The Role of Micelles in the Absorption of Lipids\

Question 1

The products of lipid digestion are

Answer 1

fatty acids, monoglycerides and glycerol

Question 2

Absorption of these products is significantly different from the absorption of carbohydrates and proteins

The monoglycerides and fatty acids associate with ………….. to form……

Answer 2

phospholipids and bile salts to form micelles (very small droplets)

Question 3

What does the formation of micelles do to help monoglycerides and fatty acids

Answer 3

Monoglycerides and fatty acids are not very soluble so the micelles aid the transport of these molecules to the surface of the epithelial cells

Question 4

The micelles break down and add to a pool of ………………. that are dissolved in the small intestine solution surrounding the …………cells.

These freely dissolved molecules enter the epithelial cell by ………….

Answer 4

fatty acids and monoglycerides

epithelia

diffusion

Question 5

pool of fatty acids and monoglycerides can can diffuse through the phospholipid bilayer of the cell membrane

why

Answer 5

They are non-polar molecules

Question 6

The short fatty acid chains within the epithelial cells can move directly into …………. via …

Answer 6

The short fatty acid chains within the epithelial cells can move directly into the blood via diffusion but the longer chains are unable to do so

Question 7

The longer fatty acid chains recombine with

to form

in the …

Answer 7

monoglycerides and glycerol to form triglycerides in the endoplasmic reticulum

Question 8

The triglycerides are packaged into lipoproteins called

Answer 8

chylomicrons

Question 9

Chylomicron structure is

Answer 9

spherical ‘case’ made of phospholipids and lipoproteins that hold the non-polar triglycerides inside, hidden from the aqueous environment of the cytoplasm and blood

Cholesterol and phospholipids are also found within chylomicrons

Question 10

These droplets are transported to a lacteal which is what

via

Answer 10

lacteal is a lymph vessel within the villus)

exocytosis- outward bulk transport of materials out of the cell surface membrane

Question 11

Eventually, chylomicrons enter the

Answer 11

bloodstream

Question 12

There are a lot of different terms used to refer to different parts of the digestive system. Remember that the ileum is the end section of the small intestine, so we can say that the absorption of amino acids occurs at the end of the small intestine.An example of a question you could get in the exam:Explain how carbohydrate and protein digestion differs from lipid digestion