Lipids Lecture 10-11 Flashcards Preview

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Flashcards in Lipids Lecture 10-11 Deck (46)
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1
Q

what is the importance of fats in the body?

A
energy fuel
energy stores
emergency reserve
padding
insulation
cell membrance
raw material
2
Q

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

A

80 to 90 percent

3
Q

what is the importance of fats in the food?

A
nutrients
transport
energy
sensory appeal
appetite
texture
satiety
4
Q

what type of vitamins do fats carry?

A

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

5
Q

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

A

fats

6
Q

how do fats protect the internal organs form shock?

A

by serving as a cushioning form inside the body cavity

7
Q

what forms the major material of cell membrane?

A

fats

8
Q

what is cholersterol’s role in the body?

A

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

9
Q

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

A

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

10
Q

what is LDL?

A

transports cholesterol and other lipids to tissues for use

11
Q

what is HDL?

A

transports cholesterol from body’s cells to liver for disposal

12
Q

what is VLDL?

A

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

13
Q

what is LDL made of?

A

more lipid, less protein

14
Q

what is HDL made of?

A

less lipid, more protein

15
Q

what is the difference between HDL and LDL?

A

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

16
Q

what happens when LDL cholesterol is too high?

A

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

17
Q

LDL is smaller than HDL, T/F?

A

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

18
Q

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

A

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.

19
Q

what are the three classes of lipids?

A

Triglycerides, phospholipids, and sterols

20
Q

what are triglycerides?

A

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

21
Q

what are phospholipids?

A

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)

22
Q

what are sterols?

A

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).
23
Q

How are fats digested, absorbed, and excreted?

A

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

24
Q

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

A

True

25
Q

what accomplishes most fat digestion in the small intestine?

A

digestive enzymes

26
Q

what emulsifies fat?

A

bile

27
Q

what is triglyceride cleaved into?

A

free fatty acids, glycerol, and monoglycerides

28
Q

once in the intestinal lining, what absorbs the fats?

A

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

29
Q

how are chylomicrons formed?

A

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

30
Q

the digestive tract absorbs triglycerides with remarkable efficiency?

A

yes

31
Q

how many of the fats are absorbed?

A

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

32
Q

what are the two essential polyunsaturated fatty acids?

A

linoleic acid and linolenic acid

33
Q

what is linoleic acid?

A

Omega-6 fatty acid, Arachidonic acid

34
Q

what is linolenic acid?

A

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

35
Q

what happens when you have deficient essential fatty acids?

A

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

36
Q

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

A

arachidonic acid, this is then turnt into eicosanoids

37
Q

what are eicosanoids?

A

biologically active compounds that regulate body functions

38
Q

what are omega three fatty acids?

A

● 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

39
Q

what are omega six fatty acids

A

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)

40
Q

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

A

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

41
Q

what is arachidonic acid synthesized from?

A

linoleic acid

42
Q

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

A

arachidonic acid; omega six

43
Q

what does an omega 3 eicosanoid do?

A

relaxes blood vessels and lowers blood pressure

44
Q

what does an omega 6 eicosanoid do?

A

it constricts the vessels and increases the pressure

45
Q

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

A

it promotes normal blood pressure

46
Q

what are the roles of essential fatty acids?

A

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.