Molecular Orbitals, Colour in Molecules & Pharma

Question 1

pharmacaphore

Answer 1

active structural fragment in medicine that is responsible for desired response and pharmacological activity

Question 2

drugs

Answer 2

a substance that affects biochemical reactions/pathways in the body

Question 3

medicine

Answer 3

a drug taken with the intention of producing a beneficial effect

Question 4

active ingredient

Answer 4

the molecule that initiates the beneficial effect

Question 5

agonist

Answer 5

a medicine that copies/mimics the body’s natural active molecule so when bonded to the receptor site it produces the same response as the natural molecule

Question 6

antagonist

Answer 6

a medicine that strongly binds onto a receptor site but doesn’t initiate a response, instead, it stops the natural active molecule from binding onto the receptor site (for when there is a surplus of natural messengers)

Question 7

how can small active molecules fit and bind to protein receptors in the membrane?

Answer 7

Protein receptors embedded in membranes have hollows or clefts in their surface into which small biologically active molecules can fit and bind

Question 8

how do drugs work?

Answer 8

meds= substrate- can bind to active sites of enzymes (catalytic receptors) within cell
catalytic receptors catalyse reaction on substrate molecule, shape of the binding molecule must complement shape of receptor
after binding hydrogen bonds, LDF forces and ionic bonds hold it in place to stop it from floating away

Question 9

percentage solution by mass

Answer 9

(mass of solute/ mass of solution) x 100

Question 10

percentage solution by volume

Answer 10

(volume of solute/ volume of solution) x 100

Question 11

parts per million

Answer 11

1 mg per kg or 1mg per l

Question 12

why are many organic molecules colourless?

Answer 12

wavelength of light absorbed does not lie in visible region of EMS

Question 13

molecular orbitals form when

Answer 13

bonding and antibonding orbitals overlap

Question 14

HOMO

Answer 14

highest occupied molecular orbital

Question 15

LUMO

Answer 15

lowest unoccupied molecular orbital

Question 16

colour in organic molecules with only single sigma bonds in terms of molecular orbitals

Answer 16

colourless, energy gap between HOMO and LUMO is large and corresponds to UV light, no visible light is absorbed

Question 17

conjugated system

Answer 17

organic molecule containing chain of alternating sigma and pi bonds or benzene rings to allow electrons to be delocalised across many carbon atoms, molecules must contain a large degree of conjugation to be coloured

Question 18

colour in coloured molecules in terms of molecular orbitals

Answer 18

energy is absorbed by delocalised electrons which then moves electrons from HOMO to LUMO, energy gap is in visible region of EMS, colour of compound is complementary to absorbed colour

Question 19

chromophores

Answer 19

group of atoms in a molecule where the difference in energy between HOMO and LUMO falls within the visible region eg. conjugated system, responsible for colour in molecule

Question 20

examples of groups that the extended delocalised system may include

Answer 20

saturated groups like C=C, -N=N-, C=O

Question 21

functional groups that are attached to chromophores to enhance or modify colour

Answer 21

-OH, -NH2, NR2
contain lone pairs of electrons which can become involved in delocalised e- system which can make slight changes to energy difference between HOMO and LUMO