Fatty Acid Oxidation

Question 1

Primary site of lipid digestion

Answer 1

Small intestines

Question 2

How Lipid Digestion, Absorption and Transport occur

Answer 2

Triglyceride made out of three fatty acids and glycerol.
Lingual lipase from glands of tongue and pancreatic lipase (Lipases are water-soluble enzymes) break off two fatty acids leaving monoglycerides.

Chyme mixed with bile inside duodenum which initiates emulsification. Chemical digestion is improved by bile salts when they emulsify lipid drops to tiny emulsion droplets increasing access for pancreatic lipases. These pancreatic lipases break triglycerides apart releasing monoglycyerides and fatty acids which react with bile salts in chyme forming micelles. These are lipid bile salt complexes.

Micelle contract intestinal epithelium and lipids diffuse across the plasma membrane to cytoplasm. New triglycerides are synthesized by monoglycerides and fatty acids. The triglycerides, fat soluble vitamins, phospholipids and steroids become coated with proteins known as chylomicrons.
Bile salt within micells are reabsorbed by sodium linked cotransport.

Chylomicrone transport dietary fats to muscle and adipose cells.
VLDL formed in the liver reaches adipose cells can gets converted to LDL by enzyme lipoprotein lipase. LDL delivered to tissues throughout. Adipose cells remove triglycerides. HDL pick up leftover lipids and transport back into liver.
Bile produced from remaining lipids and delivered back to the small intestine.

Question 3

How LDL is removed from plasma

Answer 3

Cholesterol obtained by body, use endocytosis toremove LDL from plasma

Question 4

HDL protein function and mechanism

Answer 4

HDL have high level of protein, low levels of lipids.
Removes choleterol from tissues
Send it to the liver

HDL pick up cholesterol enter liver cells via receptor mediated endocytosis.
The liver excretes the cholesterol into bile or uses it to create bile salts.
Intestine reabsorbes cholesterol and bile salts and repeat cycle.
Excess bile excreted in feces.

Question 5

How does an organism transport water insoluble substances example, lipids?

Answer 5

In the form of lipid/protein complexes such as lipoproteins

The protein wraps around a lipid droplet and thereby makes it soluble.

Question 6

Transport what to where

1. Chylomicrons
2. VLDL, IDL (intermediate density lipoprotein) and LDL
3. HDL

Answer 6

1. From intestine to through lymphatic vessel into blood/periphery
2. Made by liver to transport endogenous lipids to periphery
3. Transport Cholesterol from periphery back to the liver.

Question 7

What molecule coats lipoprotein surface

Answer 7

Apolipoproteins

Question 8

Type oxidation that occurs in organelles:

1. Mitochondria
2. Peroxisome
3. Endoplasmic reticulum

Answer 8

1. Beta-oxidation
2. Alpha-beta oxidation
3. Omega

Question 9

Role of hormone sensitive lipase

Answer 9

Releases fatty acids from intracellular triacylglycerol stores

Question 10

Role of Lipoprotein lipases

Answer 10

Release fatty acids from lipoproteins into bloodstream