Dietary Lipids Flashcards
Basic functions of lipids
Energy
Storage
Membranes
Aid indigestion and metabolism
Precursor for hormones and vitamins
Component of cell membranes
Protects our nerves and internal organs as a thermal covering
Essential for growth
Short chain FA size(# of carbons)
2-4
Medium chain fatty acid size (# of carbons)
5-12
Long chain fatty acid size (# of carbons)
13-21
Very long chain fatty acids (# of chains)
More than 22
Are SCFA soluble in water?
Yes
Are MCFA soluble
Fairly
Are LCFA soluble
Insoluble
Are VLCFA soluble
Insoluble
Source of SCFA
Bovine milk
Swiss cheese
Plants silage
Produced by the colonic bacteria in human gut
Source of MCFA
Coconut oil
Plam kernel oils
Butterfat
Source of LCFA
Animal fats
Vegetable oils
Marine oils
VLCFA source
Plant oils
Peanut oils
Most common FA are
16 and 18 carbons
Most FA are _____ and have ____ confirmation
Unsaturated
Cis
Most FA are
Long
What are the essential FA what omega are they
Linoleic acid ω6
Linolenic acid ω3
Source of linoleic acid omega 6
Egg, meats, grains, nuts, most plant seeds and oils
Linolenic acid source omega 3
Fish, seeds, plant oils, green leafy veggies
Which FA is anti inflammatory
Ω3
Which FA is inflammatory
Ω6
Archidonic acid is the main culprit of
Pro inflammatory products
_____ can inhibit the formation of arachidonic acid
Eicosapentanonic
Steps to make an ω6 FA
Linoleic acid to gamma linolenic acid to arachidonic acid
Steps to make an ω3 FA
Alpha-linolenic acid to eicosapentanonic acid to docosahexaenoic acid
Non polar lipids ______ are usually in our diet our how we store our fat
Triglycerides
Where can polar lipids be found
In the membranes of our cell
Phospholipid structure composition
1 glycerol backbone
3 fatty acids
Glycerolipidphospholipid structural composition
Glycerol backbone
Phosphate
Head group (alcohol)
2 fatty acids
Sphingolipid structural composition
Sphinogine back bone
1 fatty acid
And either
Phosphate and a head group
Or
Carbohydrate
All cells can synthesize ___
Cholesterol
Cholesterol comes from
Acetyl CoA
What can cholesterol make
Bile salts
Steroid hormone
Membranes
Blood lipoprotein
Cholesterols are usually polar or non polar
Polar form
Where are bile salts made and by what
Liver peroxisome
By cytochrome P450 mediated oxidation
How do bile salts work
Like a detergent
On one side is all the hydrophobic molecules and on the other is all the hydrophilic
The hydrophobic sides surround the big lipid molecule, the hydrophilic side is in contact with the aqueous solution of your body
Bile stored in ____ and released when there is ____ in our stomach
Liver
Fat
Bile acids make ___
Micelles
Why do you want to break down bile salts to micelles
Cuz they can diffuse (freely) through epithelial cells and for the CHYLOMICRON
Most of our dietary fat is made up of
Triglycerides
Importance of bile acid
Emulsify fat for digestion
Michelle formation, which makes products of lipid digestion soluble
Absorption of fat-soluble vitamins
Keeps cholesterol soluble in the gallbladder
Preventing gallstone formation
Helps in intestinal motility allowing defecation
Steps to make bile acid
- Cholesterol to cholic acid (with cholesterol 7α hydroxylase)
- Cholic acid gets conjugated to glycocholic acid or taurocholic acid ( these dudes have a low PK which means they’re more reactive and more soluble)
3.the conjugated forms become the bile salts
Cholesterol 7 α hydroxylase is a ____ enzyme
Rate limiting
The amount of bile acid made equals
The amount of bile acid excreted
Basic absorption of FA
FA to triglycerides
Packaged to chylomicrons in intestinal cells
To lymph
To bloodstream
Basic absorption of cholesterol
Cholesterol esters formed in enterocytes
Enzyme ACAT
function to turn cholesterol and FA to cholesteryl esters
The c. Esters go to lymph
And then to the blood stream
Majority of bile salts are recycled as primary or secondary conjugated bile salts by _______
Active transport from proximal or distal ileum
