Lipids Lecture 10-11

Question 1

what is the importance of fats in the body?

Answer 1

energy fuel
energy stores
emergency reserve
padding
insulation
cell membrance
raw material

Question 2

fats provide what percentage of the resting body’s energy and energy used to fuel muscular work

Answer 2

80 to 90 percent

Question 3

what is the importance of fats in the food?

Answer 3

nutrients
transport
energy
sensory appeal
appetite
texture
satiety

Question 4

what type of vitamins do fats carry?

Answer 4

fat soluble vitamins A,D,E, K along with phytochemicals and assist in their absorption

Question 5

what is the body’s chief form of stored energy?

Answer 5

fats

Question 6

how do fats protect the internal organs form shock?

Answer 6

by serving as a cushioning form inside the body cavity

Question 7

what forms the major material of cell membrane?

Answer 7

fats

Question 8

what is cholersterol’s role in the body?

Answer 8

it is the raw material for emulsifiers in bile for the digestion of fat.

Question 9

what is the relationship between fats and cholesterol in the body?

Answer 9

fat is emulsified by bile in the small intestine

bile shuttles lipids across mucus layer of the digestive tract to the surface of cells

lipids are used to form lipoproteins, like HDL, LDL, VLDL

Question 10

what is LDL?

Answer 10

transports cholesterol and other lipids to tissues for use

Question 11

what is HDL?

Answer 11

transports cholesterol from body’s cells to liver for disposal

Question 12

what is VLDL?

Answer 12

transports triglycerides and other lipids made in the liver to the bodys cells for their use

Question 13

what is LDL made of?

Answer 13

more lipid, less protein

Question 14

what is HDL made of?

Answer 14

less lipid, more protein

Question 15

what is the difference between HDL and LDL?

Answer 15

LDL delivers cholesterol to the tissues; HDL scavenges excess cholesterol and other lipids from the tissues, transports them via the blood stream and deposits them in the liver for disposal

Question 16

what happens when LDL cholesterol is too high?

Answer 16

it contributes to lipid buildup in tissues, like the linings of the arteries triggering inflammation and leading to heart disease.

Question 17

LDL is smaller than HDL, T/F?

Answer 17

F, LDL is larger, lighter, and richer in cholesterol; HDL is smaller denser and packaged with more protein

Question 18

how and when is fat used as fuel for the body?

Answer 18

Fat cells respond to the call for energy by dismantling stored fat molecules (triglycerides) and releasing fatty acids into the blood. Upon receiving these fatty acids, the energy-hungry cells break them down further into small fragments. Finally, each fat fragment is combined with a fragment derived from glucose, and the energy-releasing process continues, liberating energy, carbon dioxide, and water. The way to use more of the energy stored as body fat, then, is to create a greater demand for it in the tissues by decreasing the intake of food energy, by increasing the body’s expenditure of energy, or both.

Question 19

what are the three classes of lipids?

Answer 19

Triglycerides, phospholipids, and sterols

Question 20

what are triglycerides?

Answer 20

the chief form of fat in the diet and the major storage form of fat in the body, composed of a molecule of glycerol with three fatty acids attached

Question 21

what are phospholipids?

Answer 21

glycerol, two fatty acids and a phosphorus molecule
○ Soluble in water and fat
○ Emulsifier (substance that mixes with both fat and H2O and permanently disperses the fat in the water, forming an emulsion
○ Structural and regulatory roles in the cells (phospholipid bilayer)

Question 22

what are sterols?

Answer 22

ring of carbon, cholesterol roles in the body, plant sterols

• Cholesterol: cell membrane structure, not an essential nutrient.
• Other sterols include vitamin D( made from cholesterol) and steroid hormones (sex hormones).
• Plant sterols in foods inhibit cholesterol absorption (found in nuts, seeds, legumes,fruits and vegetables).

Question 23

How are fats digested, absorbed, and excreted?

