Unit 2 Quiz: Glycolysis

Question 1

What are enzymes?

Answer 1

Enzymes are protein catalysts

Question 2

What do enzymes do?

Answer 2

They speed up the rate of specific reactions by lowering the activation energy and the reactants are converted into products faster than without enzyme present (requires less energy to complete reaction line with less of the slope with enzyme requires less)

Question 3

Are enzymes consumed in a reaction?

Answer 3

No, they continue to do work indefinitely

Question 4

Enzymes can only catalyze a single specific reaction T or F?

Answer 4

True

Question 5

Why are enzymes different from other catalysts?

Answer 5

Because they are more delicate organic molecules

Question 6

What deems enzymes useless?

Answer 6

Very high temps or changes in pH alter the 3D structure useless (denaturation deems it useless)

Question 7

What is the early model called when an enzyme and substrate attach to each other?

Answer 7

The lock and key model; suggests an exact fit between an enzyme and a substrate

Question 8

What happens when an enzyme and a substrate come into contact with one another?

Answer 8

The substrate is converted into product and the enzyme is left unchanged

Question 9

Why doesn’t the lock and key model accurately show enzyme action?

Answer 9

When substrate molecule enters active site functional groups interact with functional groups of enzmye

Question 10

What is the currently accepted model for enzyme and substrate action?

Answer 10

Induced-fit model

Question 11

What does the induced model suggest?

Answer 11

That causes the enzyme to change shape to better accommodate the substrate (the enzyme fits around the substrate) then the enzyme goes back to its original shape

Question 12

Why is an enzyme considered a biological catalyst?

Answer 12

They can be used repeatedly and are not wasted after they catalyze a reaction

Question 13

What is the definition of metabolism?

Answer 13

They are chemical reactions that change or transform matter and energy in cells (takes food and makes energy)

Question 14

All reactions in your body (in vivo) and in the universe follow the Laws of…

Answer 14

Thermodynamics (temperature, energy, and entropy) (help predict if the reaction will be spontaneous or not)

Question 15

What is a spontaneous reaction?

Answer 15

It is a reaction that will continue to completion without further energy input once initiated

• Without thinking, without further energy need continued until complete
• Its spontaneous continues with no other energy needed
• Spontaneous to light a match on fire
• Ex. oxidation of glucose

Question 16

What is a non-spontaneous reaction?

Answer 16

• Reaction that can only continue as long as it receives a continual energy input
• Example; electrolysis of water (using an electric current to break down water into oxygen and hydrogen gas)

Question 17

What is exothermic?

Answer 17

Gives off heat occurs spontaneously

Question 18

What is exergonic?

Answer 18

Any energy is given off during rxn

Question 19

What 3 factors will determine if a reaction is spontaneous or not?

Answer 19

Enthalpy: Total energy of a system (kinetic and potential), entropy (a measure of randomness of a system), temperature (a measure of molecular motion)

Question 20

If enthalpy cannot be calculated what good is it?

Answer 20

Not the value of H that matters, its how it changes during a reaction; change in enthalpy can be measured

Question 21

What happens when the change in enthalpy is positive? (absorbs or uses more energy than it releases)

Answer 21

Reaction is endothermic

Question 22

What happens when the change in enthalpy is negative?

Answer 22

The reaction is exothermic (giving off heat and releasing it more negatively)

Question 23

What does an exothermic reaction diagram look like?

Answer 23

Releases products below releases (weight for ex) pushing products to weigh more heat giving off

Question 24

What does an endothermic reaction look like?

Answer 24

Intake products less (weighs less)

Question 25

The change of free energy is delta G
True or False; What does it stand for?

Answer 25

True; Gibbs free energy

Question 26

When delta G is positive…

Answer 26

Reaction is nonspontaneous (needs energy to make reaction)

Question 27

When delta G is negative

Answer 27

Reaction is spontaneous

Question 28

What does biochemical coupling stand for? Where do they occur?

Answer 28

Nonspontaneous reactions require a continual input of energy; to conserve energy spontaneous reactions are used to “drive nonspontaneous reactions; occur on surface of enzyme

Question 29

What is a catabolic reaction?

Answer 29

They are complex substances broken down into something less complex
- Combustion of gasoline (octane) is an example gas to oxygen make water and carbon dioxide (me complex; then I calm down)

Question 30

What is an anabolic reaction?

Answer 30

They are when complex substances are built from something less complex
- Production of sugar (glucose) in photosynthesis is an example:
- carbon dioxide and water make glucose and oxygen

Question 31

What is metabolism in terms of anabolic and catabolic terms?

Answer 31

The sum of all catabolic and anabolic reactions in an organism, these reactions, as all reactions in the universe, follow the laws of thermodynamics (metabolism breaks or builds needed molecules)

Question 32

What is the first law of thermodynamics?

Answer 32

The total amount of energy in the universe is constant; energy cannot be created or destroyed, it can only be converted from one form to another; for ex burning gasoline does not create energy; it just converts potential energy in chemical bonds to heat

Question 33

What is the second law of thermodynamics?

Answer 33

Energy in-universe is spontaneously flowing from higher to lower energy content; the universe is becoming more disordered (entropy is increasing)
for ex wine glass (ordered system) break into pieces (disordered system)m but you will never see the broken pieces reforming into a wine glass on their own

Question 34

Are there any examples in which systems become more ordered? (i.e. entropy, decreases?

Answer 34

A mason building a brick wall? They start with a disorganized pile of bricks and end up with a highly organized wall
- Mason must expand muscular energy to build wall
- Breaks down complex food molecules (like glucose) into simpler molecules and heat
- Net result is overall increase in entropy

Question 35

What do cells use for energy?

Answer 35

Use ATP made up of adenosine and three phosphate groups

Question 36

What does ATP break down into?

Answer 36

ADP, a phosphate group, and a packet of energy through hydrolysis (breakdown by addition of water)

Question 37

Who uses aerobic cellular respiration?

Answer 37

Both plants and animals use this to make ATP when oxygen is present

Question 38

What is aerobic cellular respiration?

Answer 38

Oxygen and glucose react to form carbon dioxide, water, and ATP; occurs in cytoplasm and mitochondria of cells

Question 39

What are two ways that cells can get energy in absence of oxygen…

Answer 39

1. Aneorobic: uses inorganic substances other than oxygen as the final oxidizing agent to produce ATP
2. Fermentation (organic): Uses an organic compound as the final oxidizing agent to produce ATP
   - Alcohol fermentation: glucose from food is converted into carbon dioxide, ethanol (alcohol), and ATP (energy)
   - Lactate fermentation: glucose from food is converted into lactate and ATP (energy)

Question 40

Where does glycolysis take place?

Answer 40

In cytoplasm

Question 41

What type of reaction is glycolysis?

Answer 41

Anaerobic