Unit 2 - Lipids Flashcards
What are the 3 types of lipids?
- Triglycerides
- Phospholipids
- Sterols
What are the 5 functions of triglycerides?
- Major source of energy
- Source of metabolic water
- Makes up adipose tissue
- provides thermal insulation under skin of animals
- Provides protection around internal organs
How do triglycerides compare to carbohydrates in terms of energy?
-Per g triglycerides release more energy
Being a source of metabolic water makes them useful for organisms in what kind of environment?
Desert
Give an example of an animal that uses triglycerides as thermal insulation
Killer whale in the form of blubber
When are triglycerides stored as adipose tissue?
When energy input is greater than energy output
Why is cholesterol transported as a lipoprotein?
They allow lipids and cholesterol to dissolve in the blood
What are the functions of sterols (2 functions)?
-Cholesterol used in cell membranes to give stability and regulate fluidity -Used to make steroid hormones
Give 2 examples of steroid hormones
Testosterone and oestrogen
Where is cholesterol manufactured?
The liver and intestines
What is the function of HDL?
-used to make cell membranes and organelle membranes -decreases membrane fluidity
Which is ‘good’ cholesterol; HDL or LDL?
HDL
What does too much LDL lead to?
-atherosclerosis (deposits in artery walls) -gall stones
How are triglycerides formed?
A condensation reaction between a glycerol molecule and 3 fatty acids
What kind of bonds are formed when a triglyceride is formed?
Ester bonds