Shared Flashcard Set

Details

biol112 exam 2 vocab
vocab
91
Biology
Undergraduate 1
02/19/2012

Additional Biology Flashcards

 


 

Cards

Term
metabolism
Definition
the biochemical reactions that allow a cell or organism to extract energy from its surroundings and use that energy to maintain itself, grow, and reproduce
Term
kinetic energy
Definition
the energy of motion
Term
potential energy
Definition
stored energy
Term
thermodynamics
Definition
the study of the energy flow during chemical and physical reactions
Term
first law of thermodynamics
Definition
the principle that energy can be transferred and transformed but it cannot be created or destroyed
Term
second law of thermodynamics
Definition
principle that for any process in which a system changes from an initial to a final state, the total disorder of a system and its surroundings always increases
Term
entropy
Definition
disorder, in thermodynamics
Term
spontaneous reactions
Definition
chemical or physical reaction that occurs without inside help
Term
enthalpy
Definition
the potential energy in a system
Term
exothermic
Definition
referring to a reaction that releases energy, that is, a reaction in which the products have less potential energy than the reactants
Term
endothermic
Definition
referring to a reaction that absorbs energy, that is, a reaction in which the products have more potential energy than the reactants
Term
free energy
Definition
the energy in a system that is available to do work
Term
reversible
Definition
the term indicating that a reaction may go from left to right or from right to left, depending on conditions
Term
exergonic reaction
Definition
reaction that has a negative change in free energy because it releases free energy
Term
endergonic reaction
Definition
reaction that can proceed only if free energy is supplied
Term
catabolic pathway
Definition
a metabolic pathway in which energy is released by the breakdown of complex molecules to simpler compounds. an individual reaction in a catabolic pathway is a catabolic reaction.
Term
catabolic reaction
Definition
cellular reaction that breaks down complex molecules such as sugar to make their energy available for cellular work
Term
anabolic pathway
Definition
a metabolic pathway in which energy is used to build complicated molecules from simpler ones; also called a biosynthetic pathway. An individual reaction in a(n) ____________ ___________ is a _____________ reaction, also called a biosynthetic reaction.
Term
anabolic reaction
Definition
metabolic reaction that requires energy to assemble simple substances into more complex molecules
Term
biosynthetic reaction
Definition
an individual reaction in an anabolic pathway (biosynthetic pathway)
Term
energy coupling
Definition
the process in living cells by which the hydrolysis of ATP is coupled to an endergonic reaction so that energy is not wasted as heat
Term
phosphorylation
Definition
the addition of a phosphate group to a molecule
Term
ATP/ADP cycle
Definition
the continual hydrolysis and resynthesis of ATP in living cells
Term
activation energy
Definition
the initial input of energy required to start a reaction
Term
catalyst
Definition
substance with the ability to accelerate a spontaneous reaction without being changed by the reaction
Term
catalysis
Definition
the process of accelerating a chemical reaction with a catalyst
Term
enzymes
Definition
protein that accelerates the rate of a cellular reaction
Term
substrate
Definition
the particular reacting molecule or molecular group that an enzyme catalyzes
Term
enzyme specificity
Definition
the ability of an enzyme to catalyze the reaction of only a single type of molecule or group of closely related molecules
Term
active site
Definition
the region of an enzyme to which substrate(s) bind and where catalysis occurs
Term
cofactor
Definition
an inorganic or organic nonprotein group that is necessary for catalysis to take place
Term
coenzymes
Definition
organic cofactors that include complex chemical groups of various kinds
Term
saturated enzymes
Definition
enzymes for which increases in substrate concentration have no effect on the reaction rate
Term
competitive inhibition
Definition
inhibition of an enzyme reaction by an inhibitor molecule that resembles the normal substrate closely enough so that it fits into the active site of the enzyme
Term
noncompetitive inhibition
Definition
