macromolecules 1

what are elements?

cannot be broken down or converted into other substances by chemical means

what are atoms?

smallest particle of an element

what are ions?

charged atoms; having gained or lost an electron

how are covalent bonds formed

• two or more atoms share valence electrons to form covalent bonds

• most atoms have unfilled outermost electron shells

• able to donate, accept or share electrons with each other

explain the flexibility of single and double bonds

• single bonds = 2 electrons shared

• rotation is possible

• double bond = 4 electrons shared

• no rotation, rigid

remember the most frequent atoms in biological molecules and how many bonds they can form

• carbon = up to 4 single bonds

• nitrogen = up to 3 single bonds

• oxygen = up to 2 single bond

• hydrogen = up to 1 single bond

describe functional groups and their properties

• hydroxyl group (OH) = polar and acidic

• methyl (CH3) = non polar and basic

• carboxyl (C=O) = polar

• sulfoxide (SH) = polar and acidic

remember types of noncovalent interactions

• ionic interactions

• hydrogen bonds

• hydrophobic forces

• van der waals attractions

explain the impact noncovalent forces on stability and interaction of molecules

• mediates molecular interactions

• allows formation of big complexes

• allows interaction of an enzyme with a substrate

• stabilises macromolecule structures