SPEC POINT 1.15

Question 1

What are Lipoproteins?

Answer 1

1. Lipoproteins are Triglycerides that are surrounded by a layer of Phospholipid, protein and cholesterol.
2. Lipoproteins are how Triglycerides are transported in the blood (because they aren’t soluble in water)
3. Excess energy in diet is converted to LDL’s by liver for fat to be transported to adipose tissues for long term storage
4. When energy stores are used up, fat is released by adipose back into the blood, to be used up in respiration, as HDL

Question 2

What are HDLs?

Answer 2

High density lipoproteins (GOOD CHOLESTEROL)
Contain unsaturated fat, less cholesterol and more protein
Their role is to transport cholesterol from body tissues to the liver where it is excreted
Reduce blood cholesterol levels when too high and are thought to contribute to the removal of cholesterol from fatty plaques

Question 3

What are LDLs?

Answer 3

Low density lipoproteins (BAD CHOLESTEROL)
Contain saturated fat, more cholesterol and less protein
Their role is to move cholesterol from the liver into the bloodstream where it remains until required by cells
They increase blood cholesterol levels when too low, and bind to receptors so they can be taken up by cells
High levels can lead to receptor blockages, creating high blood cholesterol

Question 4

Describe the role of Lipoproteins in CVD:

Answer 4

1. The ratio of HDL to LDL is correlated to CVD
2. A low HDL/LDL ratio is a risk factor for CVD because White blood cells can absorb their saturated fats and cholesterol to become foam cells
3. A high HDL/LDL ratio is thought to have protective effects against CVD