6.1

Question 1

Differentiate between kinetic and potential energy.

Answer 1

1. Kinetic energy- energy of motion
2. Potential energy- stored energy

Question 2

Identify the source of energy for the biosphere.

Answer 2

the sun

Question 3

Describe the nature of redox reactions.

Answer 3

2 Chemical reactions act as a coupled redox reaction
 Oxidation- atom or molecule loses an electron
 Reduction- atom or molecule gains an electron (higher level of energy)

Question 4

Explain the first law of thermodynamics.

Answer 4

energy cannot be created or destroyed
 It just changes from one form to another
 During each conversion, some energy is lost as heat

Question 5

Explain the second law of thermodynamics

Answer 5

entropy is continuously increasing
 Energy transformations proceed spontaneously to convert matter from a more ordered (less stable) form to a less ordered (more stable) form

Question 6

Relate free energy changes to the outcome of chemical reactions.

Answer 6

• Positive changes in free energy (positive ΔG)
   More free energy than reactants
   Requires input of energy
   NOT spontaneous
   ENDERgonic
  
  • Absorbs energy
• Negative changes in free energy (negative ΔG)
   Less free energy than reactants
   Spontaneous (may not be instantaneous)
   catabolic
   EXERgonic
  
  • Releases energy

Question 7

how is the course of a reaction with an enzyme catalyst.

Answer 7

 helps destabilize bonds to make the reaction happen easier/faster thus, lowering the activation energy
 ΔG remains unchanged

Question 8

how is the course of a reaction without an enzyme catalyst.

Answer 8

The reaction will take longer than reaction with a catalyst
 Activation energy is unchanged

Question 9

Diagram the structure of ATP

Answer 9

1. Ribose- five-carbon sugar
2. Adenine
3. Chain of 3 phosphates

Question 10

Describe the role of ATP hydrolysis in driving chemical reactions

Answer 10

(exergonic process) drives endergonic reactions by using the energy released in ATP hydrolysis (due to the breaking off of one phosphate), now endergonic reactions have energy to use
* ATP hydrolysis has a ΔG of -7.3 kcal/mol – exergonic reaction
* When you couple ATP hydrolysis with an endergonic reaction you can make the overall coupled reaction exergonic (negative ΔG)