Hydrogen bonding

Hydrogen bonding

polar molecules are attracted to each other forming hydrogen bonds.

These INTERMOLECULAR forces are weak but VERY important in stabilizing biolological molecules —> DNA,RNA and proteins

water —> covalent bond between oxygen and hydrogen

Attraction bond, —> hydrogen bond Different to a covalent bond

Oxygen becomes slightly negative and the Hydrogen is slightly positive they are ATTRACTED TO EACH OTHER. Represented with a //// dashes between the bond. signifying the attraction.

  • Intermolecular - between molecules

Requirment - it has to occur between two molecules and the polarmolecules must contain O-H F-H. N-H all which have hydrogen.

Hydrogen bonds are intermolcular

Hyrdogen bonding In DNA

  • Hydrogen bonds hold the base pairs together in DNA

  • Hydrogen bonds help proteins to hold their 3D functional Shapes

The hydrogen bonding in water causes water molecules to stick together resulting in

  • High latent Heat —> The energy required to change the state of a substance WITHOUT increasing its temperature. ( The energy needed o melt ice at 0C or boil water at 100C to produce water vapour.)

Latent heat energy ( generated in the body) Evapurates water from sweat and this cools the body.

  • high specific heat

  • A measure amount of energy required to change the temperature of a substance

How much energy is going to be needed?- to raise the temperature by a certain amount

Taking 5 substances and then raising the temperature of said substances to 25 C ( laying something in the sun for the same amount of time, metal will always be hotter because they don't require much heat energy. The more you have of something the harder it will be to heat

  • high surface tension

Water acts as if it has skin on its surface. It attempts to contract to the smallest possible area.

surfactant

In the lungs it moves oxygen INTO the bloodstream, there has to be a smooth surface to do so, if there's condensation, your lungs would be attracted to each other.

Water has HIGH surface tension and our bodies have to counteract it with surfactants ( have to know for exam)

(surfactants are the last thing developed by babies which is why premie babies struggle to breathe sometimes.)

Example of water tension, water likes to stick to it’s self.