Lecture 26 and 27

Question 1

Products of fat digestion are
A. Delivered to the brush border via micelles
B. Absorbed via active transport
C. Absorbed via an osmotic gradient set up by the absorption of salts and nutrients
D. Broken down from triglycerides into monosaccharides

Answer 1

A

Question 2

CCK
A. Stimulates enzyme secretion by acinar cells
B. Stimulates HCO2 secretion by duct cells
C. Is produced by duodenal endocrine cells in response to increase H+
D. Neutralizes acidic chyme

Answer 2

A.

Question 3

What are the main nutrients that undergo chemical digestion?

Answer 3

• Carbs
• Proteins
• Lipids

Question 4

Long chains of glucose are joined by?

Answer 4

Alpha 1-4 glycosisdic bonds

Question 5

Long chains of amino acids are linked together by?

Answer 5

Peptide bonds

Question 6

Salivary enzymes are: 
A. Acidic 
B. Alkaline 
C. Basic 
D. poisonous

Answer 6

Both B and C

Question 7

Gastric enzymes are :
A. Acidic
B. Alkaline
C. Poisonous

Answer 7

B.

Question 8

Cellulose are structural polysaccharides that are linked together by long chains of?

Answer 8

Beta 1-4 glycosidic bonds

Question 9

In luminal digestion, polysaccharides are:
A. Converted to oligosaccharides and disaccharides
B. Converted to Monosaccharides
C. Not changed

Answer 9

A

Question 10

In contact digestion, disaccharides are converted to?

Answer 10

Monosaccharides

Question 11

Which enzymes are involved n contact digestion?

Answer 11

Sucrase, lactase and maltase

Question 12

In luminal digestion, proteins are converted into?

Answer 12

Polypeptides

Question 13

In contact digestion, polypeptides are converted into

Answer 13

Individual amino acids

Question 14

Where are lipids digested?

Answer 14

In the lumen of the small intestine. NO contact digestion.

Question 15

What is the main enzyme involved in the digestion of lipids?

Answer 15

Pancreatic lipase

Question 16

Which enzymes have a minor role in the digestion of lipids?

Answer 16

Lingual lipase and gastric lipase

Question 17

What is the problem with the digestion of lipids

Answer 17

Lipids are insoluble in water so it requires a more complex process

Question 18

Chemical digestion order…

Answer 18

Emulsification, stabilisation, Digestion and formation of micelles

Question 19

What is emulsification?

Answer 19

Motility breaks up lipid droplets into small droplets. This will increase surface area for digestion.

Question 20

Where does emulsification occur?

Answer 20

In the stomach by retropulsion and in the small intestine by segmentation (the bile salts stabilize droplets)

Question 21

Where does stabilization occur?

Answer 21

In the small intestine

Question 22

How are bile salts secretetd/

Answer 22

By the gallbladder.

Question 23

When are bile salts released?

Answer 23

At the arrival of food.

Question 24

Where does hydrolysis occur?

Answer 24

In the small intestine at the surface of emulsion droplets.

Question 25

``` Whato organ secretes lipase and the cofactor colipase? A. Stomach B. Small intestine C. Pancreas D. Fundus ```

Answer 25

C.

Question 26

Lipase converts triglycerides to...

Answer 26

Monoglycerides and free fatty acids

Question 27

Products of fat digestion are insoluble in water especially...

Answer 27

Monoglycerides and long chain fatty acids

Question 28

Absorption is the passage of substances from the ___ lumen across the lining of the _______ into the _____ fluid and then into the blood or ______

Answer 28

GI, intestine, interstitial, lymph

Question 29

What factors affect absorption?

Answer 29

1. Motility 2. Surface area 3. Transport 4. Removal from interstitial fluid

Question 30

The greater the surface area the faster/slower the rate of absorption

Answer 30

Faster

Question 31

Which anatomical adaptations maximise surface area?

Answer 31

- Length of intestine - Circular folds - Villi - Microvilli

Question 32

Explain the paracelular pathway

Answer 32

Solutes do not cross the cell membrane. The only barrier is tight junction binding cells together.

Question 33

Paracellular pathway is _____ and _____

Answer 33

Non-selective, passive

Question 34

A cellular pathway requires solutes to cross through __ cell membranes

Answer 34

2

Question 35

If solute is not lipid soluble in a cellular pathway, it requires a ______ ________

Answer 35

Transport pathway

Question 36

Villi prevents the build up in _____ fluid

Answer 36

interstitial

Question 37

Osmosis is the ____ movement of water from the _____ to the _____

Answer 37

passive, lumen, blood

Question 38

How are NA+ molecules actively transported across cell membranes?

Answer 38

- By themselves - Couple to monosaccharides (glucose) - Couple to amino acids

Question 39

To get into the cell, NA+ moves down/up it's concentration gradient, and to get out of the cell mit goes down/up its concentration gradient

Answer 39

Down, up

Question 40

How are carbohydrates transported via the cellular pathway?

Answer 40

Co-transported with NA+

Question 41

The apical membrane transports _____ while the basolateral membrane transports _____

Answer 41

Na+, Glucose

Question 42

The main site of absorption is in the...

Answer 42

Small intestine

Question 43

The least absorption takes place in...

Answer 43

The stomach, esophagus and mouth

Question 44

How is vitamin B12 absorbed?

Answer 44

In the ileum by binding to an intrinsic factor

Question 45

How are fat soluble vitamins absorbed?

Answer 45

Absorbed with fats