Biological molecules: Lipids

What is a lipid + functions (5)

What is a lipid + functions (5)

An organic molecule that is used for thermal insulation (eg in adipose layer under skin)

in seeds (2x as much energy as carbohydrate = 2x lighter. Can spread further when germinating)

As storage of energy

Source of metabolic water (released during respiration)

Protection from impact damage (eg around kidneys)

Most common type of lipid

triglyceride

Why aren’t lipids polymers

Composed of glycerol and fatty acids. Structures not similar enough

Chemical formula for glycerol

C₃H₈O₃

Draw glycerol

Draw saturated fatty acid

Are fatty acids hydrophobic or hydrophilic

Hydrophobic because hydro carbon chain is non-polar

repels water

what makes up a fatty acid?

hydrocarbon chain, carboxylic acid group

Draw an unsaturated fatty acid

Unsaturated fatty acid properties

Alkene (double bond)

Lower melting point = liquid at room temp eg. oils

Has kinks / bends in hydrocarbon chain

What type of bond is precent in a triglyceride

Ester bond (intramolecular)

What polarity is glycogen

Polar = hydrophilic

attracts water

Draw a phospholipid diagram

What is a phospholipid + function

Glycerol molecule + 2 fatty acids + phosphate group

components of plasma (cell) membranes

greater the number of unsaturated fats, greater the fluidity

draw drawing of phospholipid + phospholipid layer

What is a diet of a lot of saturated fatty acids associated with?

Coronary heart disease

saturated fatty acid properties

alkane

only single bonds in hydrocarbon chain

higher melting point: solid at room temperature

the more of these in a membrane, the less fluid it is

what kind of reaction forms a triglyceride?

condensation reaction

what is a condensation reaction?

creates a triglyceride

glycerol + 3 fatty acids = triglyceride

glycerol + 2 fatty acids + phosphate group = phospholipid

water is removed