LO7 Flashcards
Definition: energy
the capacity to do work
energy is used when work is performed
kinetic energy
sodium potassium pump is an example of
kinetic energy
capacity to do work
potential energy
concentration gradients are an exmaple of
potential energy
energy cannot be created or destroyed only converted from one form to another
first law of thermodynamics
capture energy from their environment and convert it to a usable form
open systems
organisms are _____ systems
open
photosynthesis is an example of an _______ system
open
living organisms are highly ordered which also means they have a low ______
entropy
as energy conversions occur in living organisms, energy is ____ in the form of heat
lost
entropy is continuously increasing
second law of thermodynamics
definition: entropy
disorder/randomness
sum of all chemical reactants
metabolism
G
free energy
definition: free energy
the amount of energy available to do cellular work
exergonic reactions are those that ______ free energy
release
in exergonic reactions products have ______ free energy than the reactants
less
exergonic reactions have a ________ value
negative change in free energy
definition: catabolic reaction
break down larger molecules into smaller ones through hydrolysis reactions
catabolic reactions are typically ______ reactions
exergonic
______ reactions require free energy
endergonic reactions
have a +free energy value
endergonic reactions
in endergonic products have ______ free energy than the reactants
more
synthesize larger molecules from smaller ones through condensations reactions
anabolic reactants
anabolic reactions are typically ______ reactions
endergonic
endergonic reactions can be powered by _____
ATP
ATP provides energy to other molecules by ________________ to another molecule
transferring the 3rd phosphate group
endergonic reactions can be powered by ___________
electrons
energy of electrons is transferred from one molecule to another
redox reactions
NAHD is the _____ form
reduced
NAD+ is the ________ form
oxidized
electron acceptor molecules become _____ when they accept electrons
reduced
enzymes are ________________
biological catalysts
definition: catalysts
speed up chemical reactions
biological catalysts include
protein enzymes and RNA molecules(ribosomes)
enzymes are ________ specific
highly
definition: where the specific reactant molecule binds to an enzyme
active site
enzymes only catalyze _______ reactions
exergonic
enzymes work by __________ the activation energy
lowering
definition: activation energy
energy required to break the bonds of the reactant molecules
How do enzymes reduce the activation energy?
by bringing the reactant molecules close together and putting strain on their bonds
definition: substrates
reactant molecules
enzyme-catalyzed reaction steps
- substrate molecules binds to an enzyme’s active site
- unstable enzyme-substrate complex is formed
- substrate is converted into one or more products
- enzyme is recycle and can catalyze that reaction again
definition: induced fit
when the enzyme and substrate bind
hydrolysis reactions are _______ reactions
exergonic
as temperature increases, catalytic activity _______ until an enzyme denatures
increases
defintion: denaturation
enzyme unfolds and becomes nonfunctional
where structures are broken when an enzyme denatures?
2°, 3°, and 4° structure
many enzymes require ________ to function
cofactors
most trace elements function as ________ by binding to and activating specific enzymes
cofactors
definition: products of one enzymatic reaction controls the activity of another enzyme in the pathway
feedback inhibition
definition: a molecule binds to an enzyme at a site other than its active site
allosteric regulation
definition: makes substrate binding possible
activation
definition: preventing substate binding
deactivation
definition: molecule temporarily. binds to an enzyme’s active site and competes with sites normal substrate
competitive inhibition
definition: permanently binds to an enzyme at its active site or elsewhere making the enzyme nonfunctional
irreversible inhibition
Law: living organisms can exchange energy with their environment
first law of thermodynamics
disorder is increasing
second law of thermodynamics
condensation reactions are ________ reactions
endergonic
components of an ATP molecule are
adenine, a nitrogenous base, ribose, purine, a five carbon monosaccharide, phosphate groups
redox reactions in cells usually involve the transfer of a _______ rather than just an electron
hydrogen atom
NADH is the _________ form of NAD+
reduced
NADH has _______________ than NAD+
more energy and electrons
____________ may be RNA molecules
enzymes
activation energy of a reaction begins reaction by using energy to ______________________
break existing chemical bonds of reactants
Steps of an enzyme catalyzed reaction
- substrate molecules bind to enzymes active site
- unstable enzyme substrate complex is formed
- enzyme and substrate undergo shape change known as induced fit
- substrate converted into one or more products
- Products released from enzyme
- enzyme recycled
enzymes typically denature at high or low pH because the _________ of their _______- are altered
ionic bonds; tertiary and quaternary
cAMP regulates a kinase enzyme by
removing an allosteric inhibitor from kinase, thus activating it
