Enzymes lower the activation energy, allowing a larger proportion of random collisions to kick the substrates over the energy barrier.
Reduction occurs if the number of C–H bonds increases, while oxidation occurs if the number of C–H bonds decreases.
Enzymes catalyze the oxidation of organic molecules in small steps, allowing useful energy to be harvested.
Activation energy is the energy required to convert a reactant to a product, even if the product is at a lower overall energy level than the reactant.
It often leads to the formation of an enzyme-substrate complex.
Free energy is the energy available to do work, such as driving chemical reactions.
No, enzymes cannot change the equilibrium point; they accelerate both the forward and backward reactions by the same factor.
About one-fifth of a second.
Chemical reactions proceed spontaneously in the direction that leads to a loss of free energy, which is energetically favorable.
The three kinds of molecular motions are translational motion, vibrations, and rotations.
Enzymes lower the activation energy barriers for chemical reactions, making them more likely to occur.
The chemical energy is dissipated as heat and irretrievably dispersed in the chaotic random thermal motions of molecules.
Reactions proceed spontaneously in the direction that leads to a loss of free energy, meaning they are energetically favorable.
Rapid binding allows enzymes to catalyze reactions efficiently, even though both enzymes and substrates are present in relatively small numbers in a cell.
A substance that can lower the activation energy of a reaction, thereby increasing the rate of chemical reactions.
Raising the temperature increases the number of molecules with sufficient energy to overcome the activation energy nonselectively, speeding up all reactions, unlike enzyme catalysis which is selective.
The rate of encounter depends on the concentration of the substrate molecule.
A reaction can proceed spontaneously if it results in a net increase in the disorder of the universe.
Enzymes bind to substrates and reduce the activation energy of chemical reactions, allowing them to proceed rapidly at normal temperatures.
No, an enzyme cannot change the direction of a reaction.
Enzymes hold substrate molecules in a way that reduces the activation energy, increasing the probability of a reaction.
Because small organic molecules diffuse nearly as rapidly through the cytosol as they do through water.
Because the molecules are in a relatively stable state and require an input of activation energy to change to a lower energy state.
The unique shape of each enzyme contains an active site that allows only particular substrates to bind, ensuring specificity in catalysis.
Some enzymes can speed up reactions by factors of 10^14 or more.
The average net distance is proportional to the square root of the time involved.
Enzyme molecules remain unchanged after participating in a reaction and can function over and over again.
An enzyme can catalyze the reaction of thousands of substrate molecules every second.
Enzymes steer reactions in cells through specific reaction paths by being highly selective and precise, usually catalyzing only one particular reaction.
The active site is a pocket or groove in the enzyme into which only particular substrates will fit, allowing the enzyme to catalyze a specific reaction.
Enzyme-catalyzed reactions reach equilibrium faster but do not change the equilibrium point compared to uncatalyzed reactions.
Diffusion is the process by which molecules explore the space inside the cell by wandering through it, causing them to collide with a huge number of other molecules each second.
Sets of enzymes determine the reaction pathway by selectively lowering the activation energy of only one of the several possible chemical reactions that its bound substrate molecules could undergo.
Catalysts lower the activation energy required for reactions, making it easier for reactants to convert to products.
ΔG is a direct measure of the energy change in a system and determines whether a reaction can occur spontaneously.
Cells couple energetically favorable reactions, which release energy, to energetically unfavorable reactions, which produce biological order.
They form few noncovalent bonds and dissociate rapidly, preventing incorrect associations.
