Cellular Respiration Review

Question 1

Energy

Answer 1

The ability to do work

Question 2

Work

Answer 2

When an object moves against an opposing force

Question 3

Metabolism

Answer 3

The sum of all the chemical reactions that occur in the cell

Question 4

Anabolism

Answer 4

When smaller molecules come together to form larger ones (requires energy)

Question 5

Catabolism

Answer 5

When larger molcules are broken down into smaller ones (releases energy)

Question 6

The first Law of Thermodynamics

Answer 6

• The amount of energy in the universe is constant
• Energy cannot be created nor destroyed, only transformed from one form to another

Question 7

Exothermic Reactions

Answer 7

• Energy is released to the surroundings when forming bonds
• The amount of PE in the reactants is greater than in the products –> stronger bonds in products

Question 8

Endothermic Reactions

Answer 8

• Energy is absorbed from the surroundings when breaking bonds
• The amount of PE in the products is greater than the reactants –> weaker bonds in products

Question 9

The Second Law of Thermodynamics

Answer 9

• The amount of entropy in the universe or a system + surroundings increases over time
• The universe becomes more disorganized over time –> every energy conversion is not perfectly efficient

Question 10

Entropy

Answer 10

A measure of the disorder or randomness in a system
High entropy –> a lot of disorder
Low entropy –> less disorder

Question 11

Waste Energy

Answer 11

When energy is being transferred, some of it is always lost usually in the form of heat (thermal energy) this energy lost cannot be used –> waste energy

Question 12

Spontaneous Change

Answer 12

A process that once it starts, it keeps going without the need of extra energy
Spontaneous –> fire
Non- Spontaneous –> boiling water

Question 13

Gibbs Free Energy

Answer 13

Measures the amount of energy that is available to do work - look at the differences in the energy at the beginning vs after the reaction

• ΔG –> exothermic (Spontaneous)
  + ΔG –> endothermic (Non- spontaneous)

Question 14

Exergonic

Answer 14

Gives off free energy

Question 15

Endergonic

Answer 15

Requires free energy

Question 16

ATP

Answer 16

• The main energy carrier in all living cells
• Composed of 1 ribose sugar bonded to 1 adenine (nitrogenous base) and 3 phosphate groups.
• The last phosphate group bond is high in energy

Question 17

ATP Hydrolysis

Answer 17

• When ATP becomes hydrolyzed (addition of water) it becomes ADP and an inorganic phosphate (Pi)
• The energy that is released through this process can be used for cellular functions

Question 18

Energy Coupling

Answer 18

The process by which cells use the energy released from one reaction to drive another reaction that requires energy.

Question 19

Regeneration of ATP

Answer 19

Combining ADP and Pi to regenerate ATP is an endergonic reaction → it
requires free energy which comes from the food that we eat (glucose - a lot of free energy)

Question 20

Phosphorylation

Answer 20

The ATP will transfer its terminal phosphate a molecule → energizes it, giving it the ability to do work.

Question 21

Enzymes

Answer 21

Biological catalysts that speed up a chemical reaction by lowering the activation energy needed for a reaction to occur.

Question 22

Enzyme Substrate Complex

Answer 22

Enzymes bond to specific molecules called substrates at their active sites, forming this complex that facilitates the chemical reaction.

Question 23

Inhabitors

Answer 23

molecules that decrease enzyme activity

Question 24

Competitive Inhibition

Answer 24

• An inhibitor competes with a substrate for the active sight. (reversible)
• Reduces the enzyme’s activity by blocking the substrate from binding.

Question 25

Non-Competitive Inhibition

Answer 25

• An inhibitor binds to a different site on the enzyme.
• Changes the enzyme’s shape so substrate cannot bind.

Question 26

Allosteric Activators

Answer 26

An activator binds to a different site on the enzyme.

Changes the enzyme’s shape to make it work better and speed up the reaction.

Question 27

Rapid oxidation

Answer 27

(combustion)
→ releases energy all at once in the form of heat which is inefficient for biological processes.
→ Burning sugar releases energy all at once, there is a lot of wasted energy

Question 28

Controlled oxidation

Answer 28

(cellular respiration)
→ involves a series of steps that release energy gradually. This is more efficient, allowing cells to capture the energy for ATP production and minimize the amount of waste energy as heat
→ Sugar is broken down slowly and efficiently, so energy can be stored and used instead of being lost as heat