Fats

Question 1

Lipids

Answer 1

Fatty acids
Triglycerides
Phospholipids
Cholesterol

Question 2

Function of lipids

Answer 2

Provide/store energy
Maintain cell membranes
Produce hormones
Insulation (temperatures) and cushioning (physical)

In food, stimulate rich flavor, and enhance intestinal absorption of fat soluble vitamins

Question 3

Triglycerides

Answer 3

95% of lipids in the body
3 fatty acids attached to a glycerol backbone
Gives energy!
-triglycerides –> fatty acids and glycerol into bloodstream
-glycerol is converted to glucose by liver

Question 4

Sterols

Answer 4

More chemically complex
Carbon rings
Cholesterol: makes Vitamin D, estrogen/testosterone/bile, found in eggs/turkey/ham/salmon

Question 5

Trans fats

Answer 5

Unsaturated fats with >1 trans double bond rather than cis double bond –> raised blood cholesterol levels and increased heart disease risk

Question 6

Hydrogenation

Answer 6

Adding hydrogen atoms into liquid vegetable oil
Partial hydrogenation: not all double bonds are hydrogenated, therefore natural cis double bonds convert to unhealthy trans forms

Question 7

Phospholipids

Answer 7

Chemically similar to a triglyceride, but 1/3 fatty acids replaced by a compound containing phosphorous (hydrophilic) and nitrogen (hydrophobic) groups

Question 8

Lipoproteins

Answer 8

Transport lipids in blood
HDL: high density lipoprotein, or “good cholesterol” - transports cholesterol away from tissues and to the liver to be eliminated

LDL: low density lipoprotein, or “bad cholesterol” - conveys cholesterol to tissues, can contribute to atherosclerotic plaque if oxidized

Question 9

Lipid digestion and absorption

Answer 9

Stomach: minor fat digestion
Liver: produce bile to emulsify fat (break it up so it has more surface area)
Pancreas: secretes pancreatic lipase to SI
Duodenum (upper part of SI): pancreatic lipase digests triglycerides, forming monoglycerides/free fatty acids

Question 10

Arteriosclerosis

Answer 10

Loss of arterial flexibility (“hardening of arteries”)

Contributes to hypertension (abnormally high BP levels)

Question 11

Atherosclerosis

Answer 11

Disease in which lipid containing plaques build up in arteries
Plaque forms in artery when something irritates lining of artery wall
Thrombus (clot) forms
Thrombus breaks away and travels through blood (it is now an embolus)
Embolus: lodges in heart vessel, may cause heart attack (or stroke if lodges in vessel to brain)