MEDICINAL CHEMISTLY 1ST YEAR
2025 \2026 WITH FULLY EXPAINED
STUDY GUIDE
Node - ANSWER✔✔✨---An area in an orbital where the probability of finding an electron is zero.
Also the part of a wave where there is no transverse motion.
Degenerate orbitals - ANSWER✔✔✨---orbitals that have the same energy e.g the 3 2p orbitals
De Broglie - ANSWER✔✔✨---Scientist who suggested that all moving particles had a wave motion
associated with them. This is the basis for electrons having wavelike properties
Why is pH of drugs important? - ANSWER✔✔✨---- Influences the ionisation state of the drug in
different bodily fluids which changes how it is abosrbed
- E.g drugs with basic side chains can gain protons and become positively charged
Hydrophobic/Hydrophilic drugs. - ANSWER✔✔✨---The ionisation state of the drug affects if it is
hydrophilic or hydrophobic which in turn affects membranes it can cross. Like dissolves like, so only a
hydrophobic drug (no charge) can cross hydrophobic membranes.
Arrhenius theory (acids and bases) - ANSWER✔✔✨---Acid - Any substance that produces H+
Base - Any substance that produces OH-
Bronsted-Lowry theory (acids and bases) - ANSWER✔✔✨---Acid - Any substance that donates a
proton
Base - Any substance that accepts a proton
When they react with this theory, a conjugate base and conjugate acid is formed.
In this theory, water is amphoteric.
, Lewis theory (acids and bases) - ANSWER✔✔✨---Acid - electron pair acceptor
Base - electron pair donor
Sorenson's pH scale - ANSWER✔✔✨---- measures hydronium ion concentration
- logarithmic scale, the p stands for -log10
- pH = -log10 [H3O+]
pOH - ANSWER✔✔✨----log[OH-], used to measure the OH- concentration
Strong acids and bases - ANSWER✔✔✨---completely ionise in aqueous solution
Kw - ANSWER✔✔✨---dissociation constant for water. at 25 degrees celcius this is 1x10^-14
Weak acids and bases - ANSWER✔✔✨---Only partially ionise in aqueous solution
pKa - ANSWER✔✔✨----logKa.
Ka = 10^-pKa
pKa is often used to tell the strength of an acid. The stronger an acid, the lower the pKa
Henderson-Hasselbalch equation - ANSWER✔✔✨---pH = pKa + log [A-]/[HA]
Conjugate base stability - ANSWER✔✔✨---The more stable the conjugate base, the stronger the
acid
The stability of the conjugate base is affected by:
- electronegativity (more electronegative = Stronger acid)
- Anion size (larger anion = more stable CB = stronger acid)
- Delocalisation (more delocalisation of electrons = stronger acid)
2025 \2026 WITH FULLY EXPAINED
STUDY GUIDE
Node - ANSWER✔✔✨---An area in an orbital where the probability of finding an electron is zero.
Also the part of a wave where there is no transverse motion.
Degenerate orbitals - ANSWER✔✔✨---orbitals that have the same energy e.g the 3 2p orbitals
De Broglie - ANSWER✔✔✨---Scientist who suggested that all moving particles had a wave motion
associated with them. This is the basis for electrons having wavelike properties
Why is pH of drugs important? - ANSWER✔✔✨---- Influences the ionisation state of the drug in
different bodily fluids which changes how it is abosrbed
- E.g drugs with basic side chains can gain protons and become positively charged
Hydrophobic/Hydrophilic drugs. - ANSWER✔✔✨---The ionisation state of the drug affects if it is
hydrophilic or hydrophobic which in turn affects membranes it can cross. Like dissolves like, so only a
hydrophobic drug (no charge) can cross hydrophobic membranes.
Arrhenius theory (acids and bases) - ANSWER✔✔✨---Acid - Any substance that produces H+
Base - Any substance that produces OH-
Bronsted-Lowry theory (acids and bases) - ANSWER✔✔✨---Acid - Any substance that donates a
proton
Base - Any substance that accepts a proton
When they react with this theory, a conjugate base and conjugate acid is formed.
In this theory, water is amphoteric.
, Lewis theory (acids and bases) - ANSWER✔✔✨---Acid - electron pair acceptor
Base - electron pair donor
Sorenson's pH scale - ANSWER✔✔✨---- measures hydronium ion concentration
- logarithmic scale, the p stands for -log10
- pH = -log10 [H3O+]
pOH - ANSWER✔✔✨----log[OH-], used to measure the OH- concentration
Strong acids and bases - ANSWER✔✔✨---completely ionise in aqueous solution
Kw - ANSWER✔✔✨---dissociation constant for water. at 25 degrees celcius this is 1x10^-14
Weak acids and bases - ANSWER✔✔✨---Only partially ionise in aqueous solution
pKa - ANSWER✔✔✨----logKa.
Ka = 10^-pKa
pKa is often used to tell the strength of an acid. The stronger an acid, the lower the pKa
Henderson-Hasselbalch equation - ANSWER✔✔✨---pH = pKa + log [A-]/[HA]
Conjugate base stability - ANSWER✔✔✨---The more stable the conjugate base, the stronger the
acid
The stability of the conjugate base is affected by:
- electronegativity (more electronegative = Stronger acid)
- Anion size (larger anion = more stable CB = stronger acid)
- Delocalisation (more delocalisation of electrons = stronger acid)