inhibition of an enzyme reaction by an inhibitor molecule that binds to the enzyme at a site other than the active site and, therefore, does not compete directly with the substrate for binding to the active site
Term
allosteric regulation
Definition
specialized control mechanism for enzymes with an allosteric site, a regulatory site outside the active site, that may either slow or accelerate activity depending on the enzyme
Term
allosteric site
Definition
a regulatory site outside the active site
Term
allosteric activator
Definition
molecule that converts an enzyme with an allosteric site, a regulatory site outside the active site, from the active form to the inactive form
Term
allosteric inhibitor
Definition
molecule that converts an enzyme with an allosteric site, a regulatory site outside the active site, from the active form to the inactive form
Term
feedback inhibition / end-product inhibition
Definition
in enzyme reactions, regulation in which the product of a reaction acts as a regulator of the reaction
Term
cellular respiration
Definition
the process by which energy-rich molecules are broken down to produce energy in the form of ATP
Term
aerobic respiration
Definition
the form of cellular respiration found in eukaryotes and many prokaryotes in which oxygen is a reactant in the ATP-producing process
Term
anaerobic respiration
Definition
the form of cellular respiration found in some prokaryotes in which a molecule other than oxygen is used in the ATP-producing process
Term
oxidation
Definition
the removal of electrons from a substance
Term
oxidized
Definition
substance from which the electrons are removed during oxidation
Term
reduction
Definition
the addition of electrons to a substance
Term
reduced
Definition
substance that receives electrons during reduction
Term
redox reactions
Definition
coupled oxidation-reduction reaction in which electrons are removed from a donor molecule and simultaneously added to an acceptor molecule
Term
glycolysis
Definition
stage of cellular respiration in which sugars such as glucose are partially oxidized and broken down into smaller molecules
Term
substrate-level phosphorylation
Definition
an enzyme-catalyzed reaction that transers a phosphate group from a substrate to ADP
Term
pyruvate oxidation (pyruvic acid oxidation)
Definition
stage of cellular respiration in which the three-carbon molecule pyruvate is converted into a two-carbon acetyl group that is completely oxidized to carbon dioxide
Term
citric acid cycle / Krebs cycle / tricarboxylic acid cycle
Definition
series of reactions in which acetyl groups are oxidized completely to carbon dioxide and some ATP molecule are synthesized
Term
oxidative phosphorylation
Definition
synthesis of ATP in whcih ATP synthase uses an H+ gradient built by the electron transfer system as the energy source to make the ATP
Term
electron transfer system
Definition
stage of cellular respiration in which high-energy electrons produced from glycolysis, pyruvate oxidation, and the citric acid cycle are delivered to oxygen by a sequene of electron carriers
Term
ATP synthase
Definition
a membrane-spanning protein complex that couples the energetcally favorable transport of protons across a membrane to the synthesis of ATP
Term
cell fractionation
Definition
technique that divides cells in specific directions in a developing organ
Term
mitochondrial electron transfer system
Definition
series of electron carriers that alternately pick up and release electrons, ultimately transferring them to their final acceptor oxygen
Term
cytochromes
Definition
proteins with a heme prosthetic group that contains an iron atom
Term
proton-motive force
Definition
stored energy that contributes to ATP synthesis, as well as to the cotransport of substances to and from mitochondria
Term
chemiosmotic hypothesis
Definition
model proposing that mitochondrial electron transer produces an H+ gradient and than the gradient powers ATP synthesis by ATP synthase
Term
fermentation
Definition
process in which electrons carried by NADH are transferred to an organic acceptor molecule rather than to the electron transfer system
Term
lactate fermentation
Definition
reaction in which pyruvate is converted into lactate
Term
alcoholic fermentation
Definition
reaction in which pyruvate is converted into ethyl alcohol and CO2 in a two-step series that also converts NADH into NAD+
Term
strict anaerobes
Definition
organism in which fermentation is the only source of ATP
Term
facultative anaerobes
Definition
