 potassium into the cell
Term
cotransport
Definition
the coupling of the "downhill" difusion ofone substance to the "uphill" transpot of another aganist its own concentration gradient
Term
exocytosis
Definition
the cellular secretion of bilogical molecules by the fusion of vesicles containting them with the plasma membran
Term
endocytosis
Definition
cellular uptake of biological molecules and particulate matter viz formation of vesicls from the plasma membrane
Term
metabolism
Definition
totality of an organisms chemical reactions
Term
anabolic pathway
Definition
a metabolic pathway that consumes energy to build a molecule
Term
catobolic pathway
Definition
a metabolic pathway that releases energy to breakdown a molecule into simplier molecules
Term
kinetic eergy
Definition
energy associated with relative motion of the object
Term
potential energy
Definition
energy the matter possesses because of its location or structure
Term
thermodynamics
Definition
study ofthe energy transformations that occur in a collection of matter
Term
entropy
Definition
ameasure of disorder, randomness
Term
energy coupling
Definition
use of an exergonic process to drice an endergonicone
Term
ATP
Definition
an adenin-containing nucleoside triphosphat that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells
Term
phosphorylate intermediate
Definition
a molecule (often a reactant) with a phosphate group covalently bound to it, making it more reactive than the unphosphorylated molecule
Term
fermentation
Definition
catabolic process, a partial degradation of sugars or other organic fuel that occurs without the use of oxygen
Term
aerobic respiration
Definition
catabolic pathway (most prevent and efficient), oxygen is consumed as a reactant along with the organic fuel
Term
cellulr respiration
Definition
catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules and use a electron transpot chanin for the production of ATP
Term
redox reactions
Definition
a chemical reaction involving the complete or partial transfer of one or more eletrons from one reactant to another
Term
oxidation
Definition
the loss of electrons from one substance
Term
reduction
Definition
the addition of electrons to another substance
Term
reducing agent
Definition
electron donor in a redox reaction
Term
oxidizing agent
Definition
electron acceptr in a redox reaction
Term
electron transport chain
Definition
sequence of electron carrier molecules (membrane proteins) that shuttle eletrons down a serios of redox reactions and release energy used to make ATP
Term
glycolysis
Definition
a series of reactions that ultimatley splits glucos into pyruvate. Occurs in almost all living cells, serves as the starting point gor fermentation or cellular respiration
Term
cell division
Definition
continuity of life based on reproduction of cells
Term
cell cycle
Definition
the life of a cell from the time it is first frmed from a dividing parent cell until its own division into two daughter cells
Term
chromosome
Definition
cellular structure carrying genetic material in the nucleus, consists of long DNA molecule and associated proteins
Term
chromatin
Definition
te complex of DNA and proteins that mak up chromosomes
Term
somatic cell
Definition
any cell in a multicellulr organism except a sperm or egg or their precursors
Term
gametes
Definition
reproductive cell, sperm or egg
Term
sister chromatide
Definition
each guplicated chromosome has 2, they are joined copies of the orignal chromosome
Term
centrosome
Definition
a region containing specific DNA sequences where the chromatid is attached most closely to sister chromatid
Term
cytokinesis
Definition
the division of the cytoplasm
Term
mitotic phase (M)
Definition
phase of cell cycle- mitosis and cytokinesis, usually shortest phase
Term
interphase
Definition
the perod in the cell cycle (90% of the time) when the cell is not dividing, During interphse, cellular metabolic activity is high, chromosomes and organelles are dyplicated, and cell sixe may increase, usually divided in to G1 phase, S phase, and G2 phase
Term
G1 phase
Definition
the first gap, or growth phase, of the cell cycle, consisting of the portion of interphase befoe DNA syntesis begins
Term
G2 phase
Definition
the second gap, or growth phase, of the cell cycle,consisting of the portion of interphase after DNA synthesis occurs
Term
S phase
Definition
the synthsis phase of the cell cycle; the portion of interphase during which CNA is replicated
Term
Prophase
Definition
1st stage of mitosis, chromatin condense into discrete chromosomesvisible with a light microscope, miotic spindles begins to form, and nucleolus disappears but nuclear envelop remains
Term
Prometaphase
Definition
2nd stage of mitosis, nuclear envelop fragmnts and the spindle microtubules attach to the kinetochores of the chromosomes
Term
Metaphase
Definition
3rd stae of mitosis, spindle is complete and the chromosomes attached to microtubules at their kinetochores are all alligned at the metaphase plate
Term
Anaphase
Definition
4th stage of mitosis, chromatids of each chromosome have spereated a the daugther cromosomes are moving to the poles of the cell
Term
Telophase
Definition
5th stage of mitosis, daughter nuclei are forming and cytokinesis has typically begun
Term
mitotic spindle
Definition
an assemblage of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis
Term
centrosome
Definition
in animal cells- assembly of spindle microtubles starts at the centrosome, subcellular region containing material that functions throughout the cell cycle to organize the cell's microtubules
Term
aster
Definition
a radial array of short microtubles, extends from each centrosome
Term
kinetocore
Definition
a structure of proteins associated with specific sections of chromosomal DNA of each centromere
Term
Meataphase Plate
Definition
an imaginry structure locted at a plane midway between 2 poles of a cell in metaphase
Term
cleavage
Definition
1) the process of cytokinesis in animal cells, characterized by pinching of the plasma membrane.
