Digestion and Absorption of Carbohydrates

Question 1

What is digestion and mobilisation?

Answer 1

the process in the alimentary canal by which food is broken up physically, as by the action of the teeth, and chemically, as by the action of enzymes, and converted into a substance suitable for absorption and assimilation into the body.

Is when the liver and muscle do G6p
In feeding both
In fasting only liver muscle ATP

Question 2

Diff in the structure of starch/glycogen.?

Answer 2

starch
Polysaccharide 
Alpha 1-4. linkages 
Amylose ( strictly linear chain )
Amylopectin ( branched chain containing alpha 1-6 linkages)
glycogen
More branched

Question 3

Both Amylopectin and glycogen have same linkages?

Answer 3

Yes

Alpha 1-6 glucosidase

Question 4

Cellulose like he’s ?

Answer 4

B 1-4 linkages

Question 5

Why must food be broken down?

Answer 5

1. Only small molecules can pass through
   membranes
2. Digestive systems are adapted to the type
   of food the organism uses

Question 6

Digestion Composed of Two Processes

?

Answer 6

Physical

Chemical

Question 7

What physical Digestion??

Answer 7

1-Breakdown larger to small
2- Increase surface area
3-Teeth, gizzard, movements of digestive tract

Question 8

Features of stomach

Answer 8

expandable muscular sac

Pyloric sphincter

Stores food;

Mechanically break down

Question 9

What Chemical Digestion??

Answer 9

Breaking down complex food

Enzymes

Question 10

What is the fate of glucose?

Answer 10

Energy production

Storage as glycogen

Question 11

Steps of working enzymes on Starch & Glycogen..?

Answer 11

1-begins mouth (salivary α-amylase converts starch to smaller polysaccharides called α-dextrins )
2-Pancreatic α-amylase continues digestion of α-dextrins into maltose, maltotriose and oligosaccharides called limited dextrins .
3-maltose, maltotriose, sucrose and lactose continues by disaccharidases attached brush border (microvilli) of intestinal epithelial cells
4-monosaccharides produced are transported into the intestinal cells

Question 12

Example of enzymes that convert disaccharide to monosaccharides?

Answer 12

Glucosamylase
Sucrase-Isomaltase Complex
Lactase

Question 13

Function of Glucosamylase?

Answer 13

Begins at non-reducing ends of limited dextrin and sequentially hydrolyzes α-(1- 4) glycosidic bonds to produce glucose.

digest limited dextrin down to isomaltose.

Question 14

Function of the Sucrase-Isomaltase Complex? (Maltese)

Answer 14

sucrase-maltase site accounts for 100% of intestinal ability to hydrolyze sucrose in addition to maltase activity.

The isomaltase-maltase site accounts for almost all activity to hydrolyze α 1-6 bonds in addition to maltase activity

Question 15

Function of lactase ?

Answer 15

hydrolyzes lactose and the β-bonds between glucose or galactose and ceramide in glycolipids

Question 16

If there is a deficiency of lactase what disease will happen?

Answer 16

Lactase inforance

Question 17

Carbohydrates can’t be digest by human enzymes ?

Answer 17

Dietary Fiber

Cellulose

Question 18

Example of Dietary Fiber

Can not be digest by human?

Answer 18

Derivatives of lignan (cellulose, hemicellulose, lignin, pectins, mucilages and gums)

Question 19

Bacterial flora of the colon metabolize the fibers to?

Answer 19

gases(H2,CO2,CH4) and short chain fatty acids.

Question 20

Fatty acids are absorbed by?

Function of fiber?

Answer 20

colonic cells.

Fibers soften the stool, thereby reducing pressure on the colonic wall and enhancing expulsion of feces

Question 21

regulation Hormones gastrointestina tract ?

Answer 21

Gastrin
Secretin
Cholecystokinin (CCK)

Question 22

Functions of Gastrin regulatory?

Answer 22

it triggers the secretion of gastric
juice.

consists hydrochloric acid, break apart fibrous matter in food and kills bacteria, and pepsinogen, which is a precursor of the protein-splitting enzyme pepsin.
increases the motility of the stomach
increases the motility of the upper small intestine and the gallbladder

Question 23

Function of Secretin regulatory ?

Answer 23

secretin is released into the bloodstream and
stimulates the acinar cells of the pancreas to secrete
water and bicarbonate

By this mechanism hydrochloric is
promptly diluted and neutralized

Secretin also inhibits the secretion of gastrin, which
triggers the initial release of hydrochloric acid into the
stomach, and delays gastric emptying.

Question 24

Function of cck Hormones?

Answer 24

stimulates the gallbladder
to contract and release stored bile into the
intestine

stimulates the secretion of
pancreatic juice and may induce satiety.

Question 25

Health Effects of Starch and Fibers?

Answer 25

• protection from heart disease and stroke
  1-Soluble fibers bind with bile and thereby lower blood cholesterol levels.
  2-Fiber may also displace fat in the diet.
• Reduce the risk of type 2 diabetes by
  decreasing glucose absorption.
• Enhance the health of the GI tract which can
  then block the absorption of unwanted particles .
• May protect against colon cancer by removing
  potential cancer-causing agents from the body
• Promote weight control because
  complex carbohydrates provide less
  fat and added sugar.
  *

Question 26

Harmful effects of excessive fiber

intake.?

Answer 26

• Displaces energy and nutrient-dense foods
• Abdominal discomfort and distention
• May interfere with nutrient absorption

Question 27

Gastroesophageal Reflux Disease in general

?

Answer 27

mucosal damage produced
by the abnormal reflux of gastric content
into the esophagus

Question 28

Factors that can aggravate GERD?

Answer 28

– Diet: caffeine, coffee, peppermint,
citrus, alcohol , smoking
– Position: Bending, straining
– Pregnancy
-hiatal hernia

Question 29

What is hiatal hernia??

Answer 29

hiatal hernia
happens when the upper part of the
stomach and LES (lower esophageal
sphincter) move above the diaphragm

Question 30

What is Celiac Disease ??

Answer 30

serious sensitivity to gluten, which
is a protein found in wheat, rye, and barley.

Eat gluten, and your immune system
goes on the attack: It damages your villi

Question 31

Symptoms of celiac disease??

Answer 31

children

include abdominal pain and bloating, diarrhea, constipation, vomiting, and weight loss.

adults
include anemia, fatigue, bone loss, depression, and seizures.

Question 32

What is Crohn’s Disease ?

Answer 32

inflammatory bowel disease (IBD).

commonly affects the terminal ileum, which connects
the end of the small bowel and the beginning of the
colon.

Question 33

symptoms of Crohn’s Disease ??

Answer 33

abdominal pain, diarrhea, rectal

bleeding, weight loss, and fever.

Question 34

What is Ulcerative Colitis ??

Answer 34

inflammatory bowel disease. Symptoms
are similar to those of
Crohn’s.

Question 35

Glucose Absorption types ?

Answer 35

Active

Na+ dependent:

Passive

Facilitated passive
transport known as Glut 1 -4

Question 36

glucose transporters.

To enter the cells ??

Answer 36

▪ GLUT-1: Enables basal non- insulin
stimulated
glucose
uptake
(erythrocytes)
▪ GLUT-2: Transports glucose into beta
cells, a pre- requisite for glucose
sensing.
▪ GLUT-3: Enables non-insulin
mediated glucose uptake into brain.
▪ GLUT-4: Enables much of the
peripheral action of insulin (muscles,
adipose)