Chapter 6 Review
a specific molecule that is altered in defined steps, resulting in a product. ( always catalyzed by an enzyme )
release energy by breaking down complex molecules to simpler compounds.
consume energy to build complicated molecules from simpler ones.
decrease in energy
increase in entropy
first law of thermodynamics
energy can be transferred and transformed but never created nor destroyed.
second law of thermodynamics
every energy transfer or transformation increases the entropy of the universe.
total heat of a system or internal energy
a systems energy that can preform work when pressure and temperature are constant. measure of systems instability.
a process that leads to an increase in entropy without an input of energy.
loss of free energy, increase of entropy, delta G is negative, temperature is increased, enthalpy is decreased.
absorbs free energy, decrease of entropy, delta G is positive, temperature is decreased, enthalpy is increased.
ribose, 3 nitrogenous bases, adenine, and 3 phosphate groups that is a renewable source.
made by a hydrolysis reaction where terminal phosphate bond is broken and a molecule of inorganic phosphate is left over.
exergonic process to drive an endergonic one. ATP is responsible for this in cells and acts as an intermediate source of energy that powers cellular work.
transfer of a phosphate group from ATP to another molecule and that molecule covalently bonds to a phosphate group.
hydrolysis of sucrose
involves breaking bonds between glucose and fructose and one of the bonds of a water molecule which then forms 2 new bonds
activation energy/ free energy of activation
the energy required to contort the reactant molecules so the bonds can break. pushes reactants to top so they can go “downhill”.
when molecules have absorbed energy for the bonds to break, the reactants are in an unstable condition.
formation of bonds
breaking of bonds
speed up enzyme reactions
the reactant an enzyme acts on
enzyme- substrate complex
an enzyme bonded to a substrate when there are 2 or more substrates.
where enzyme binds to substrate
to speed up reactions…
add more enzyme.
activity of enzyme
effected by pH and temperature
non protein helpers for catalytic activity.
cofactors of enzymes include…
metal atoms: zinc, iron, and copper.
reduce productivity of enzymes by blocking substrates from entering active site.
do not directly compete with substrate but instead bind to another part of the enzyme, changing its shape.
permanent change in genes.
any case in which proteins function at one site is affected by the binding of a regulatory molecule to a separate site. This changes an enzymes shape and function of active site.
stabilizes the shape of a functioning active site.
stabilizes the inactive form of an enzyme.
a substrate molecule binding to one active site in its multi subunit enzyme triggers a shape change in all the subunits. This increases the catalytic activity at the other active sites and amplifies the response of enzymes to substrates.
forward and backward reactions occur at the same rate and delta G equals 0. This preforms NO work and has no net change.
cells maintain this as open systems.