Lipids

Question 1

What is the difference between saturated and unsaturated fats?

Answer 1

• saturated fats are fats that have single bonds between carbon atoms in the fatty acid chains, making them solid at room temperature
• unsaturated fats are fats that have one or more double bonds between carbon atoms in the fatty acid chains, making them liquid at room temperature

Question 2

What is cholesterol? Why do cells require a source of cholesterol?

Answer 2

• cholesterol is a type of lipid produced in the body
• cells require a source of cholesterol for cell membrane functioning, sex hormone structure, and the synthesis of bile

Question 3

How is cholesterol transported around the body?

Answer 3

• cholesterol is transported around the body as lipoproteins

Question 4

What are saturated fats?

Question 5

What are unsaturated fats?

Question 6

What are monounsaturated fats?

Question 7

What are polyunsaturated fats?

Question 8

What is a phospholipid?

Question 9

What are triglycerides? What are the monomers? How are they formed?

Answer 9

• they are non-polar, hydrophobic molecules
• the monomers are glycerol and (3) fatty acids
• triglycerides are formed by esterification

Question 10

What is an ester bond?

Answer 10

-

Question 11

What is esterification?

Answer 11

• a reaction that produces an ester
• in the formation of a triglyceride a condensation reaction occurs between the carboxyl group of a fatty acid and the hydroxyl group of a glycerol
• this results in an ester bond forming and water is released

Question 12

What is an essential fatty acid?

Question 13

What are lipoproteins? What are the two types of lipoproteins?

Answer 13

• lipoproteins are molecules composed of lipid and protein
• there are two types of lipoproteins; high density lipoprotein (HDL’s) and low density lipoproteins (LDL’s)

Question 14

What are lipids? What are their R group? What do lipids play an important role in?

Answer 14

• lipids are macromolecules that contain carbon, hydrogen and oxygen atoms
• lipids are non-polar and hydrophobic
• lipids play an important role in energy yield, energy storage, insulation and hormonal communication

Question 15

What are LDL’s? What do they contain? What is their role?

Answer 15

• LDL’s (low density lipoproteins) contain saturated fat, cholesterol and protein
• the role = to move cholesterol from liver into blood stream where it remains until required by cells
• they increase blood cholesterol levels when its too low

Question 16

How do LDL’s work? What do high levels of LDL’s lead to?

Answer 16

• LDL’s bind to receptors on cell surface membranes, enabling them to be taken up by the cells that need them and removing cholesterol from the blood
• high levels of LDL’s can lead to blockage of these membrane receptors, causing blood cholesterol to rise

Question 17

What are HDL’s? What do they contain? What is their role?

Answer 17

• HDL’s (high density lipoproteins) contain unsaturated fats, cholesterol and protein
• these molecules transport cholesterol from body tissues to the liver to be recycled or excreted