organic chem Flashcards
describe drugs
substances which alter biochemical processes in the body
describe medicines
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
what are receptors?
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
what are agonists?
mimic the natural compound and bind to the receptor to produce a response similar to th enatural active compound (produce drug action/ effect)
what are antagonists?
prevent the natural compiund from binding to the receptor, and so blocks the natural response from occuring (no drug action/ effect)
what is a pharmacophore?
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
what has to be just right so that the drug can interact with the receptor binding site or the active site of an enzyme?
the overall shape + size of the drug
what are the different types of bonds that can be formed between the drug and receptor?
- ionic bonds
- LDFs
- PD-PD i
- Hydrogen bonds
many drugs that act on enzymes are classified as what?
enzyme inhibitors
what do enzyme inhibitors do?
act on enzymes by binding to their active site and blocking the reaction normally catalysed there
how do you calculate % solution by mass?
% mass = mass of solute/ mass of solvent x100
how do you calculate % volume by mass?
% volume = volume of solute/ volume of solvent x100
what are parts per million (ppm)?
1mg per kg or 1mg per l
what are atomic orbitals?
regions of space where electrons are most likely to be found
what happens when atoms approach eachother (in terms of A.Os)
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
what are atomic orbitals described as and what to they do?
they are described as wave functions, combining constructively and destructively
describe the bonding molecular orbitals
- 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
describe the anti-bonding molecular orbitals
- 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
what is a sigma δ bond?
a covalent bond formed by an end-on overlap of 2 atomic orbitals lying along the axis of the plane
what is a pi π bond?
a covalent bond formed by the sideways overlap of 2 parallel atomic orbitals lying perpendicular to the axis of the bond
which is more efficient- side-on (π) or end-on (δ) overlap?
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
what is hybridisation?
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
what is sp³ hybridisation?
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
what type of bonding is found in alkanes?
bonding in alkanes can be described in terms of sp³ hybridisation and δ bonds
what is sp² hybridisation?
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
what type of bonding is found in alkenes?
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
