Energy, Enzymes, and Metabolism

What type of enzyme connects monomers together to form a polymer?

Polymerase

What type of enzyme attaches a phosphate group to its substrate?

a kinase

What type of enzyme removes a phosphate group from its substrate?

a phosphatase

What type of enzyme catalyzes an oxidation-reduction reaction?

an oxido-reductase

What type of enzyme catalyzes the hydrolysis of ATP?

an ATPase

What type of enzyme catalyzes a hydrolysis reaction?

a hydrolase

What type of enzyme breaks down nucleic acids?

a nuclease

What type of enzyme breaks down proteins?

a protease

Write out the basic steps of an enzyme catalyzed reaction.

E + S --> ES --> EP --> E + P

What term describes the maximal velocity of a reaction at saturating substrate concentrations?

Vmax

What do we call the concentration of substrate at half Vmax?

the Km

What type of inhibitor binds to an enzyme's active site to inhibit the enzyme?

A competitive inhibitor.

What type of inhibitor binds to a site on the enzyme that is not the active site to inhibit the enzyme?

A Noncompetitive inhibitor.

What two environmental factors can affect enzyme activity?

Temperature and pH

What effect can a change in temperature or pH have on an enzyme that would stop it from functioning?

They could denature the enzyme.

Is the following statement true or false: All enzymes have an optimum temperature range and an optimum pH range.

True

Is the following statement true or false: An enzyme's optimum temperature range and optimum pH range will be the temperature and pH of the environment the enzyme is normally found.

True

What form of enzyme regulation involves a molecule binding to the enzyme at a site that is not the active site to affect the function of the enzyme?

Allosteric regulation

Is allosteric regulation always inhibitory?

No, allosteric regulation can also lead to the activation of an enzyme.

Is allosteric regulation reversible?

Yes

What enzymes are involved in regulating another enzyme's activity through the addition and removal of phosphate groups?

Kinases and phosphatases. Kinases add phosphate groups and phosphatases remove phosphate groups.

If an enzyme is activated by the addition of a phosphate group, then what type of enzyme would activate it?

A kinase.

If an enzyme is activated by the removal of a phosphate group, what type of enzyme would activate it?

A phosphatase.

If an enzyme is activated by the addition of a phosphate group, then what type of enzyme will turn the enzyme off (deactivate it)?

A phosphatase.

If an enzyme is activated by the removal of a phosphate group, then what type of enzyme would turn it off (deactivate it)?

A kinase.

What type of regulation involves the breaking of covalent bonds to turn the enzyme on?

Proteolytic activation.

What type of metabolic pathway breaks molecules down?

Catabolic pathway

What type of metabolic pathway synthesizes molecules?

Anabolic pathway

What type of metabolic pathway tends to release energy?

A catabolic pathway.

What type of energy tends to require the input of energy?

An anabolic pathway.

What is it called when a product of a pathway goes back and inhibits an enzyme that acts earlier in the pathway?

Feedback inhibition

Why is feedback inhibition important?

It prevents over accumulation of the product.

What type of energy is the energy associated with movement?

Kinetic Energy

What type of energy is stored energy that is available to do work?

Potential Energy

List 3 types of kinetic energy in biology.

Heat

Light

Mechanical

List 3 types of potential energy imoportant in biology.

Any 3 of these is fine:

Chemical Energy

Concentration Gradient

Electrical Gradient (Membrane Potential)

Electrochemical Gradient

What type of potential energy is the one that is contained within the covalent bonds of molecules?

chemical Energy

What term refers to a separation of charge across a membrane?

membrane potential

What is it called when there is a difference in the concentration of a substance between two areas?

a concentration gradient

What is the First Law of Thermodynamics?

Energy cannot be created or destroyed

What is the Second Law of Thermodynamics?

Transfer or transformation of energy from one form to another increases the entropy or degree of disorder of a system

What type of reaction has a change in free energy that is less than zero?

An exergonic reaction.

What type of reaction has a change in free energy that is greater than zero?

An endergonic reaction.

What type of reaction releases energy?

An exergonic reaction.

What type of reaction requires the input of energy?

An endergonic reaction.

What type of reaction occurs spontaneously?

An exergonic reaction.

What type of reaction does not occur spontaneously?

An endergonic reaction.

In what type of reaction do the reactants have more free energy than the products?

An exergonic reaction.

In what type of reaction do the reactants have less free energy than the products?

An endergonic reaction.

What is it called when two reactions are linked and the energy released from one reaction provides the input of energy required for the other reaction?

A coupled reaction.

What is one way a cell gets an endergonic reaction to occur?

By coupling it to an exergonic reaction in a coupled reaction.

What specific reaction is the exergonic reaction in many coupled reactions?

The hydrolysis of ATP (ATP ---> ADP + Pi)

List 3 things the hyrdolysis of ATP is used for in a cell.

1. to provide the energy for endergonic reactions

2. to provide the energy for movement

3. to provide the energy for the transportation of substances against their concentration gradient

Is the following reaction exergonic or endergonic:

ADP + Pi ----> ATP

This reaction is endergonic. It requires the input of energy.

What is the name for a reaction in which there is a transfer of electrons?

An oxidation-reduction reaction

(Redox Reaction)

What is oxidation?

Oxidation is the loss of electrons.

What is reduction?

Reduction in the gain of electrons.

If a substance gains electrons, then you would say it has been ________________________.

Reduced

If a substance loses electrons, then you would say it has been _______________________.

Oxidized

What term collectivley describes the series of components that pass electrons to each other in a specific order?

An electron transport chain

How do enzymes increase the rate of a reaction?

By lowering the activation energy.

Are enzymes changed by the reaction that they catalyze?

No

What is the name of the region on an enzyme where the substrate binds?

The active site.

What is the name given to a reactant that the enzyme acts on?

The substrate.

Does an enzyme alter the change in free energy of a reaction?

No