Molecular Interactions. Or, Chemistry class in one lecture!. Key Concepts. Elements, Atoms, Isotopes etc. Chemical formulas, Chemical bonds pH scale, acids/bases Organic Chemistry / Biochemistry. Element = Building block of matter. In human: 11 major essential elements C, O, H
Or, Chemistry class in one lecture!
Heavy water = ?
3 types of radiation:
radiation - In beta decay, a neutron in the nucleus spontaneously turns into a proton, an electron, and a third particle called an antineutrino. The nucleus ejects the electron and antineutrino, while the proton remains in the nucleus. The ejected electron is referred to as a beta particle.
diagnosis & treatment of disease.
127I is “normal” iodine
131I has 4 extra neutrons
Beta radiation, consisting of electrons, is halted by an aluminium plate.
Gamma radiation is eventually absorbed as it penetrates a dense material. Lead is good at absorbing gamma radiation, due to its density.
Atoms must be neutral
Atoms/molecules that are stable will not bond with other atoms/molecules.
Each electron shell can hold a specific number of electrons
The electrons are shared equally
If two electrons are shared, that is a “double bond.”
Non-polar covalent molecules
Consequence: ions and polar molecules dissolve well in water
Are call Electrolytes
are liquid at room temp.
Trans fats have added hydrogen (hydrogenated)
Triglycerides: 3 FA + Glycerol
Saturated Unsaturated Polyunsaturated
Cholesterol decreases cell membrane permeability to small water-soluble molecules.
This picture illustrates the hydrophobic core of protein ras p21
The backbone is colored purple, and the hydrophobic
residues are colored green. All the hydrophilic residues in the protein are colored yellow.
mostly suffix -ase
first part gives info on function
Some important characteristics of an enzyme:
Proteolytic Activation (for some)
Cofactors & coenzymes (for some)
Other molecules interacting with enzyme
Which of the following statements about proteins is false?
A polypeptide consists of 100 amino acids. How many peptide bonds does it contain?
Each of the following is a function of proteins except one. Identify the exception.
A fatty acid that contains three double bonds in its carbon chain is said to be
Allosteric modulators:bind to enzyme away from active site change shape of active site (for better or for worse)
= end product inhibition
Competitive inhibitors: bind to active site
block active site
E.g.: Penicillin binds covalently (= irreversibly
to important bacterial enzyme active site)
Small region of the complex 3D structure is active (or binding) site.
Enzymes bind to substrate
Old: Lock-and-key model / New: Induced-fit model
Catalyze same reaction but under different
conditions and in different tissues/organs
Cu, Fe, Mg
conformational change of
Organic molecules (vitamin
derivatives, FADH2 ....)
act as receptors & carriers
for atoms or functional
groups that are removed
Ions are often called electrolytes!
See Fig 2-7
= simple sugars
= complex CHOs
Biomolecules( = organic molecules associated with living organisms)
2) Fat (lipid)
= partial molecules.
Frequently occur in biological molecules.
Moved around as a single units.
Often make a big difference in the strength or function of a molecule