an organism that can live in the presence or absence of oxygen, using oxygen when it is present and living by fermentation under anaerbobic conditions
Term
strict aerobes
Definition
cell with an absolute requirement for oxygen to survive, unable to live solely by fermentations
Term
photosynthesis
Definition
the converstion of light energy to chemical energy in the form of sugar and other organic molecules
Term
autotrophs
Definition
an organism that produces its own food using CO2 and other simple inorganic compounds from its environment and energy from the sun or from oxidation of inorganic substances
Term
photoautotrophs
Definition
photosynthetic organism that uses light as its energy source and carbon dioxide was its carbon source
Term
heterotrophs
Definition
an organism that acquires energy and nutrients by eating other organisms or their remains
Term
light-dependent reactions
Definition
the first stage of photosynthesis, in which the energy of sunlight is absorbed and converted into chemical energy in the form of ATP and NADPH
Term
light-independent reactions / Calvin Cycle / C3 pathway
Definition
the second stage of photosynthesis, in which electrons are used as a source of energy to convert inorganic CO2 to an organic form
Term
CO2 fixation
Definition
process in which electrons are used as a source of energy to convert inorganic CO2 to an organic form
Term
electromagnetic spectrum
Definition
the range of wavelengths or frequencies of electromagnetic radiation extending from gamma rays to the longest radio waves and including visible light
Term
chlorophylls
Definition
molecules of green pigment that absorb photons of light in photosynthesis
Term
carotenoids
Definition
molecule of yellow-orange pigment by which light is absorbed in photosynthesis
Term
absorption spectrum
Definition
curve representing the amount of light absorbed at each wavelength
Term
action spectrum
Definition
graph produed by plotting the effectiveness of light at each wavelength in driving photosynthesis
Term
photosystems
Definition
a large complex into which the light-absorbing pigments for photosynthesis are organized with proteins and other molecules
Term
photosystem I
Definition
in photosynthesis, a protein complex in the thylakoid membrane that uses energy absorbed from sunlight to synthesize NADPH
Term
photosystem II
Definition
in photosynthesis, a protein complex in the thylakoid membrane that uses energy absorbed from sunlight to synthesize ATP
Term
antenna complex / light-harvesting complex
Definition
in photosystems, the sites at which light is absorbed and converted into chemical energy during photosynthesis, an aggregate of many clorophyll pigments and a number of carotenoid pigments that serves as the primary site of absorbing light energy in the form of photons
Term
reaction center
Definition
part of photosystems I and II in chloroplasts of plants. in the light-dependent reactions of photosynthesis, the reaction center receives light energy absorbed the antenna complex in the same photosystem
Term
noncyclic electron flow
Definition
pathway in photosynthesis in which electrons travel in a one-way direction from H2O to NADP+
Term
photophosphorylation
Definition
the synthesis of ATP coupled to the transfer of electrons energized by photons of light
Term
cyclic electron flow
Definition
an electron transport pathway associated with photosystem I in photosynthesis that produces ATP without the synthesis of NADPH
Term
RuBP carboxylase/oxygensase (rubisco)
Definition
an enzyme that catalyzes the key reaction of the Calvin cycle, carbon fixation, in which CO2 combines with RuBP (ribulose 1,5-biphosphate) to form 3-phosphoglycerate(3PGA)
Term
photorespiration
Definition
a process the metabolizes a by-product of photosynthesis
Term
C4 pathway
Definition
in C4 plants the pathway to fix CO2 into oxaloacetate in mesophyll cells and then produce CO2 for the Calvin cycle in bundle sheath cells
Term
CAM pathway
Definition
in CAM plants, the pathway to fix CO2 into oxaloacetate and then produce CO2 for the Calvin cycle, both occuring in mesophyll cells, but separated by time of day. CAM stands for "crassulacean acid metabolism"
Term
crassulacean acid metabolism
Definition
a biochemical variation of photosynthesis that was discovered in a member of the plant family Crassulceae. Carbon dioxide is taken up and stored during the night to allow the stomata to remain closed during the daytime, decreasing water loss
Supporting users have an ad free experience!