biological compounds 1.1 (lipids) Flashcards
What are the functions of lipids?
-thermal insulation
-protection from physical damage
-energy store
Explain the thermal insulation that lipids offer
in mammals, adipose tissue underneath the skin helps to reduce heat loss
Explain how lipids can be used as an energy store
gram for gram lipids provide more than twice the amount of energy as carbohydrates, about 38 kJ/g
Explain how lipids offer protection from physical damage
Adipose issue around delicate organs such as the kidneys acts as a cushion against physical damage
What are waxes?
-Similar to lipids, but also contain alcohol (R-OH)
-Insoluble
-Leaves and insects use waxes as a method to minimise water loss
What is the structure of triglycerides?
One glycerol and three fatty acids
What is an unsaturated fat?
They have a double bond in the hydrocarbon side chain (shown as a kink in the displayed formula)
Is saturated fats good for you?
Saturated fats are linked to heart disease
What are the states of saturated and unsaturated fats at room temperature?
saturated fats- solid
unsaturated fats- liquid
What types of cholesterol are there and which type is bad for you?
-High density lipoproteins (HDL) and Low density lipoproteins (LDL)
-LDL is bad as it contains a high amount of cholesterol, it gets deposited in blood vessels and can lead to atheromas
Wh is HDL referred to as the good cholesterol?
-It contains less cholesterol and doesn’t lead to atheromas
-It takes cholesterol to the liver to be broken down
What is the structure of a phospholipid?
a Glycerol, a phosphate head (-), two fatty acids
What are the properties of a phosopholipid?
-Hydrophilic head
-Hydrophobic tail
What are the functions of phospholipids?
Forms lipid bilayer (cell and organelle membranes)
What is the test for lipids?
emulsion test
positive result: cloudy white emulsion
