organic chem

Question 1

describe drugs

Answer 1

substances which alter biochemical processes in the body

Question 2

describe medicines

Answer 2

drugs which have a benificial effect are used in medication. a medicine usually contains the drug and other ingrediants such as fillers to add bulk or sweeteners to improve the taste

Question 3

what are receptors?

Answer 3

proteins on the surface of cells that interact with small biologically active molecules to produce a response
they can also be enzymes that catalyse chemical reactions

Question 4

what are agonists?

Answer 4

mimic the natural compound and bind to the receptor to produce a response similar to th enatural active compound (produce drug action/ effect)

Question 5

what are antagonists?

Answer 5

prevent the natural compiund from binding to the receptor, and so blocks the natural response from occuring (no drug action/ effect)

Question 6

what is a pharmacophore?

Answer 6

the structural fragment of a drug molecule which allows it to form interactions with a receptor binding site or an enzyme active site.
it normally consists of different functional groups correctly orientated with respect to eachother

Question 7

what has to be just right so that the drug can interact with the receptor binding site or the active site of an enzyme?

Answer 7

the overall shape + size of the drug

Question 8

what are the different types of bonds that can be formed between the drug and receptor?

Answer 8

1. ionic bonds
2. LDFs
3. PD-PD i
4. Hydrogen bonds

Question 9

many drugs that act on enzymes are classified as what?

Answer 9

enzyme inhibitors

Question 10

what do enzyme inhibitors do?

Answer 10

act on enzymes by binding to their active site and blocking the reaction normally catalysed there

Question 11

how do you calculate % solution by mass?

Answer 11

% mass = mass of solute/ mass of solvent x100

Question 12

how do you calculate % volume by mass?

Answer 12

% volume = volume of solute/ volume of solvent x100

Question 13

what are parts per million (ppm)?

Answer 13

1mg per kg or 1mg per l

Question 14

what are atomic orbitals?

Answer 14

regions of space where electrons are most likely to be found

Question 15

what happens when atoms approach eachother (in terms of A.Os)

Answer 15

the atomic orbitals merge to form molecular orbitals. the number of molecular orbitals formed is always equal to the number of atomic orbitals that combine

Question 16

what are atomic orbitals described as and what to they do?

Answer 16

they are described as wave functions, combining constructively and destructively

Question 17

describe the bonding molecular orbitals

Answer 17

• δ
• is lower in energy and filled faster
• occupies the region between the two nuclei
• covalent bonding
• the attraction of positive nuclei to negatie electrons occupying bonding molecular orbitals is the basis of bonding between atoms

Question 18

describe the anti-bonding molecular orbitals

Answer 18

• δ*
• is a higher energy molecular orbital
• is usually empty
• electrons can be promoted into it
• filling results in instability
• each molecular orbital can accomodate max. 2 electrons

Question 19

what is a sigma δ bond?

Answer 19

a covalent bond formed by an end-on overlap of 2 atomic orbitals lying along the axis of the plane

Question 20

what is a pi π bond?

Answer 20

a covalent bond formed by the sideways overlap of 2 parallel atomic orbitals lying perpendicular to the axis of the bond

Question 21

which is more efficient- side-on (π) or end-on (δ) overlap?

Answer 21

end-on overlap of orbitals is much more efficient than side-on overlap. as a result, sigma bonds are much stronger than pi bonds

the electrons in a pi bond are much less exposed to attack from electrophilic reagents

Question 22

what is hybridisation?

Answer 22

the process of mixing atomic orbitals within an atom to generate a set of new degenerate orbitals called hybrid orbitals- the shape can minimise electron pair repulsion

Question 23

what is sp³ hybridisation?

Answer 23

1 s and 3 p orbitals combine to form 4 hybrid orbitals. they lie at the corners of a regular tetrahedron
to minimise electron pair repulsion, the shape of the molecule is tetrahedral with a bond angle of 109.5º

Question 24

what type of bonding is found in alkanes?

Answer 24

bonding in alkanes can be described in terms of sp³ hybridisation and δ bonds

Question 25

what is sp² hybridisation?

Answer 25

1 s and 2 p orbitals mix to give 3 sp² hybrid orbitals
the orbitals lie at the corner of a plane triangle. therefore the molecule is triangular planar with a bond angle of 120º

Question 26

what type of bonding is found in alkenes?

Answer 26

bonding in alkenes can be described in terms of sp² hybridisation and BOTH δ and π bonds
the π bond prevents free rotation between the carbon atoms