Wk 2- Biochemistry (atoms)

Atom structure Atoms are made of - , -, - • and - are inside the atoms nucleus • orbit on valence shells The combined amount of - ,- = the atomic mass

Atomic stability Atoms want to be stable Atoms with a - valence shell of electrons = - / inert, unreactive Atoms without a - valence shell = - /- Valence shells have an - number of electrons to be stable

Valence shells Usually have - rings / shells - electrons in the first shell and - in the next 2 shells Atoms can have up to 1- shells

Reactivity Atoms want to be stable. To do this they -,- and - electrons.

Atomic structure Protons carry a - charge Neutrons carry a - charge Electrons carry a - charge

Ions : the process of becoming stable Gaining/ losing / sharing Ions have an - - number of protons and electrons Cation = ?charged They have more - than - as they - electrons Anion= ? charged They have more - than - as they - electrons

Chemical bonds What are the 3 chemical bonds ?

Ionic bonds Are not strong bonds , they form between ions. Ions are held together by an - charge + charged ions = ? - charged ions = ?

Covalent bonds Covalent bonds are the strongest bonds They are the - common in the human body Covalent bonds are made when 2+ atoms - electrons Single covalent bonds = - electrons are shared Double covalent bonds = - electrons are shared

Covalent bonds Can be either - or non - - is - sharing of electrons Non - is - sharing of electrons

Sharing electrons Polar bonds : Unequal sharing of electrons The larger atom has - time of the electron in the shell orbit which creates -/- areas of an atom The larger atom dominates the - time

Sharing electrons Non polar bonds: Non polar bonds have - sharing of the electron Similar - atoms have - attraction

Hydrogen bonds Are the weakest bonds They are the most - in - organisms - molecules use hydrogen bonds Negative and positive areas in the polar areas of atom attract each other (like a battery +-)

Matter exists in three main states. What are they? Atoms and molecules are composed of matter S? L? G?

The human body contains 2? Elements. What are the main 4 elements? 1. C? 2. O? 3. H? 4. N?