Fat Flashcards
Types of lipids
Triglycerides (fats and oils) (fatty acids)
Sterols
Phospholipids
Dietary fat types
Unsaturated
- Mono (omega 9) and polyunsaturated (omega 3 and 6)
Saturated
What is trans fat
An inbetween saturated and unsaturated fats.
So, they are unsaturated fats with the H atoms in the trans configuration
What do all fat types have in common
Glycerol backbone
Saturated fatty acid: no double bond
Monounsaturated fatty acid:
1 double bond
Polyunsaturated fatty acid:
More than one double bond
What is an omega fat?
Omega-n refers to the number (n) of the carbon atoms with the first double bond from the methyl group.
So omega 3 has 3 carbons to the left of the double bond
2 essential fatty acids
omega 3 and 6
Omega 3 and 6 pathway
Lecture Slide
ARACHIDONIC ACID (AA) and DOCOSAHEXAEONIC ACID (DHA) role?
Brain development and vision
important for them to be in balance because need a balance between
states of pro-inflammatory & anti-inflammatory
Physical Properties of Saturated and Unsaturated Fats
Saturated:
Saturated fats are solid at room temperature
Saturated fat is more resistant to oxidation
Unsaturated:
* Polyunsaturated liquid at room temperature
* Monounsaturated fat is slightly less susceptible to spoilage
* Polyunsaturated fat spoils most readily
* Hydrogenation
- more likely to be oxygenated
– Protects against oxidation, therefore prolonging shelf life
– Alters texture
Examples of foods with polyunsaturated, monosaturated and saturated fats
polyunsaturated
Flaxseed oil
Walnut oil
Sunflower oil
Corn oil
Soybean oil
mono-saturated
Olive oil
Canola oil
Peanut oil
saturated fats
Coconut oil
Butter
Palm oil
Lard
Fat Digestion process
- THE MOUTH
* Mechanical digestion
* Chewing and crushing - SALIVARY GLANDS
Chemical digestion
Moisten fat rich foods mixed with salvia.
Enzyme -lingual lipase (Acid stable lingual lipase initates lipid digestion) - STOMACH
Enzyme -lingual lipase (Acid stable lingual lipase initates lipid digestion in stomach as well because its stable in high acid conditions)
- Muscle contractions - disperse fat into smaller droplets and so Fat exposed to gastric lipase - Gallbladder
- Cholecystokinin (CCK) signals the gallbladder to release bile.
Fat = Emulsified fat (through BILE) - Pancreas
1.Pancreatic Lipase (main) - Pancreatic colipase -> activated by trypsin
- Small intestine
Emulisified fat (triglycerides) = monoglycerdies, glycerol, fatty acids, cholestrol
Action of bile salts
- how do they breakdown fats
Surfactant , helps basically break down the fat by enabling the mixture of water & fat together and enzyme binding
So bile allows
Emulsification of fat droplets
Formation of mixed micelles -> enzyme + fatty acid particles
Aid absorption -> enable attachment to enterocytes so the fatty acids can be absorbed
Cycle of bile and fat
In the liver, bile is made from cholestrol
In the glallbladder the bile is stored
In the small intestine, bile emulifies fats
- either
1. Bile reabsorbed into the blood (enterohepatic recirculation
2. In the colon the bile has been trapped by coluable fibres and is lost in stool
Lecture Slide
Label cells of small intestine and process of absorption of glycerol and small lipids VS large lipids
Lecture Slide
How does fat get across membrane
Micelle
formed by fatty acids & bile , helps take fatty acids to enterocytes to get them across membrane (micelle itself doesn’t go across) but transport proteins take fatty acids into the enterocytes
In the enterocytes, they are repackaged with protein, cholestrol and fat soluable vitamins and made into chylomicron. They enter the lymphatics
Chylomicrions travel into the lacteals of the lymh gland in the villi and go via lymph to the blood
Endogenous (LDL) vs reverse transport pathway (HDL) vs exogenous pathway
Lecture Slide
