Chapter 3 part 2 test
How is activation energy related to bond energy?
Activation Energy is the additional energy that the reactant molecules need to acquire to cross the energy barrier for them to convert into the products. The energy required to break the bonds is called bond energy.
metabolism
All of the chemical reactions that occur within an organism
Explain how the structure of an enzyme affect its function.
Almost all enzymes are proteins. These enzymes, like other proteins, are long chains of amino acids. Each enzyme also depends on its structure to function properly. Conditions such as temperature and pH can affect the shape and function, or activity, of an enzyme.
carbonic acids (H2CO3)
carbon dioxide reacts with water in blood to form a compound.
Balance a chemical equation.
chemical equation with the same number of atoms of each element on both sides of the equation
What causes bonds in oxygen and glucose molecules to break? And what happens when new bonds form in carbon dioxide and water?
chemical reaction. As energy is added the bonds break and when energy is released the bonds form.
endothermic reaction
energy absorbed. The products in an endothermic reaction have a higher bond energy than the reactants and the difference in bond energy is absorbed from the surroundings.
exothermic reaction
energy released. The products in an exothermic reaction have a lower bond energy than the reactants, and the difference in bond energy is released to the surroundings.
how does the structure of enzyme affects function
if structure changes, substrates will not be able to bind to an enzyme's active sites.
activation energy
is the amount of energy that needs to be absorbed for a chemical reaction to start. when enough activation energy is added to reactants bonds in the reactants break and reaction begins.
lock and key model in enzymes
only certain substrates bind to an enzymes active sites when bound to the enzyme the chemical reaction can occur.
important factors in enzyme structure
order of amino acids and hydrogen bonding between two amino acids
chemical reactions
process by which substances change into different substances through the breaking and forming of chemical bonds.
cellular respiration
process which makes the carbon dioxide and water vapor that you breathe out
catalyst
substance that decreases activation energy and increases reaction rate in a chemical reaction
how do enzymes weaken the bonds in substrates?
the enzyme's shape changes slightly which strains the bonds inside the substrates. The strain on the bonds weaken them.
products
the substances that are formed by the chemical reaction
Explain why concentration is important in a chemical reaction.
Higher the concentration higher the rate of reaction. lower the concentration lower the rate of reaction.
Describe two functions of catalysts in chemical reactions.
- decrease activation energy to start chemical reaction. So the chemical reaction occurs faster. - To increase the rate of chemical reaction
denature
A change in the shape of a protein (such as an enzyme) that can be caused by changes in temperature or pH (among other things).
inducible fit model
A proposed mechanism of interaction between an enzyme and a substrate. It postulates that exposure of an enzyme to a substrate causes the active site of the enzyme to change shape in order to allow the enzyme and substrate to bind (see enzyme-substrate complex).
Explain the effect of a catalyst on activation energy.
Catalyst decreases the activation energy that is needed to start a chemical reaction.
Describe how enzymes catalyze chemical reactions.
Catalysts lower the activation energy for reactions. The lower the activation energy for a reaction, the faster the rate. Thus enzymes speed up reactions by lowering activation energy.
Explain why chemical reactions release or absorb energy.
Endotermic- high energy then reatcants. exothermic- Less energy then reactants
Describe how bonds break and reform during chemical reactions.
Energy is added to break the bonds Energy is released when bonds form.
lock and key model
Enzymes are specific. The only work on the substrate that they "fit." Just like a lock has a specific key to open it. The model of the enzyme that shows the substrate fitting perfectly into the active site.
active site
Substrates temporarily bind to enzymes at specific places
lock-and-key model
The model of the enzyme that shows the substrate fitting perfectly into the active site
Examine a graph of a chemical reaction and determine if the reaction is exothermic/endothermic. Justify your reasoning.
Under normal conditions, the reaction requires a certain amount of activation energy, and it occurs at a certain rate.
enzymes
a molecule; either protein or RNA that acts as a catalyst in biochemical reactions. Change the amount of time needed for equilibrium to be reached
substrates
a part, substance, or element that lies beneath and supports another part substances or element the reactant in reactions catalyzed by enzymes
substrate
a part, substance, or element that lies beneath and supports another part, substance, or element; the reactant in reactions catalyzed by enzymes
chemical equilibrium
a state that exists when the concentration of a substance is the same throughout a space
reactants
a substance or molecule that participates in a chemical reaction
Summarize how temperature and pH effect enzyme function.
affect the shape and function, or activity, of an enzyme.
bond energy
amount of energy needed to break a bond between two particular atoms; or the amount of energy released when a bond forms between two particular atoms.
why enzymes are necessary
because reaction in organisms have to occur at a low body temperature with low concentrations of reactants and at a high rate
optimum
best; most favorable; ideal
Summarize the current model of enzyme function (induced fit model).
theory asserts that when the active site on the enzymes makes contact with the proper substrate, the enzyme molds itself to the shape of the molecule.
