digestion and absorption

Question 1

Describe the processes involved in the absorption and transport of
digested lipid molecules from the ileum into lymph vessels.

Answer 1

1. Micelles contain bile salts and fatty acids/monoglycerides;
   2.Make fatty acids/monoglycerides (more) soluble (in water),
   3.Fatty acids/monoglycerides absorbed by simple diffusion;
   4.chylomicrons formed
2. chylomicrons packages in vesicles which move towards the cell membrane for exocytosis.

Question 2

why are lipids not soluble?

Answer 2

non polar

Question 3

what do micelles do for lipids?

Answer 3

-make fatty acids more soluble in water
-carrying the fact acids to the epithelial cells
- help maintaining a concentration gradient of fatty acids diffusing into the epithelial cells. (micelles have more fatty acids which are outside of the epithelial cell)

Question 4

how come facts acids can move in via simple diffuse across the epithelial cells?

Answer 4

fatty acids are non polar so can diffuse across phospholipid membrane

Question 5

what happens when chylomicrons are formed in the Golgi apparatus?

Answer 5

chylomicrons are put into vesicles which move towards cell membrane and leave via exocytosis

Question 6

how is the Golgi apparatus or endopalmsic reticulum important in lipid digestion ?

Answer 6

modify triglycerides
combining them with proteins to form chylomicrons
chymolmicrons are packaged into vesicles

Question 7

The movement of Na+ out of the cell allows the absorption of glucose into
the cell lining the ileum.
Explain how.

Answer 7

MAINTAINS/ GENERATES a concentration gradient from sodium ions so sodium ions move into epithelial cell
Sodium moves in epithelia cell vai facilitated diffusions with glucose.

Question 8

how will the concentration of fatty acids and triglycerides be affected by time.

Answer 8

-Triglycerides decrease because they are are hydrolysed into fatty acids by lipase
-Ester bonds are hydrolysed so less triglycerides
-fatty acids increase because of the hydrolysis of triglycerides

Question 9

Describe the role of micelles in the absorption of fats into the cells lining
the ileum.

Answer 9

1. Micelles include bile salts and fatty acids;
   2.Make the fatty acids (more) soluble in water;
   3.5. Fatty acids (absorbed) by diffusion;

Question 10

Describe the role of enzymes in the digestion of proteins in a mammal.

Answer 10

1. (Reference to) enzymes hydrolyse the peptide bonds;
2. endopeptideases hydrolyse peptide bonds in the middle of poly peptide
3. exopeptidase hydrolyse peptide bonds at the end of polypeptide forming dipetide
   4.dipeptidases hydrolyse petide bond of dipeptide into amino acids

Question 11

if there are is overlap of standard deviations what does this mean about graph?

Answer 11

• not statistically significant
  -standard deviation over lap
• SO.. this means that x and y have no effect on each other
  MUST RELATE BACK TO QUESTIOSN

Question 12

How is the Golgi apparats involved?

Answer 12

1. Golgi (apparatus);
2. Modifies / processes triglycerides;
3. Combines triglycerides with proteins to form chylomicrons ;
4. Packaged for release / exocytosis