1. Unit 4.3 Review PBS

2. What is cholesterol? What roles does cholesterol play in our cells and in the body
Cholesterol is an important lipid that is made in the liver
It acts as a stabilizer for cell membranes and used for cell to cell communication.
It is a precursor to steroid hormones and Vitamin D
It helps for bile acids, which are important in fat digestion.
It also makes up the myelin sheath around nerve cells to improve the speed of nerve impulses

3. What are LDL and HDL? Job is to carry cholesterol to the cells
HDL – High Density Lipoprotein (made of mostly protein).
Job is to carry cholesterol from the arteries to the liver to be digested
LDL – Low Density Lipoprotein (made of mostly lipids).
Job is to carry cholesterol to the cells

4. How are LDL, HDL, and cholesterol related to heart disease
How are LDL, HDL, and cholesterol related to heart disease? How do doctors interpret the results of a cholesterol test?
High LDL levels carry too much cholesterol to the cells, which then builds up in the arteries.
Low HDL levels means not enough HDL to clear the arteries of the excess LDL.
Build of LDL causes Atherosclerosis, which reduces blood flow and can cause high blood pressure and heart attacks

5. What is familial hypercholesterolemia and how is it inherited?
Mutation of the LDL receptors on the cell membrane, which leads to a build of LDL in the blood stream.
It is an autosomal dominant trait so heterozygotes will still be affected

6. How can techniques of molecular biology be used to analyze DNA for the presence of the FH mutation?
PCR – is used to make many copies of the FH gene
Restriction Enzymes are used to cut the FH Gene. Depending on the bases the enzyme will cut at different places, making different sized fragments, called RFLPs
Gel electrophoresis is used to separate the fragments by size. The negatively charged DNA moves towards the positive end and shorter fragments move farther.
The bands from each person can be compared to controls to identify the genotype that person has.

7. What lifestyle changes may help a patient obtain healthy cholesterol levels?
Limit Trans and Saturated Fat as they increase LDL
Eat unsaturated fats to increase HDL
Exercise daily
Maintain healthy weight
Manage stress and do not smoke
Take medications, like statins if needed

8. What are the pros and cons of using cholesterol lowering medications?
Common cholesterol medication, statins, will decrease LDL, triglycerides, and even CRP (involved in strokes), while slightly elevating HDL
However it can lead to side effects, such as muscle weakness and pain, even in the heart (since it is a muscle)
They can also cause amnesia for minutes to hours, headaches, dizziness, and liver dysfunction

9. How does the heart work as a pump ?
As the heart contracts it pushes on the blood, causing enough pressure to push it through the arteries.

10. What is atherosclerosis
What is atherosclerosis? How can cholesterol plaques affect the overall function of the heart?
Atherosclerosis is the build up of plaque, which can be due to excess LDL along the arterial walls, reducing blood flow
Atherosclerosis of the coronary artery can cause lack of oxygen to fuel the heart
It can cause lack of blood flow to the extremities, including the brain, causing strokes