Energy, Enzymes, and Biological Reactions

The diagram represents the energy levels that are involved in a biochemical reaction in which molecules a and b combine to form ab. Which statement about the effects of the enzyme on this reaction is correct?

• The enzyme will increase the activation energy and the overall energy of the reaction

• The enzyme will decrease the activation energy but not the overall energy of the reaction.

• The enzyme will increase the activation energy but not the overall energy of the reaction

• The enzyme will not affect the activation energy or the energy of the reaction

• Without enzyme, there will be no reaction.

Tags

NGSS.HS-PS1-5

Which statement about enzymes is not correct?

• Enzymes speed up the rate of chemical reactions

• Enzymes are not consumed during chemical reactions

• Enzymes lower the activation energy needed for chemical reactions

• Enzymes increase the energy of chemical reactions

• Enzymes are substrate specific

Tags

NGSS.HS-LS1-7

_______ is an example of an endothermic chemical reaction

• photosynthesis

• cellular respiration

• breakdown of ATP molecule

• oxidation

• combustion

Tags

NGSS.HS-LS1-5

The tendency of disorder to decrease in a system is defined as

• entropy

• enthalpy

• endergonic

• free energy

• equilibrium

_______ must be provided to ensure the start of a chemical reaction.

• entropy

• free energy

• thermodynamics

• activation energy

• equilibrium

What is the name of the substance that an enzyme catalyzes?

• inhibitor

• substrate

• active site

• allosteric site

• catalyst

Choose the best explanation for the shape of the following graph

• The enzyme is saturated with substrate

• There is a competitive inhibitor present

• There is a non-competitive inhibitor present

• The maximum amount of product has been formed

• All the reactant has been used

Which factor affects the rate of an enzymatic reaction?

• pH

• Temp

• concentration of substrate

• nature of the substrate

• All of the above

Unlike many other chemical reactions, enzymes are very specific in the reaction they catalyze. The source of the specificity lies in

• the magnitude of entropy in the reaction

• the stability of the enzyme substrate complex

• the structure of the active site

• the concentration of substrate that is available

• the concentration of enzyme that is available

Consider the process of allosteric regulation, which statement best describes the effect of an activator on an enzyme.

• inhibition of substrate binding

• increase in the number of substrates that can simultaneously bind to one enzyme

• increases the rate of inhibitor binding

• increase the rate of reaction

• decreases the enzymes ability to functions