Lecture 21

Question 1

Redox reactions are

Answer 1

oxidation and reduction reactions occuring at same time

Question 2

Redox reactions are important becuase

Answer 2

it allows a creation of new lower energy bonds that are more favorable

Question 3

What happens to the left over energy from redox reactions

Answer 3

is its released as heat or work

Question 4

What is an oxidation reaction

Answer 4

A reducing agent with electrons becomes oxidized and gives it electrons away

Question 5

What is a reduction reaction

Answer 5

an oxidizing agent with no or little electrons becomes reduced by gaining electrons

Question 6

Most cellular reactions of biological molecles are Not what

Answer 6

highly exothermic because they have careful control over every transfer

Question 7

KMnO4+ Glycerol reaction is

Answer 7

spontaneous (no energy required)

Question 8

In the KMnO4+glycerol reaction, which is the reducing agent and which is the oxidizing reagent

Answer 8

K+ is the oxidizing reagent
glycerol is the reducing agent

Question 8

biological systems are normally

Answer 8

stable, content where they are

Question 9

How to cause redox reactions in a stable system

Answer 9

need a little energy input to start the process to allow a more stable or possible lower energy bond

Question 10

Are most oxidized state molecules better for giving energy?

Answer 10

No, a more reduced state is better for giving energy because it has free electrons that harness possible energy

Question 11

What is one calorie (cal)

Answer 11

it is the energy needed to heat 1 gram of H2O one degree celsius at 1 atm pressure
ENERGY NEEDED TO CHANGE CHEMICAL RXN

Question 12

what is Calories (Cal)

Answer 12

nutritional information

Question 13

1 Cal = ? calories

Answer 13

1000calories, or 1kcal

Question 14

+∆G is

Answer 14

gained free energy in a system from making complex molecules from simpler ones (~anabolic)

Question 15

-∆G is

Answer 15

lost free energy in a system from breaking complex molecules into simpler ones (~catabolic)

Question 16

+∆G requires

Answer 16

energy, or work input

Question 17

-∆G occurs

Answer 17

spontaneously, doesn’t need any energy input

Question 18

The oxidation of glucose is

Answer 18

highly exergonic (releases energy)

Question 19

Oxidation of glucose occurs by

Answer 19

spontaneously, -∆G of -686 kcal/mol

Question 20

Synthesis of glucose occurs by

Answer 20

work input, +∆G= +686 kcal/mol

Question 21

Relying on flame-driven oxidation of glucose is

Answer 21

incompatible with life and uncontrollable

Question 22

The cellular oxidation of glucose is

Answer 22

more favorable because it is controlled by enzymes and little change in heat

Question 23

What is meta-stable

Answer 23

stable but with the potential to release energy, they are content where they are

Question 24

high energy bonds are

Answer 24

meta-stable

Question 25

All biological reactions require

Answer 25

catalysts

Question 26

Catalysts are

Answer 26

something dramatically increase the rate of the reaction

Question 27

Enzymes are

Answer 27

molecules, proteins, that act as catalysts

Question 28

What is activation energy Ea

Answer 28

The energy required to cause meta-stable molecules to have reactions occur and break bonds

Question 29

What do catalysts specifically do

Answer 29

they lower the activation energy, but they DONT CHANGE ∆G of the reaction

Question 30

Hydrogen peroxide (H2O2) to water (H2O) and oxygen (O2) rxn needs

Answer 30

Fe-carrying catalase enzyme to increase the rate of hydrogen peroxide converting into H2O and O2.
cells cant wait for hours of this reaction and cannot depend on free Fe ions

Question 31

Enzyme activation site

Answer 31

folded amino acid sequence into a protein, causing an activation site where the substrate is attracted to and binds to

Question 32

What happens at the active site of enzymes

Answer 32

substrate binding, activation, and catalysis

Question 33

Enzymes are sensitive to

Answer 33

temperature and pH