Answer 23

in the mouth and stomach: little fat digestion takes place

in the small intestine: digestive enzymes accomplish most fat digestion in the small intestine. There, bile emulsifies fat, making it available for enzyme action. The enzymes cleave triglycerides into free fatty acids, glycerols, and monoglycerides

at the intestinal lining:
the parts are absorbed by intestinal villi. Glycerol and short chain fatty acids enter directly into the bloodstream

the cells of the intestinal lining convert large lipid fragments, such as monoglycerides and long chain fatty acids, back into triglycerides and combine them with protein, forming chylomicrons (a type of lipoprotein) that travels in the lymph vessels to the bloodstream

in the large intestine:
a small amount of cholesterol trapped in fiber exits with the fiber

Question 24

little fat digestion happens in the mouth and stomach, T/F?

Answer 24

True

Question 25

what accomplishes most fat digestion in the small intestine?

Answer 25

digestive enzymes

Question 26

what emulsifies fat?

Answer 26

bile

Question 27

what is triglyceride cleaved into?

Answer 27

free fatty acids, glycerol, and monoglycerides

Question 28

once in the intestinal lining, what absorbs the fats?

Answer 28

intestinal villi, so that glycerol and short chain fatty acids enter directly into the bloodstream

Question 29

how are chylomicrons formed?

Answer 29

the cells of the intestinal lining convert large lipid fragments, such as monoglycerides and long chain fatty acids, back into triglycerides and combine them with protein

Question 30

the digestive tract absorbs triglycerides with remarkable efficiency?

Answer 30

yes

Question 31

how many of the fats are absorbed?

Answer 31

98%, very little fat is excreted by a healthy system

Question 32

what are the two essential polyunsaturated fatty acids?

Answer 32

linoleic acid and linolenic acid

Question 33

what is linoleic acid?

Answer 33

Omega-6 fatty acid, Arachidonic acid

Question 34

what is linolenic acid?

Answer 34

Omega-3 family (DHA and EPA) Heart disease, cancer prevention, cell membranes, brain function and vision

Question 35

what happens when you have deficient essential fatty acids?

Answer 35

produces skin abnormalities and poor wound healing. In infants, growth is retarded and vision is impaired.

Question 36

what is an omega 6 fatty acid derived from linoleic acid?

Answer 36

arachidonic acid, this is then turnt into eicosanoids

Question 37

what are eicosanoids?

Answer 37

biologically active compounds that regulate body functions

Question 38

what are omega three fatty acids?

Answer 38

● Omega-3 fatty acids are found in the eyes and brain and are essential for normal growth, visual acuity, and cognitive development. Can also play an important role in the prevention and treatment of heart disease

Question 39

what are omega six fatty acids

Answer 39

have conditionally essential nutrients (a nutrient that is normally nonessential but must be supplied by the diet in special circumstances when the need for it exceeds the body’s ability to produce it)

Question 40

what are the benefits of omega 3 fatty acids? examples?

Answer 40

heart health, cancer prevention, cell membranes, brain function and vision; EPA and DHA, both synthesized from linolenic acid

Question 41

what is arachidonic acid synthesized from?

Answer 41

linoleic acid

Question 42

whats is a derivative of linoleic acid? is this omega 3 or omega 6 fatty acid?

Answer 42

arachidonic acid; omega six

Question 43

what does an omega 3 eicosanoid do?

Answer 43

relaxes blood vessels and lowers blood pressure

Question 44

what does an omega 6 eicosanoid do?

Answer 44

it constricts the vessels and increases the pressure

Question 45

what happens when balance is achieved between EPA and arachidonic acid?

Answer 45

it promotes normal blood pressure

Question 46

what are the roles of essential fatty acids?

Answer 46

a. ) Provide raw material for eicosanoids (signaling molecules) b. ) Serve as structural and functional parts of cell membranes. c. ) Contribute lipids to the brain and nerves. d. ) Promote normal growth and vision e. ) Maintain outer structures of the skin, thus protecting against water loss. f. ) Help regulate genetic activities affecting metabolism g. ) Participate in immune cell functions.