Biology 'Bonds'

Atoms Bond

• Bonding is accomplished by electrons interacting between atoms (due to valence electrons)

• Three important kinds of bonds hold atoms and molecules together

• Ionic bonds

• Covalent bonds

• Hydrogen bonds

(strongest) covalent -> ionic -> hydrogen (weakest)

Ionic Bonds

• Transfer of electrons

• Bond dissociates in water and ions are formed

• Bond of attraction

• Not as many possible combinations

Covalent Bonds

• Sharing of electrons

• Strongest and most stable of bonds

• Infinite combinations

• All important biological molecules are covalently bonded

Hydrogen Bonds

• Attraction between hydrogen atoms of one molecule with a negative region of another molecule

• Very important to living system and the environment

• Give water all of its important characteristics 

• Very important in protein’s 3 dimensional structure

Polarity in Covalent Bonds

• Polarity: the unequal sharing of electrons on a covalent bond

• This leads to unequal distribution of charge in the molecule

• Polar molecules are attached to other polar molecules because they have positive and negative regions

Bonds determine Shape

• Shape is everything in biology

• Structure and function are always related

• Bonding between atoms determine a molecules shape