Molecular structure of lipids. Surface tension

Question 1

Molecular structure of lipids

Answer 1

> molecules close to each other
large molecular forces of attraction exist
fluidity- ability to be moved in a particular direction by relatively small forces

Question 2

Quasicrystalline structure of lipids

Answer 2

> molecules oscillate about an equilibrium node for a short period of time and then jump to another node
relaxation time depends on the ….

Question 3

Van der waals forces

radius of action r

Answer 3

Radius of action r- smallest distance between two molecules at which the van der waals forces become small enough to be neglected

Question 4

Van der waals forces

Sphere of molecular action

Answer 4

a sphere centred at the molecule and with radius, equal to the radius of action of that molecule

Question 5

Intermolecular forces

Answer 5

the molecules is pulled equally in all directions by neighbouring liquid molecules, resulting in a zero net force

Question 6

Intermolecular forces

Cohesion force

Answer 6

the net force fk on the molecule is not zero, it is normal to the free surface and is directed inwards.

Question 7

Cohesion pressure pk

Answer 7

the sum of the cohesion forces acting on all molecules in unit area of the surface layer of the liquid
> keeps liquids compressed
> For water= pk 10^9 pa

Question 8

Energy of the molecules

Answer 8

in the book

Question 9

Surface tension

Answer 9

> The molecules in the surface layer interact with forces, parallel to the free surface