Chapter 6: How Cell Utilize Energy

Question 1

What is metabolism?

Answer 1

The totality of an organism’s chemical reactions.

Question 2

What is Kinetic Energy?

Answer 2

The energy of motion.
The energy that is actually doing the work.

Question 3

What is Potential Energy?

Answer 3

The energy that matter possesses as a result of its location or structure. (STORES ENERGY)

Question 4

Heat or Thermal Energy

Answer 4

The kinetic energy is associated with the random movement of atoms or molecules.

Question 5

Second Law of Thermodynamics

Answer 5

Energy cannot be changed from one form to another without the loss of usable energy.
Energy conversion increases the disorder of the universe.
Heat is the least usable form of energy.

Question 5

Light Kinetic Energy

Answer 5

The type of kinetic energy that can be harnessed to power photosynthesis.

Question 6

First Law of Thermodynamics

Answer 6

Energy in the universe is constant and energy can be changed from one form to another.
Energy cannot be created or destroyed!

Question 7

Entropy

Answer 7

The measure of disorder, or randomness.

Question 8

Chemical reactions will either…

Answer 8

Store energy or release it.

Question 9

Endergonic Reaction

6 points to remember

Answer 9

Absorbs free energy from its surroundings and it’s not spontaneous.
* Increase in free energy
*High capacity to change
*Stable
*Stores Energy
*Non-spontaneous
*Anabolism

Question 10

Exergonic Reaction

6 points to remember

Answer 10

Net release of free energy.
*Free Energy decreases.
*Low capacity to change
*Unstable
*Releases Energy
*Spontaneous
*Catabolism

Question 11

Free Energy (G)

Answer 11

Amount of energy available to work.

Question 12

Metabolic Pathway

Answer 12

SERIES OF CHEMICAL REACTIONS that either break down complex molecules or builds.

Question 13

Catabolism

Answer 13

Breaks down complex molecules into smaller compounds.
(cellular respiration)

Question 14

Anabolism

Answer 14

Builds a complex compound.

(photosynthesis)

Question 15

What is ATP composed of?

Answer 15

Ribose (a sugar)
Adenine (a nitrogenous base)
Three phosphate groups.

Question 15

Energy Coupling

Answer 15

USES THE ENERGY RELEASED FROM EXERGONIC REACTIONS TO DRIVE ESSENTIAL ENDERGONIC REACTIONS usually the energy in ATP molecules. One feeds into the other.

Question 16

ATP is what kind of biomolecule?

Answer 16

Nucleic Acid.

Question 17

Hydrolysis of ATP

Answer 17

ATP can be hydrolyzed to ADP by the addition of water. When one phosphate group is removed by breaking a bond, it releases energy.

Exergonic Process

Question 18

Enzymes

Answer 18

Speed up the cell’s chemical reactions by lowering the energy barriers.
and also,
Start reactions
Stop reactions
Slow down reactions

Question 19

Activation Energy (EA)

Answer 19

The required energy that is needed for the reaction.

Question 20

If no enzyme is present..

Answer 20

Reactions will take longer to occur.

Question 21

Substrate

Answer 21

Molecules that react with the enzyme.

Question 22

Active Site

Answer 22

The specific design of the enzyme for specific molecules (substrate)

Question 23

Enzyme-Substrate Complex

Answer 23

Enzyme and substrate are combined to create a reaction.

Question 24

What two conditions can affect the activity of the enzymes?

Answer 24

Temperature and pH.

Question 25

What is catalysis?

Answer 25

The reaction created when a substrate and an enzyme bind.

Question 26

Cofactors

Answer 26

Nonprotein helpers.
Bind to the active site
Function in catalysis.
Involved in chemical process.
Inorganic compounds

Question 27

Coenzyme

Answer 27

ORGANIC MOLECULES, such as most vitamins.
INVOLVED IN CHEMICAL PROCESS.

Question 28

Inhibitor

Answer 28

A chemical that interferes with an enzyme’s activity.

Question 29

Competitive Inhibitors

Answer 29

Block substrates from entering the active site and reduce an enzymes productivity.

Question 30

Noncompetitive Inhibitors

Answer 30

Bind to the enzyme somewhere other than the active site.
Change the shape of the active site.
Prevent the substrate from binding.
PASSIVE

Question 31

Allosteric Regulation of Enzymes

Answer 31

Either inhibit or stimulate an enzyme activity.
Occurs when a regulatory molecule binds to a protein at one site and affects the protein’s function at another site.
Prevents wasting energy
Maintains Homeostasis

Question 32

Feedback Inhibition

Answer 32

Final product of the metabolic pathway can be used as a noncompetitive inhibitor for the first enzyme, which will shut down the metabolic pathway.
*prevents a cell from wasting chemical resources.