Chapter 6

Question 1

Define Energy.

Answer 1

The ability to do work or cause change.

Question 2

What are the differences between Potential and Kinetic energy?

Answer 2

Kinetic: energy of motion.
Potential: stored energy.

Question 3

What are the First and Second Laws of Thermodynamics?

Answer 3

1st: energy cannot be created or destroyed but it can be converted from one form to another.
2nd: energy cannot be converted from one form to another without the loss of unusable energy.

Question 4

How do the First and Second Laws of Thermodynamics apply to living things?

Answer 4

1st: an animal walking uses stored energy to kinetically power its muscles releasing excess heat.
2nd: heat that dissipates into the environment cannot be captured and re-used.

Question 5

Define the term “Entropy.” Give an example of why it is important to living things?

Answer 5

Measure of randomness in a system. When entropy occurs, it results in the death of cells.

Question 6

How you decrease entropy? How do you increase entropy?

Answer 6

when heat is added, entropy increases. When heat is removed it decreases.

Question 7

Metabolism

Answer 7

Sum of all chemical reactions that occur in a cell.

Question 8

How are Synthesis Reactions, Degradation Reactions, Exergonic Reactions, and Endergonic reactions related to each other?

Answer 8

e

Question 9

What do ATP, ADP, and AMP stand for?

Answer 9

ATP: Adenosine triphosphate (high energy)
ADP: Adenosine diphosphate (moderate energy)
AMP: Adenosine monophosphate (low energy)

Question 10

Why is ATP so important to a cell?

Answer 10

The cell can only use energy from an ATP molecule.

Question 11

Where is the high energy stored in an ATP molecule?

Answer 11

The three phosphate bonds.

Question 12

How does a cell make ATP?

Answer 12

Cellular respiration.

Question 13

What is a Coupled Reaction? Provide multiple examples.

Answer 13

A coupling reaction occurs when two chemical species of different kinds react with a common intermediate and a catalyst to produce a new product. Photosynthesis is an example.

Question 14

What are the functions of ATP?

Answer 14

Chemical work (synthesis reaction)
Transport work (active transport)
Mechanical work (movement, intracellular and intercellular)

Question 15

What is an Enzyme?

Answer 15

Protein that functions as a catalyst.

Question 16

How does an enzyme influence the Energy of Activation?

Answer 16

Enzymes can reduce the amount of activation energy in reactions.

Question 17

What are enzymes composed of? What are the functions of Enzymes?

Answer 17

Proteins that act as catalysts by speeding up chemical reactions.

Question 18

What factors affect enzymatic rates of reaction?

Answer 18

Temperature, pH, amount of substrate (molecule acted upon by enzyme) or enzyme.

Question 19

Define the term denature.

Answer 19

Permanently changing a proteins shape.
Can happen due to heat increase, or changing the pH.

Question 20

What is an Enzyme Substrate Complex?

Answer 20

A temporary molecule formed when an enzyme comes into perfect contact/shape with its substrate.

Question 21

Explain the Lock and Key Model. How does it differ from the Induced Fit Model?

Answer 21

The enzyme and the substrate possess specific geometric shapes that fit exactly into one another. Enzymes are highly specific. They must bind to a specific substrate before they can catalyze a chemical reaction.

Question 22

What kind of metabolic reactions are controlled by enzymes? Provide an example from lecture.

Answer 22

Photosynthesis, protein synthesis, and cellular respiration.

Question 23

Why is the shape of an enzyme so important?

Answer 23

The shape of the enzyme determines which chemical reaction the enzyme catalyzes.

Question 24

How can you change the shape of a protein?

Answer 24

Temperature increase, changing pH.

Question 25

How does temperature influence enzyme activity?

Answer 25

As the temperature increases, the enzyme activity increases, which increases the reaction rate. Activity is reduced at cooler temperatures. All enzymes have a certain temperature range when they are active, but they work best at certain temperatures.

Question 26

How does pH influence enzyme activity?

Answer 26

Above or below optimum pH leads to decline in reaction rate; extreme changes in pH can cause denaturing but is unpredictable.

Question 27

How does substrate concentration influence enzyme activity?

Answer 27

As substrate concentration increases, so does enzyme activity.

Question 28

How does enzyme concentration influence enzyme activity?

Answer 28

Adding enzymes will speed up a reaction as long as there enough substrate to bond to. When all the substrate is bound the reaction will no longer speed up.

Question 29

What does catalase do? Provide the metabolic reaction that demonstrates the function of catalase. Why is this reaction important to a cell?

Answer 29

Catalase breaks down hydrogen peroxide into water and oxygen. Hydrogen peroxide is fatal to most organisms and needs to be decomposed.

Question 30

Is Carbonic Anhydrase an enzyme? How can you tell?

Answer 30

Yes. Anything ending in -ase is an enzyme.

Question 31

Provide examples of the three basic enzymes associated with digestion or organic molecules.

Answer 31

Lipase: causes hydrolysis of lipids Protease: enzyme used to hydrolyze proteins Amylase: causes starch to form maltose

Question 32

Define the terms Oxidation and Reduction. How do they differ from each other?

Answer 32

Both can be defined in terms of the adding or removing of oxygen to a compound. Oxidation: loses electrons, loses hydrogen ions, gains oxygen Reduction: gains electrons, gains hydrogen ions, loses oxygen

Question 33

Why are Oxidation and Reduction often considered to be "Coupled Reactions"?

Answer 33

An oxidation reaction is always coupled with a reduction reaction. When oxidation losses electrons, a coupled reaction reduction gains those electrons.

Question 34

Provide the balanced equation for photosynthesis and cellular respiration.

Answer 34

Photosynthesis: 6CO2 + 6H2O ->Chloro (energy from sun)-> C6H12O6 + 6O2 produces oxygen and glucose, loses electrons Cellular respiration: C6H12O6 ->Mito-> 6CO2 +6H2O produces carbon dioxide and water, gains electrons

Question 35

Which parts of the equations for photosynthesis and cellular respiration represent Reduction vs Oxidation?

Answer 35

During photosynthesis, CO2 is reduced to glucose, and H2O is oxidized to release O2. In cellular respiration, glucose is oxidized, and oxygen is reduced to form CO2 and water.

Question 36

How do the processes known as oxidation and reduction play a role in photosynthesis and cellular respiration?

Answer 36

In photosynthesis, you are producing glucose and oxygen while losing electrons. In cellular respiration, you are producing carbon dioxide and water while gaining electrons.

Question 37

Reactants

Answer 37

The starting material for a chemical reaction. Reactants go through chemical reactions to form products.

Question 38

Products

Answer 38

Ending materials in a chemical reaction.

Question 39

Synthesis Reactions

Answer 39

Reactions in which two or more substances react to form a single substance (new molecule low complexity to high.)

Question 40

Degradation Reactions

Answer 40

Chemical reactions in which larger molecules are broken down into smaller and simpler molecules.

Question 41

Exergonic Reactions

Answer 41

A chemical reaction that releases energy.

Question 42

Endergonic Reactions

Answer 42

Reaction that absorbs free energy from its surroundings (typically the sun.)