U2 Chapter 8: An Introduction to Metabolism

Question 1

Metabolism

Answer 1

The chemical changes that take place in a cell or an organism. These changes make energy and the materials cells and organisms need to grow, reproduce, and stay healthy. Metabolism also helps get rid of toxic substances

Question 2

Metabolic Pathways

Answer 2

A set of actions or interactions between genes and their products that results in the formation or change of some component of the system, essential for the correct functioning of a biological system

Question 3

Catabolic

Answer 3

Breaking down molecules, releasing energy

Question 4

Anabolic

Answer 4

Building molecules, consuming energy

Question 5

Bioenergetics

Answer 5

The study of the flow of energy through living organisms

Question 6

Energy

Answer 6

The capacity to cause change; some forms of energy do work by moving matter

Question 7

Kinetic Energy

Answer 7

Associated with motion and includes thermal energy which is associated with random motion of atoms or molecules

Question 8

Heat

Answer 8

Thermal energy in transfer from one object to another

Question 9

Potential Energy

Answer 9

Related to the location or structure of matter and includes chemical energy possessed by a molecule due to its structure

Question 10

1st Law of Thermodynamics

Answer 10

Conservation of energy, states that energy cannot be created nor destroyed

Question 11

2nd Law of Thermodynamics

Answer 11

States that spontaneous processes, those requiring no outside input of energy, increase the entropy (molecular disorder) of the universe

Question 12

Free Energy

Answer 12

Energy that can do work under cellular conditions:
Change in Free Energy (<>G) = Enthalpy Change (<>H) - Change in Entropy (T<>S)
- organisms live at the expense of free energy
- at maximum stability, the system is at equilibrium and can do no work

Question 13

Exergonic (spontaneous) Chemical Reaction

Answer 13

The products have less free energy than the reactants (neg <>G)

Question 14

Endergonic (nonspontaneous) reactions

Answer 14

Requires and input of energy (pos <>G)

Question 15

ATP

Answer 15

The cell’s energy shuttle
- Hydrolysis of its terminal phosphate yields ADP and Pi and releases free energy

Question 16

Energy Coupling

Answer 16

The exergonic process of ATP hydrolysis drives endergonic reactions by transfer of a phosphate group to specific reactants, forming a phosphorylated intermediate that is more reactive

Question 17

Activation Energy (Ea)

Answer 17

The energy needed to break the bonds of the reactants
- enzymes lower the Ea barrier
- each enzyme has a unique active site that binds to one or more substrate(s), the reactants on which it acts
- it then changes shape, binding the substrate(s) more tightly [induced fit]

Question 18

Competitive Inhibitor

Answer 18

Binds to the active site

Question 19

Noncompetitive Inhibitor

Answer 19

Binds to a different site on the enzyme

Question 20

Allosteric Regulation

Answer 20

Regulatory molecules, either activators or inhibitors, bind to specific regulatory sites, affecting the shape and function of the enzyme

Question 21

Cooperativity

Answer 21

Binding of one substrate molecule can stimulate binding or activity at other active sites

Question 22

Feedback Inhibition

Answer 22

The end product of a metabolic pathway allosterically inhibits the enzyme for a previous step int he pathway