2) the succession of rapid cell divisions with out significant growth during early embryonic development that converst the zygote to a ball of cells
Term
cleavage furrow
Definition
1st ign of cleavage in an animal cell, a shallow groove around the cell in the cell surface ner the old metaphase plate
Term
cell plate
Definition
a membrane bounded, flattened sac located at the midline of a dividing plant cell, inside which the new cell wall forms during cytokiesis
Term
binary fission
Definition
a method of asexual reproduction by divison in half. In prokaryotes, binar fission des not involve mitosis but in singel celled eukaryotes that undergo binary fission, mitosis is part of the process
Term
origin of replication
Definition
site where the replication of DNA molecule begins, consisting of a specific sequence of nucleotides
Term
cell cycle control system
Definition
a cyclically operating set of molecules in the ekaryotic cell that both triggers and coordinated key events in the cell cycle
Term
check point
Definition
acontrol point in the cell cycle where stop and go ahead signals cn regualte the cycle
Term
G0 phase
Definition
a nondividing state occupied by cells that have left the cell cycle, sometimes reversibly
Term
cyclin
Definition
a cellular protein that occurs in a cyclically fluctuation concentration and that plays an important role in regulation the cell cycle
Term
cyclin-dependent kinase (CdK)
Definition
a proten kinase that is active only when attached to a particular cyclin
Term
growth factor
Definition
1) a protein that must be present in the extracellular enviroment for the growth and normal development of certain types of cells
2) a local regulator that acts on nearby cells to stimulate cell proliferation and differentiation
Term
density-dependent inhibtion
Definition
the phenomenon observed in normal animalcells that causes them to stop diciding when they come into contact with one another
Term
anchorage dependence
Definition
the requirement that a cell mustbe attached to a substratum in order to initiate cell divsion
Term
transforation
Definition
the conversion of a normal animal cell to a cancerous cell
Term
Endosymbiotic
Definition
An endosymbiont is any organism that lives within the body or cells of another organism, i.e. forming an endosymbiosis
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 in mammals, mainly macrophages, neutrophils, and dendritic cells
Term
Pinocytosis
Definition
A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes
Term
Receptor Mediated Endocytosis
Definition
The movement of specific molecules into a cell by the inward budding of vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances
Term
Tight junction
Definition
A type of intercellular junction between animal cells that prevents the leakage of material through the space between cells
Term
Exergonic Reaction
Definition
a spontaneous chemical reaction, in whcih there is a net realease of free energy
Term
Endergonic Reaction
Definition
a non-spontaneous chemical reaction, in which free energy is absorded from the surroundings
Term
Desmosome
Definition
a type of intercellular junction in animal cells that functions as a rivet, fastening cells together
Term
Gap Junction
Definition
a type of intercellular junction in animal cells, consisting of proteins surrounding a pore that allows the passage of materials between cells
Term
Phospholipid
Definition
a lipid made up of glycerol joined to two fatty acids and a phosphate group. The hydrocarbon chains of the fatty acids act as nonpolar, hydrophobic tails, while the rest of the moelcule acts as a polar, hydrophilic head, Phospholipids form bilayers that function as bilogical membranes
Term
Hydrophilic
Definition
having an affinity to water
Term
Hydrophobic
Definition
having no affinity to water
Term
Pyruvate Oxidation
Definition
The process in cellular metabolism where pyruvate is turned into acetyl-coA
Term
Citric Acid Cycle
Definition
A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA(derived from pyrucate) to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokayotes; together with pyruvate oxidation, the second major stage in cellular respiration
Term
Oxidative Phosphorylation
Definition
The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration
Term
Alcohol Fermentation
Definition
glycolysis followed by the reduction of pryuvate to ethly alcohol, regenerating NAD+ and releasing carbon dioxide
Term
Lactic Acid Fermentation
Definition
glycolysis followed by the reduction of pyruvate to lactate, regeneration NAD+ with no release of carbon dioxide
Term
Obligate Anaerobes
Definition
an organism that only carries out fermentation or anaerobi respiration, Such organisms cannot use oxygen and in fact may be poisoned by it
Term
Facultative Anaerobes
Definition
an organism that makes ATP by aerobic repiration if oxygen is present but that switches to anaerobic respiration or fermentation if oxygen is not present
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