Chapter 8

Question 1

Metabolism

Answer 1

All the chemical reactions in an organism

Question 2

Catabolic pathways

Answer 2

-breakdown of molecules into smaller compounds.
-release the energy stored in complex molecules

Question 3

Anabolic pathways

Answer 3

-Building smaller molecules into larger
- Require/absorb energy

Question 4

Energy

Answer 4

capacity to cause change

Question 5

Kinetic energy

Answer 5

the energy of motion

Question 6

Thermal energy

Answer 6

Heat - the kinetic energy of randomly moving atoms or molecules.

Question 7

Potential energy

Answer 7

Stored energy due to arrangement and placement. Ex: a ball at the top of a hill has high potential energy. Because of its position at the top of the hill, the ball can be push and will roll down.

Question 8

Chemical energy

Answer 8

energy stored within bonds, which can be released to do work. Ex: The body breaks apart glucose, the energy released from breaking the bond is used by the body as energy.

Question 9

First law of thermodynamics

Answer 9

Energy cannot be created or destroyed. It can be transformed.

Question 10

Second law of thermodynamics

Answer 10

every energy transformation increases the entropy of the universe

Question 11

Entropy

Answer 11

measure of disorder

Question 12

Free energy

Answer 12

system’s energy available to perform work

Question 13

Exergonic reactions

Answer 13

Energy is released

Question 14

Endergonic Reaction

Answer 14

Energy is absorbed

Question 15

ΔG

Answer 15

Free energy change

Question 16

ΔH

Answer 16

change in Enthalpy

Question 17

ΔS

Answer 17

Change in Entropy

Question 18

Enzymes

Answer 18

Biological catalysts. They speed up metabolic reaction by lowering the activation energy (energy needed to start reaction)

Question 19

Spontaneous

Answer 19

a reaction that occurs without an input of energy. Exergonic reactions are spontaneous

Question 20

energy coupling

Answer 20

the use of exergonic processes to drive endergonic ones

Question 21

Substrates

Answer 21

The substrate binds to the active site of the enzyme

Question 22

Active site

Answer 22

a “pocket” found on the surface of the enzyme. Every active site has a specific substrate that can fit in it.

Question 23

Induced fit

Answer 23

SIMPLY EXPLAINED: the active site “hugs” the substrate. The “hug” puts them closer together, making the enzyme work better.

Actual explanation: Interactions between substrates and active sites causes the enzyme to slightly change shape. This enhances the ability of the enzyme to catalyze the chemical reaction

Question 24

Catalysis in the Enzyme’s Active Site

Answer 24

Some of the surrounding amino acids in the active site have side chains (R chains) that help turn the substrate into the product.

Question 25

denaturing of enzymes

Answer 25

Each enzyme has certain environments that it works best in. Change in pH and temperature can denature the enzyme, meaning it changes its shape, decreasing its function. MAIN FACTORS -Temperature -pH -Chemicals

Question 26

Cofactors

Answer 26

SIMPLE DEFINITION: Cofactors are helper molecules or ions that enzymes need to work properly Actual definition: Cofactors are non-protein molecules or ions that assist enzymes in performing their catalytic functions

Question 27

Coenzymes

Answer 27

organic cofactors ex. vitamins

Question 28

Competitive inhibitors

Answer 28

Binds to the active site of an enzyme. Competes with substrate. Increasing the amount of substrate may overcome this type of inhibition.

Question 29

Noncompetitive inhibitors

Answer 29

binds to another part of an enzyme, causing the enzyme to change shape, and the active site stops working.

Question 30

Allosteric Regulation

Answer 30

Some enzymes have a site called the allosteric site. This is NOT the active site, it is an ADDITIONAL site on the enzyme. An activator binds to the allosteric site to increase the enzyme's activity, while an inhibitor binds to decrease or block the enzyme's activity.

Question 31

Why is allosteric regulation important?

Answer 31

Allosteric regulation turns the enzyme "on" and "off". This regulates metabolic reactions, preventing too much or too little products from being produced.

Question 32

cooperativity

Answer 32

SIMPLER DEFINTION: the binding of one molecules "unlocks" the other active sites on the molecule, increasing enzyme activity ACTUAL DEFINITION: when one molecule binding to an enzyme makes it easier (or harder) for more molecules to bind, affecting how active the enzyme is.

Question 33

Feedback inhibition

Answer 33

SIMPLE DEFINTION: product binds to enzyme, changing its shape, preventing the enzyme from creating more products. The prevents too many products being made. ACTUAL DEFINITION: The end product acts as an allosteric inhibitor of an enzyme early in the metabolic pathway. This prevents overproduction.

Question 34

ATP to ADP

Answer 34

In ATP, a phosphate breaks away, and ATP is now ADP. This releases 7.3 k/cal of energy to be used by the body to do work.