GS-1 Revision Points

Question 1

Where are ribosomes found ?

Answer 1

In the Cytosol or associated with the Rough ER

Question 2

How are enzymes named ?

Answer 2

Usually relating to function e.g. Esterase cleaves an ester bond in translation

Question 3

Describe the graphs representing concentration over time for 0, 1st and 2nd Order reactions

Answer 3

Question 4

What is the result when a log is taken of an exponential curve ?

Answer 4

A straight line

Question 5

What is one Picogram ?

Answer 5

One trillionth (10^-12) of a gram

Question 6

What happens is Eº is < 0 ?

Answer 6

Eº is the standard reduction potential, if this is less than 0, the reaction will not be spontaneous.

Question 7

What is the Bernoulli effect ?

Answer 7

Question 8

What is Newton’s third law ?

Answer 8

For every action there must be an equal and opposite reaction

Question 9

Define Flow

Answer 9

Volume per unit time

Question 10

Sketch a diagram of pressure and velocity, for a fluid in laminar flow

Answer 10

Question 11

What is the flow rate of laminar flow ?

Answer 11

It is constant

Question 12

What happens to the solubility of a gas when the pressure over the solution is decreased ?

Answer 12

Question 13

What happens to the solubility of a gas when temperature is increased ?

Answer 13

the solubility decreases

Question 14

How do you calculate percentage mass ?

Answer 14

Question 15

How would you derive which indicator is most appropriate for a pH change of a reaction ?

Answer 15

The indicator must change colour in a range which includes the end point of the reaction.

Question 16

What is pK_a ?

Answer 16

The acid dissociation constant - it is the negative log of K_a

Therefore, when pK_a is high, K_a is low, and vice versa

Question 17

What happens to the pK_b of the conjugate base, if K_a is low ?

Answer 17

The pK_b of the conjugate base will be the opposite of the conjugate acid, therefore pK_a will be high, and pK_b will be low.

Question 18

If a reaction normally uses a catalyst, but it is removed, what would be the impact on the partial pressures of the reactants at equilibrium ?

Answer 18

No effect, because catalysts only change the rate of the reaction, not the equilibrium position itself.

Question 19

Descibe Le Chateliers principle

Answer 19

Question 20

With regard to an organisms survival, genetic mutations are usually… ?

Answer 20

Negative or neutral

Question 21

What is a cumulated Diene ?

Answer 21

Where the multiple double bonds share a common Carbon atom.

Question 22

What is a conjugated diene ?

Answer 22

Conjugated double bonds separated by single bonds, E.g. 1,3 Butadiene

Question 23

What is an unconjugated Diene ?

(Also known as an Isolated Diene)

Answer 23

Double bonds are separated by two or more single bonds, they are usually less stable than isomeric conjugated dienes

Question 24

Describe the Diels-Alder Diene conformation ?

Answer 24

Must be Cis conformation, with two double bonds on the same side of the single bond.

Question 25

How many conjugated Dienes are shown below ?

Answer 25

1

Only the 2nd structure represents 2 double bonds separated exactly by one single bond

Question 26

Which of the following is NOT a pair of resonance structures ?

Answer 26

IV

Question 28

How would you calculate refractive index ?

Answer 28

Question 29

What happens to velocity and wavelength when light travels from one medium to another with a different refractive index ?

Answer 29

Velocity and Wavelength also change

Question 30

What happens to the intensity of a light ray as it passes through a medium other than air ?

Answer 30

Its velocity decreases in the medium leading to a loss of energy

(N.B. Intensity is the rate of energy propagation through space)