Biology 1 Chapter 8 (Lecture)

Question 1

Cellular Respiration

Answer 1

The process of extracting energy stored in sugars and other fuels.

Question 2

Metabolism

Answer 2

The totality of an organism’s chemical reactions.

Question 3

Metabolic Pathways

Answer 3

A series of chemical reactions that either builds a complex molecule or breaks down a complex molecule in to simpler compounds.

Question 4

Catabolic Pathways

Answer 4

(BREAKDOWN) Breakdown pathways. There is a release of energy by breaking down complex molecules to simpler compounds (e.g. cellular respiration)

Question 5

Anabolic Pathways

Answer 5

(BUILD UP) Consume energy to build complicated molecules from simpler ones; these are sometimes called biosynthetic pathways. An example is the synthesis of protein from amino acids.

Question 6

Energy

Answer 6

The capacity to cause change; a rearrangment of a collection of matter.

Question 7

Kinetic Energy

Answer 7

The energy associated with relative motion of objects.

Question 8

Potential Energy

Answer 8

Energy matter possesses because of its location or structure (e.g. water behind a dam).

Question 9

Heat

Answer 9

A form of thermal energy. It is the kinetic energy associated with random movement of atoms or molecules.

Question 10

Chemical Energy

Answer 10

Potential energy available for release in chemical reaction.

Question 11

Thermodynamics

Answer 11

The study of energy transformations that occur in a collection of matter.

Question 12

The first law of thermodynamics states…

Answer 12

That energy can be Transferred or Transformed, but it cannot be Created or Destroyed.

Question 13

The second law of thermodynamics states that…

Answer 13

Due to a loss of usable energy during energy transfer, that things in the universe tend to go toward Entropy whcih is randomness or disorder.

Question 14

Exergonic Reaction

Answer 14

Proceeds with a net release of energy. These are reactions that occur spontaneously. (-DELTA G)

Question 15

Endergonic Reaction

Answer 15

Is one that absorbs free energy from its surroundings. These reactions are nonspontaneous. Energy is required to drive the reaction. (+DELTA G)

Question 16

A cell does three main kinds of work:

Answer 16

• Chemical Work
• Transport Work
• Mechanical Work

Question 17

Chemical Work

Answer 17

Pushing reactions which would otherwise occur spontaneously (synthesis of polymers from monomers)

Question 18

Transport Work

Answer 18

Pumping of substances across membranes against the direction of spontaneous movement.

Question 19

Mechanical Work

Answer 19

E.G. the beating of cilia or the contraction of a muscle cell

Question 20

Energy Coupling

Answer 20

The use of an exergonic process to drive an endergonic one.

Question 21

ATP

Answer 21

Adenosine Triphosphate

It contains the sugar Ribose, the nitrogenous base Adenine and a chain of 3 Phosphate groups bonded to it.

Question 22

Bonds between phosphate groups of ATP can be…

Answer 22

Hydrolized by adding water. Energy is released when this happens.

Question 23

Coupling

Answer 23

When two reactions can be coupled so that overall, the coupled reactions are exergonic. It involves the transfer of a phosphate group from ATP to some other molecule. The recipient of the phosphate group is said to be Phosphorylated.

Question 24

ATP Cycle

Answer 24

The shuttling of inorganic phosphate and energy

Question 25

Enzymes

Answer 25

Macromolecules (proteins) that acts as a catalyst.

Question 26

Catalyst

Answer 26

A chemical agent that speeds up a reaction without being consumed by the reaction itself.

Question 27

Activation Energy

Answer 27

The initial investment of energy for starting a reaction. The energy required to contort the reactant molecules so the bonds can break.

Question 28

An enzyme catalyzes a reaction by…

Answer 28

Lowering the activation energy enabling the reactant molecules to absorb enough energy to reach transition state even at a moderate temperature.

Question 29

Enzymes cannot make reactions occur that would not…

Answer 29

Normally occur. They just hasten those that would occur anyway.

Question 30

Substrate

Answer 30

The reactant an enzyme acts on.

Question 31

The enzyme binds to the substrate to form

Answer 31

An enzyme-substrate complex.

Question 32

Active Site

Answer 32

A restricted region of an enzyme molecule where the enzyme molecule actually binds to the substrate.

Question 33

How does the temperature effect enzyme activity?

Answer 33

Increases enzyme activity to a certain point.

Question 34

How does pH effect enzyme activity?

Answer 34

Depends on enzyme

Question 35

Cofactors

Answer 35

Nonprotein helpers many enzymes requires for catalytic activity.

Question 36

Coenzyme

Answer 36

If the cofactor is an organic molecule

Question 37

Two types of enzyme inhibitors

Answer 37

• Competitive Inhibitors
• Noncompetitive Inhibitors

Question 38

Competitive Inhibitors

Answer 38

Mimic the substrate and reduces productivity of enzymes by blocking substrates from entering the active sites.

Question 39

Noncompetitive Inhibitors

Answer 39

Impede enzymatic reactions by binding to another part of the enzyme. This causes the enzyme molecule to change shape in a way that the active site becomes less effective.