Describe the ways in which LDLs and HDLs affect the formation of atheromas.

Remember that often in A-level exams you can get marks from specific key words and phrases, so first of all try to remember everything you know about the topics in the question (HDLs, LDLs and atheromas).

 

So the key facts that are relevant and we should remember for this question are:

HDLs (or High Density Lipoproteins) carry fats/cholesterol from the liver to tissues.

LDLs (or Low Density Lipoproteins) carry fats/cholesterol from tissues to the liver.

Atheromas are formed from depositions of cholesterol in the artery wall.

 

Then once you have accessed the facts that you (hopefully) learnt from your textbooks then you need to think about how to answer the question clearly and concisely, including all the relevant facts and key words as well as linking them to the question. Learning how to answer exam questions in the way the examiner will like is extremely important for Biology at A-level!

 

So a model answer for this question would be:

LDLs carry cholesterol from the liver to receptors on tissue cells and this causes raised cholesterol levels in the blood. This increases the deposition of cholesterol in artery walls, which increases atheroma formation.

HDLs carry cholesterol from tissues to hepatocytes (the cells found in the liver). This causes the cholesterol levels in the blood to decrease, which reduces the depositions of cholesterol in artery walls, so decreasing the chance of atheroma formation.