Ch 5: Lipids Flashcards

(55 cards)

1
Q

chem structure of fatty acids

A

organic acid
C chains w H attached
- carboxylic acid group
- methyl group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

fatty acid chain length

A
even # of C
18-C is most abundant found in food
Long 12-24 C
Medium 6-10 C
Short less than 6 C
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

degree of unsaturation of fatty acids

A

amt of double bonds present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

unsaturated fatty acids

A

monounsaturated- 1 double bond (point of unsaturation)

polyunsaturated- 2+ double bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

saturated fatty acids

A

no double bonds b/w carbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

naming polyunsaturated fatty acids

A
  • from first unit of unsaturation from methyl end

- omega number for monounsaturated FAs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

triglycerides chemical structure

A

glycerol backbone w 3 fatty acids

- very few fatty acids are free in the body, most are part of triglycerides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how are triglycerides formed?

A

condensation reactions

- produce water from H and hydroxyl (OH-)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

factors contributing to functional properties of triglycerides

A

chain length
degree of saturation
position of double bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

properties of saturated triglycerides ex

A

the more saturated TG, the more solid at room temp it is

ex. animal fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

coconut and palm oil structures

A

firmer than most veg oils but still softer than animals fats
- bc of shorter chain length
8-14C
palm oil almost 50/50 saturated to polyunsaturated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

shorter chain length = ?

A

softer at room temp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

saturation of triglycerides provides __?

A

stability
unsaturated fatty acids oxidize more easily, causes spoiling
– manufactures place their products in air tight containers, add antioxidants, or hydrogenate their products to prevent spoiling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

hydrogenation

A

H atoms added to unsaturated fatty acids

  • makes liquid fat more solid at room temp.
  • increases the shelf life of food
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Trans - fatty acids

A

from partially hydrogenated, rather than completely hydrogenated fatty acids

  • behave like saturated fats in the body
    • cis bonds are not as negative healthwise as trans fatty acids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Phospholipids

plus ex.

A

act as emulsifier
- fatty acid portion makes fat soluble
- phosphate portion makes water soluble
ex. our cell membranes, allows water & fat soluble vit & hormones to pass through
ex 2. lipoproteins in our blood, transport fats through bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

emulsifier

A
  • a substance w both water-soluble and fat-soluble portions

- promotes the mixing of oils and fats in watery solutions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Lecithin

A

supplementation is problematic bc our liver makes all the lecithin that we need, therefore it is not an essential nutrient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

micelle

A

emulsified fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

sterols

A

have multi ring structure

ex. cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

cholesterol

A
  • from animal prod. only
  • made by liver, 800-1500mg/day
  • used to make bile acids, sex and adrenal hormones, vitD
  • procides structural support for our cell membranes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

plant sterols

A

shown to decrease cholesterol levels and inhibit cholesterol absorption
- thus has been added to food such as margarine in an effort to decrease blood cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

emulsification of fat

A

occurs in sm intestine

bile emulsifies fat, breaks down into fat droplets (micelles) that repel one another

24
Q

enterophatic circulation

A

bile in GI tract has 2 possible fates:

