Atoms, molecules and cells

Make up of the atom

Most of the atom is empty space, made up of subatomic particles

quarks

make up protons and neutrons up - (+2/3e)

down - (-1/3e)

molecule

a group of 2 or more atoms connected by chemical bonds

Chemical bonds

the attraction between atoms causing them to form molecules or crystals

ionic bonds

a bond between a metal and non-metal is called an electrostatic interaction. Ionic compounds form crystals

Covalent bonds

between nonmetal and nonmetal where valence electrons are shared between atoms

metallic bonds

between 2 metals, valence electrons are delocalised within the entire metal and positively charged metal atoms are attracted to the electron sea

van der Waals'

distant dependant interactions - due to transient shifts in electron density generating a transient charge. Negative and positive regions are attracted to each other

hydrogen bonds

bound hydrogen interacts with another atom which has a higher electronegativity

DNA are held together by...

hydrogen bonds

proteins keep their folding thanks to....

hydrogen bonds

Below 4 degrees Celsius water expands

hydrogen bonds become more stable than the kinetic energy of the molecules

cells

the basic units of life which contain heredity information in their DNA. All cells have the same chemical composition and energy flow occur within cells

cells have high efficiency

due to high surface area to volume ratio

high surface area

maximises the exchange and communication with the cell's exterior

at organism level

multicellularity allows for specialisation of function and efficiency

At cell level

compartmentalisation allows for specialisation of function and efficiency