Chapter 5- Biochemistry (3) Flashcards
Lipids have four main biological roles. What are they?
1- They are components of membranes (phospholipids, cholesterol)
2- They act as energy stores
3- Modifies proteins
4- Lipids serve as hormones.
What are some types of lipids?
1- Fatty acids 2- Triglycerides 3- Phospholipids 4- Steroids 5- Glycolipids
Most fatty acids have an even number of what in their chain?
Carbons
What is a saturated fatty acid?
Where there are no double bonds between carbon atoms in the hydrocarbon tail.
What is an unsaturated fatty acid?
Where there is one or more double bonds between carbon atoms in the hydrocarbon tail.
What fatty acids are straight and what fatty acids bend in their tail?
Saturated fatty acids are straight
Unsaturated fatty acids have bends in their tail
What is a triglyceride?
Triglycerides are 3 fatty acids joined together through an ester bond to glycerol.
How are fatty acids primarily stored?
Fatty acids are stored primarily in adipocytes as a triglyceride
What needs to happen to a triglyceride to release fatty acids?
It needs to be hydrolysed
What is a phospholipid a major constituent of?
The cell membrane
What does a phospholipid contain?
A phospholipid contains 2 fatty acids bound through an ester bond to glycerol. A phosphate group also binds to the glycerol.
All steroid hormones are derived from what?
They are derived from cholesterol except retinoid acid.
Cholesterol is a major component of what?
Cell membranes- it stabilises the phospholipid bilayer and helps maintain the right fluidity of the plasma /cell membrane.
How does cholesterol travel around the body?
Cholesterol travels around the body in lipoproteins
What is a glycolipid?
A complex lipid that contains a sugar.
