DIGESTION OF LIPIDS Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Why are some enzymes membrane bound

A

Being fixed to the membrane of the gut epithelium is more efficient since the enzyme is not removed and can be reused
Even when the epithelial cell is rubbed odd, the enzyme can still function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is lipid digestion hydrolysed by

A

Lipases produced in the pancreas and absorbed in the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the problem with lipid digestion

A

Lipids are insoluble
Enzymes are soluble
Enzyme action only on the surface of each droplet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Bile production

A

Produced in the liver and stored in the gall bladdee nefore being injected into the duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe emulsification

A

A process in which large lipid globules are broken down into several small lipid globules
These small globules are widely distributed in the chyme rather than forming large aggregates
Lipids are hydrophobic
Bile contains bile salts which have hydrophobic and hydrophilic sides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Role of bile

A

Lipids are first split into tiny droplets called micelles by bile salts which emulsify fats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Benefit of emulsification

A

Smaller droplets increases surface area of lipids so a faster rate of reaction for lipases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are micelles

A

Micelles allow both fatty acids and monoglycerides to pass through the epithelial membrane
Complicated process which is summarised as diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the digestion of lipids

A

Bile salts emulsify the lipid to form smaller droplets called micelles
Micelles carry fatty acids and monoglycerides to membrane via diffusion
Golgi apparatus modifies and processes triglycerides
Triglycerides associated with cholestrol and proteins
Packaged for release exocytosis as chylomicrons
Lacteal (lymphatic system) takes the chylomicrons to the blood system
Chylomicrons hydrolysed by an enzyme in the endothelial cells of capillaries and then diffuse into cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Lipid digestion

A
  1. Emulsification of lipids into smaller droplets increases sa of lipids and lipases break it down faster
  2. Lipases hydrolyse ester bonds in triglycerides forming fatty acids and monoglycerides
  3. Formation of micelles
  4. Micelles transport the fatty acids and monoglycerides to epithelial cells
  5. Fatty acids and monoglycerides cross the cell surface membrane by diffusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Lipid absorption

A

Inside the epithelial cell
1. Fatty acids and monoglycerides form triglycerides at the endoplasmic reticulum
2. The triglyceride then combine with lipoproteins and cholestrol in the golgi body, forming chylomicrons
3. Vesicles pinching off the end of the golgi body containign chylomicrons, travel to the bottom surface of the epithelial cell and fuse to it
4. This releases the chylomicrons out of the cell (exocytosis)
5. Chylomicrons enter the lacteal (lymph vessel) where they are carried to the blood system
6. Chylomicrons and triglycerides are hydrolysed by enzymes in the endothelial cells of blood capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly