Chapter 5

Question 0

Is the energy in a “high-energy” food bar kinetic or potential?

Answer 0

• potential

Question 1

Define energy and tell the difference between kinetic and potential energy.

Answer 1

• ability to do work
• kinetic energy in energy if motion
• potential energy is stored energy

Question 2

State the first law of thermodynamics.

Answer 2

• energy can change from one state to another. But it can’t be destroyed or made new

Question 3

State the second law of thermodynamics.

Answer 3

• Disorder is more likely then order

* it takes more energy to be orderly the to be disorderly

Question 4

When an organism dies, what happens to its entropy?

Answer 4

• It’s entropy increases

Question 5

Differentiate between endergonic and exergonic reactions.

Answer 5

• Endergonic needs energy to react like pushing a boulder up a hill
• Exergonic spontaneous energy like a boulder that has rolled down a hill

Question 6

If exergonic reactions tend to occur spontaneously, why haven’t they all done so? What stops the world’s gasoline from burning?

Answer 6

• Because it requires an input of energy to get started

Question 7

Define activation energy and catalysis (catalyst).

Answer 7

• Activation energy is a chemical nudge

* Catalysis lowering the activation energy of a reaction

Question 8

Differentiate between active site and substrate binding site.

Answer 8

• Active site the enzyme surface that the reactant fits

* Binding site the site of the reactant that fits into the enzyme

Question 9

Describe how an enzyme lowers the activation energy of a chemical reaction.

Answer 9

• The enzyme weakens the bond be taking away some of its electrons

Question 10

Explain the effects of temperature and pH on enzyme-catalyzed reactions.

Answer 10

• Temperature the enzymes shape is too weak to hold the proper position
• pH the shape determining the polar interactions of enzymes are sensitive to the hydrogen ion

Question 11

Explain how hotsprings bacteria can live in near-boiling water (158oF = 70oC that would kill a human bather.

Answer 11

• The enzymes are more stable allowing the enzymes to function at much higher temperature

Question 12

Describe how repressors interact with allosteric sites of enzymes and the results of this interaction.

Answer 12

• Repressor alters the shape of the enzymes active site such that it cannot bind the substrate

Question 13

Explain how the phosphate groups of ATP store potential energy, and how organisms use this energy to power endergonic reactions.

Answer 13

• like someone investing into stocks they put the energy in to get useful energy out
• cells convert the energy found in food molecules like sugar into ATP though cellular respiration