  • reabsorbed by sm intestine and sent back to liver to be recycled
  • excreted (absorbed by soluble fibres) , may lower cholesterol levels
25
lipid digestion in the mouth
- body temp causes fat to become more fluid | - salivary glands produce lingual lipase that hydrolyzes fats
26
lipid digestion in the stomach
constant churning muscular action of stomach causes fats to be dispersed into smaller fat droplets to be exposed to gastric lipase
27
lipid digestion in small intestine
- when fat enters, it stimulates the release of cholecystokinin (CCK) which causes the gallbladder to release bile - bile acids pair up w amino acids to emulsify fat - - amino end attracts water and sterol end attracts fat, this draws fat into lumen (water-based) and allows pancreatic and intestinal lipases to further digest fat droplets
28
end products of lipid digestion
- monoglycerides - some fatty acids - very little glycerol
29
triglyceride digestion
- pancreatic and intestinal lipases hydrolyze each fatty acid on the TG gives 2 free fatty acids and a monoglyceride
30
phospholipid digestion
2 fatty acids and a phospholipid component are absorbed
31
sterol digestion
- absorbed as is | EXCEPT when fatty acid is attached then is need to be hydrolyzed first and both components can be absorbed
32
lipid transport
``` by way of lipoproteins, 4 types: chylomicrons Very Low Density Lipoprotein Low Density Lipoprotein High Density Lipoprotein ```
33
Absorption of lipids
the larger the molecule, the harder it is to absorb - monoglycerides and long chain fatty acids are broken down by bile into micelles to be able to diffuse easily across cell membrane
34
lipoproetin lipase
- enzyme activated in response to insulin - hydrolyzes triglycerides, allowing components to move into cell - located on an endothelial cell lining capillaries around adipose, muscle and heart
35
chylomicrons
- largest, least dense - transport diet-derived lipids to the body for immediate use - as tissues (muscle, adipose) remove triglycerides, chylomicron becomes known as chylomicron remnant (now smaller and more dense) - liver collects remnants, breaks down and recycles
36
VLDL
- made from chylomicron remnants - travel in blood to tissues where they lose TG (deliver to body tissues) - as lipids are removed from VLDL, it becomes dense and full of cholesterol, smaller = LDL
37
LDL
transport cholesterol to body cells or returns to liver to be removed from circulation - (bad) cholesterol
38
HDL
- smallest, most dense - formed by liver cells, pick up cholesterol from the body cells and brings it back to the liver for excretion - anti-inflammatory properties - (good) cholesterol
39
inflammation
fat that has oxidized, | oxidized fat sticks better to artery walls
40
factors that lower LDL/raise HDL
- weight control - mono- or polyunsaturated fats in diet rather than saturated - soluble dietary fibres - phytochemicals - moderate alcohol consumption - physical activity - medication can lower LDL but does not increase HDL
41
health effects of lipids hint: think cholesterol
heart disease - major risk factor is elevated blood cholesterol - - this is bc it accumulates in arteries, restricts bloodflow and can lead to heart attack or stroke - over 40% of canadians ages 20-75 have unhealthy blood cholesterol levels
42
the process of atherosclerosis
see notes this is quite a lot
43
RDA and UL for fat
no RDA or UL for fat | - the general public does not know the difference bw good and bad fats, risks restricting good fats
44
role of triglycerides in the body
provide energy (9kcal/g) unlimited storage form of energy Adipose tissue: - stores fat, serve as insulation, shock absorption, cell membrane structures, secrets hormones adipokines: regulate energy balance, feelings of satiety
45
essential fatty acids in the body
linoleic acid - omega 6 linolenic acid - omega 3 eicosanoids - made from n-6 and n-3
46
linoleic acid
omega 6 component of membrane phospholipids make arachidonic acid
47
linolenic acid
omega 3 component of membrane phospholipids make EPA and DHA
48
eicosanoids
- made from n-6 and n-3 - hormone like inflammatory mediating compounds - if made w n-6 are inflammatory, n-3 are anti-inflammatory
49
olive oil
positive impacts on vascular system, healthy arteries - in countries where olive oil consumption in increased they have lower BP, lower rates of heart disease, lower LDL oxidation, etc
50
nuts
- energy dense, high in fat, healthy fat - mono and polyunsaturated fats - fibre, protein and more stuff - contain plant sterols - phytochemicals that act as antioxidants
51
the Mediterranean diet
lowers risk of developing chronic diseases - high in fat but lower in saturated and trans fats - rich in monounsaturated fat - rich in complex CHO and fibre - nutrients and phytochemicals from fresh fruits, veg
52
fish
contain EPA and DHA (long chain fats) that benefit heart - reduce blood TG - prevent blood clots - decrease BP - defend against inflammation
53
our high omega 6/ omega 3 ratio
not good, bc they compete for the same biosynthetic enzymes and we consume a lot more omega 6 - high consumption of omega 6 (meats) leads to obesity - should increase omega 3 consumption (oils like flax, chia) and oils high in monounsaturated fats (olive, sunflower)
54
insulin
released from beta cells of pancreas | - causes glucose from the blood and moves it into cells or skeletal muscle
55
glucagon
released when the glucose is gone released from the alpha cells of the pancreas - causes glucose to be released from cells of the liver into the blood