AP Bio Unit 3 Quiz Flashcards
Metabolism
all of the chemical reactions in an organism
Metabolic pathways
series of chemical reactions that either build complex molecules or break down complex molecules
What are the two types of metabolic pathways?
Catabolic and anabolic
Catabolic pathway
pathways that release energy by breaking down complex molecules into simpler compounds
Anabolic pathways
pathways that consume energy to build complicated molecules from simpler compounds
Energy
the ability to do work
kinetic energy
energy associated with motion
thermal energy
energy associated with movement of atoms or molecules
potential energy
stored energy
chemical energy
potential energy available for release in a chemical reaction
1st Law of Thermodynamics
Energy cannot be created nor destroyed, energy can be transferred and transformed
2nd Law of Thermodynamics
Energy transformation increase the entropy of the universe
Free Energy
Concept used by scientists to determine the likelihood of reactions in organisms, or if the reactions are energetically favorable.
Exergonic Reaction
reactions that release energy, spontaneous, ΔG＜0, cellular respiration
Endergonic Reaction
reactions that absorb energy, reaction is not spontaneous, ΔG＞0, photosynthesis
what 3 kinds of work do cells perform?
mechanical, transport, chemical
What is mechanical work?
movement (i.e. beating cilia, movement
of chromosomes, contraction of muscle cells)
What is transport work?
pumping substances across membranes
against spontaneous movement
What is chemical work?
synthesis of molecules (ie building
polymers from monomers)
Adenosine Triphosphate
molecule that organisms
use as a source of energy to perform work
What does ATP do?
ATP couples exergonic reactions to endergonic reactions to power cellular work. Organisms obtain energy by breaking the bond between the 2nd and 3rd phosphate in a hydrolysis reaction. ATP → ADP
What is phosphorlation?
the released phosphate moves
to another molecule to give energy
Can ATP be regenerated?
ADP can be regenerated to ATP via the ATP
cycle
How does cells increase the rate of metabolic reactions?
enzymes
What are enzymes?
macromolecules that
catalyze (speed up) reactions by
lowering the activation energy
Induced Fit
enzymes will change the shape of their
active site to allow the substrate to bind better
enzyme catabolism vs enzyme anabolism
enzyme catabolism helps break down complex molecules and enzyme anabolism helps build complex molecules
What factors are enzymes effected by?
Temperature, pH, chemicals
Enzyme cofactors
non protein molecules that assist
enzyme function, inorganic cofactors consist of metals, can be bound loosely or tightly
Holoenzyme
enzyme with cofactor attached to it
coenzyme
organic cofactors (ie vitamins)
enzyme inhibitors
reduce the activity of specific
enzymes, inhibition can be permanent or irreversible
permanent inhibitation
inhibitor binds with covalent bonds (ie toxins and poison)
reversible inhabitation
inhibitor binds with weak
interactions
competitive inhibitors
reduce enzyme activity by
blocking substrates from binding to the active site, can be reversed with increased substrate concentrations
allosteric regulation
molecules bind (noncovalent
interactions) to an allosteric site which changes the shape and function of the active site
allosteric activator
substrate binds to allosteric
site and stabilizes the shape of the enzyme so
that the active sites remain open
allosteric inhibitor
substrate binds to allosteric
site and stabilizes the enzyme shape so that the active sites are closed (inactive form)
Cooperativety
substrate binds to one active site
(on an enzyme with more than one active site) which stabilizes the active form
