chapter 3 Flashcards
energy
capacity to do work
potential energy
energy in position or stored
kinetic energy
energy in motion
chemical energy
form of potential energy
energy released from chemical bonds when bond is broken
forms of kinetic energy
electrical, mechanical, sound, radiant, heat
electrical energy
movement of charged particles
mechanical energy
exhibited by objects in motion due to applied force
sound energy
molecule compression caused by vibrating object
radiant energy
energy of electromagnetic waves
heat
kinetic energy from movement of atoms, ions, molecules
thermodynamics
study of energy transformations
1st law of thermodynamics
energy can’t be created or destroyed it can only change in form
2nd law of thermodynamics
energy is transformed; some energy is lost to heat
oxidation-reduction reaction
redox reaction ; electrons moved from one chemical structure to another
oxidation (oxidized)
structure that loses electron
reduction (reduced)
structure that gains an electron
nicotinamide adenine dinucleotide
NAD+
irreversible reaction
net loss of reactants and a net gain of products
reversible reaction
does not proceed only to the right - no net charge in concentration of either reactants or products- equilibrium
reaction rate
measure of how quickly chemical reaction takes place
activation energy
energy required to break existing chemical bonds – reaction rate
enzymes
accelerate chemical reaction (catalyst)
uncatalyzed vs catalyzed
only facilitate reactions that would already occur
increase rate of product formation
specificity
permits only a single substrate to bind
helps catalyze only one specific reaction
cofactors
helper ions/molecules required to ensure that a reaction occurs
dehydrogenases
involved in electron transfer
kinases
transfer phosphate groups
optimal temperature
usually 40C to 104F for human enzymes
optimal ph
between ph of 6 and 8
inhibitors
bind enzymes and turns them off
competitive inhibitor
resembles substrate and binds to active site of enzyme
compete for occupation of active site
noncompetitive inhibitors
do not resemble substrate
allosteric site
bind a site other than active site( allosteric inhibitors)
metabolic pathway
series of enzymes; products of one enzyme becomes substrate of the next
multienzyme complex
group of attached enzymes
work in sequence of reactions
phosphorylation
addition of phosphate group
performed by phosphorylases or kinases
dephosphorylation
removal of phosphate group performed by phosphatases
glucose oxidation
breakdown of glucose with energy release
carbon dioxide and water formed
energy rich molecule
substrate level of phosphorylation
least common energy can be used directly
oxidative phosphorylation
energy used indirectly energy released to coenzymes then transformed to form atp
cytosol
liquid component of cytoplasm
mitochondria
power house of the cell
glycolysis
breakdown of glucose to form pyruvate acid; doesn’t require oxygen
production of 2 atp and 2 nadh
intermediate stage
linked between glycolysis and citric acid cycle
