Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
45 Cards in this Set
- Front
- Back
|
Lipids
|
compounds that include triglycerides (fats and oils), phospholipids, and sterols
|
|
|
Fats
|
lipids that are solid at room temperature
|
|
|
oils
|
lipids that are liquid at room temperature
|
|
|
Why is fat put in food?
|
- flavor
- aroma - influences texture - supplies vitamins ADE and K |
|
|
Soft fat
|
shorter chains
more unsaturated melts more readily |
|
|
Polyunsaturated
|
less stable
can turn rancid susceptible to microbial growth |
|
|
Preventing rancidity
|
seal air-tight and refrigerate
add antioxidants add hydrogen |
|
|
Hard Fat
|
more saturated
more stable more resistant to oxidation |
|
|
Role of fat in the Body
|
Insulates body from temperature extremes
Cushions vital organs Phospholipids and sterols maintain structure & health of cells -Provides energy Nourishes scalp, hair & complexion |
|
|
How does fat supply energy?
|
almost unlimited supply
stored in adipose tissue fat cells enlarge and supply 60% of body’s ongoing energy at rest |
|
|
What are simple lipids?
|
fatty acids esterified with alcohols)
- fats - waxes |
|
|
Fats chemical make up?
|
fats (fatty acids esterified with glycerol)
|
|
|
Waxes chem makeup?
|
waxes (sterol esters, vitamin A and D esters)
|
|
|
What are complex lipids. and examples?
|
(fatty acids esterified with alcohols plus other groups)
phospholipids glycolipids lipoproteins |
|
|
Triglycerides. Made up up what? how are they formed?
|
glycerol backbone
three fatty acids formed via series of condensation reactions usually contain mixture of fatty acids |
|
|
What are fatty acids made of?
|
organic acid
methyl group at one end; acid group at other end usually even number of carbons |
|
|
which fatty acid is abundant in food?
|
18-carbon fatty acids abundant in food
|
|
|
Saturated vs. Unsaturated
|
saturated – full of hydrogens
unsaturated – missing hydrogens |
|
|
Which of the following foods provides essential fatly acids?
a0 fish only b) beef only c) plants only d) fish, beef , plants |
d)
|
|
|
Which length of fatty are usual abundant in food?
|
18- carbon
|
|
|
What are the advantages of hydrogenation?
|
- protects against oxidation
- alters texture of food |
|
|
What are the configuration possibilities of trans-fatty acids?
|
cis and trans
|
|
|
What is the structure of a phospholipids? example?
|
backbone of glycerol
2 fatty acids a phosphate group & a molecule of choline or similar compound - lecithins |
|
|
What is the role of phospholipids ?
|
are emulsifiers
are important constituents of cell membranes are not essential, made by the liver supplements are ineffective - soluble in water and fat |
|
|
what are Sterols? roles? what is made of them?
|
body compounds made from cholesterol
bile vitamin D |
|
|
what are the food sources of sterols?
|
plant sterols
cholesterol |
|
|
How does fat digestion happen? what is the goal?
|
Fats are hydrophobic
digestive enzymes are hydrophilic Goal of fat digestion dismantle triglycerides monoglycerides, fatty acids, and glycerol |
|
|
How are lipids digested in the the small intestine?
|
Cholecystokinin (CCK)
gall bladder releases bile bile acts as emulsifier Pancreatic lipase Hydrolysis triglycerides and phospholipids |
|
|
How do bile route effect lipid digestion?
|
Blood cholesterol levels
|
|
|
explain the emulsification of fat by bile?
|
explain the emulsification of fat by bile?
|
|
|
Describe the entrohepatic circulation of bile:
|
in liver: bile made from cholesterol
In the gall bladder: bile is stored SI: biles emulsifies fat and is then either returned to liver though blood reabsorption or in colon: bile trapped by soluble fibres and excreted in feces |
|
|
What lipids are absorbed directly into the bloodstream:
|
glycerol and short- and medium-chain fatty acids
|
|
|
How is lipid absorbed into lymphatic system?
|
micelles diffuse into intestinal cells
reassembly of triglycerides packed with proteins – chylomicrons bypass liver at first |
|
|
What are the four main types of lipoproteins?
|
Chylomicrons
Very-low-density lipoproteins (VLDL) Low-density lipoproteins (LDL) High-density lipoproteins (HDL) |
|
|
Chylomicrons:
|
largest and least dense
transport diet derived lipids liver removes remnants from blood |
|
|
Very low density lipoproteins
|
made in liver
proportion of lipid shift |
|
|
low density lipoproteins
|
cell needs
liver regulation |
|
|
high density lipoproteins
|
remove cholesterol from cells
carry cholesterol to liver for recycling anit- inflammatory properties |
|
|
what is the role of triglycerides?
|
provide energy to cells:
(9 calories per gram) - unlimited ability to store fat energy in body Adipose tissue: - secrets hormones (adipokines) Skin insulation shock absorption cell membrane cell signalling pathways |
|
|
What are the essential fatty acids?
|
Linoleic acid (Omega-6 fatty acid)
Linolenic acid (Omega-3 fatty acid) Fatty acid deficiencies |
|
|
Linolenic acid (Omega-3 fatty acid) include?
|
DHA (docosahexaenoic acid)(22:6)
EPA (eicosapentaenoic acid)(20:5) eicosanoids |
|
|
How do adipose cells store fat after meals?
|
lipoprotien lipase: hydrolyzes triglycerides
- then triglycerides are reassembled inside adipose cells |
|
|
What is a main culprit in heart disease?
|
elevated blood cholesterol
|
|
|
How is blood cholesterol elevated?
|
saturated fats- increase the LDL cholesterol which promotes blood clotting
- dietary choises - trans fat - increase LDL - dietary cholesterol |
|
|
What the total daily recommended intake of fat? saturated fat? cholesterol, omega 6? omega 3
|
20-35%
- saturated= 10% - less than 300 mg - 5-10 - 0.6-1.2 |