Additional bile is recycled by _____
Passive diffusion
Statin inhibits
Cholesterol from being made
Ezetimibe inhibits
The uptake of cholesterol from the small intestine into the blood
Resins inhibit
Bile from getting back into liver
What is the response to bile acid chelators
Give an example of one
Inhibits bile from being re-absorbed. SO more cholesterol is converted to bile acids
What are the pancreatic enzymes and what do they digest
Pancreatic lipase with colipase = digests triacylglycerols
Phospholipase = digest phospholipids
Cholesterol esterase = digest cholesterol esters
Where do the pancreatic enzymes secrete and what do
Into the small intestine
Digest LCFA
What are the enzymes in the mouth and what do they digest
Lingual lipase
It digest SCFA and MCFA
Enzyme in stomach and what does it do
Gastric lipase
Digest SCFA and MCFA
Where does most of the digestion of SCFA and MCFA happen
Stomach
Here do SCFA and MCFA go after being digested in stomach
Diffuse (cuz they’re so smol) and enter blood
When SCFA and MCFA enter blood after being digested in stomach where do they go
To the hepatic portal blood, then carried by serum albumin to the liver
During fasting states what fat do we rely on
LCFA
Triglycerides are made in the
Liver
LCFA play a big role in
Development of immunity and brain development
Why do we need co lipase
Because the fat droplet inhibits lipase
Explain process of lipase on fat droplet
1 Co lipase binds
2 lipase binds to co lipase
3 lipase takes fat insides and breaks them up and spits them out ast micelles
Phospholipase A1 and A2 create
Free FA
SCFA are formed in the ______ by friendly bacteria and are rapidly metabolized by the _____
Intestines
Intestinal cells
MCFA are absorbed and transported _______ to the liver where they are ______
Liver
Burned for energy
LCFA are turned into _____ and then are taken up by cells and used for _____ or _____
Triglycerides
Energy
Stored
_____ is needed from ____ to digest LCFA
Bile
Gallbladder
CHYLOMICRON carries
Dietary fats
Chylomicrons go to where
Lympatic system, not capillaries
Chylomicrons deliver fat to
Muscle for energy
Or
Fat for storage
What regulates LPL
Insulin
High insulin regulates
LPL sythesis and activity
It will all increase
KM for muscle LPL compared to fat LPL
Muscle has a lower KM
this means muscle LPL is always saturated
FED state what does LPL sythesis and activity look like in adipocytes
High
FED state what does LPL sythesis and activity look like in skeletal muscles and heart
Low
Fasting state what does LPL sythesis and activity look like in adipocytes
Low
Fasting state what does LPL sythesis and activity look like in skeletal and heart muscle
High
What does secretin activate
Secretion of bicarbonate from pancrease
What does cholecystokinin do
1 inhibits gastric motility
2 triggers pancreatic enzymes from pancreas
3 triggers bile release from gall bladder
Steatorrhea
Fatty poop
What can cause steatorrhea
Celiac disease
Chron’s
Cystic fibrosis
Why
1 liver problems
2 blocked bile duct
3 blocked pancreatic duct
4 defective absorptive cells
MALABSORPTION OF LIPIDS
If you have issues absorbing fat you’ll also have issues absorbing
Fat soluble vitamins
Where are chylomicrons made
In enterocyte golgi/SER
Who organizes the assembly of chylomicrons
Apo B
What do you need to make chylomicrons
Phospholipids
Where to chylomicrons pick up apo A, C, E
In plasma
Chylomicrons are mainly made of
Triglycerides
Who makes sure chylomicrons are mature and how does it do that
HDL
HDL donates APO C-II and APO E
CHYLOMICRON without the assistance of HDL is called _____ it is newly _____
Nascent
Released
Maturation of chylomicrons happens in
Blood
Bile salts are responsible for the ___ of smaller droplets
Stabilization
Why do bile salts accelerate the action of pancreatic lipase
Because, it can bind colipase. Once colipase is bound it can bind lipase, which breaks down the fat
What do micelles transport
2-monoglycerides and FA
