Biological Molecules - Lipids Flashcards
(21 cards)
What roles do lipids do
Source of energy
Water proofing
Insulation
Protection
Example ofwater proofing ?
Waxy cuticle of leaves
Example of insulation
Thermal
Electrical
(Mylin sheath of nerve cells)
Example of lipids being used as protection
Fat is often stored around delicate organs such as kidney
How do phospholipids contribute to cell membranes
They contribute to the flexibility of the membranes and transfer of lipid soluble substances across them
What are triglycerides ?
Have three (tri) fatty acids combined with glycerol (glyceride)
What kind of bond is formed when a fatty aicid combines with glycerol in a condensation reaction
Ester bond which carbon is single bonded to oxygen and hydrogen then double bonded to oxygen
What is hydrolysis of triglycerides ?
Glycerol and three fatty acids
What do triglycerides consist of ?
Fat {solid at room temp) oils (liquid at room temp)
Structure of triglycerides ?
Insoluble in water low mass to energy ratio
How does triglycerides being insoluble aid their function ?
Energy can be stored in a small volume - no need for large mass
How does triglycerides having high ratio of hydrogen to oxygen atoms ?
Release water when oxidised and provide important source of water for organisms in dry deserts
How does triglycerides being insoluble in water
Osmotically inactive/ water proofing
What are phospholipids ?
Similar to lipids but one fatty acid is replaced by a phosphate molecule
What do fatty acids molecules do ?
Hydrophobic - repel water
What do phosphate molecules do ?
They attract water
What are the two parts phospholipids are made of ?
A hydrophilic head
A hydrophobic tail
What does the hydrophobic head do ?
Interacts with water (attracted to it )but not with fat
What does the hydrophobic tail do ?
It orients itself away from water but mixes with fat
What can the head and tails also be described as ?
Polar and non polar
Explain polar head
They’re are both delta positive and delta negative regions in the head and there is an uneven distribution of electrons
