Biochemistry Exam II

Question 1

What do you lose when vomiting

Answer 1

H20, H+, K+, Cl-

Question 2

Increased intestinal secretion can lead to

Answer 2

Diarrhea

Question 3

Leads to dehydration and metabolic acidosis

Answer 3

Severe Diarrhea

Question 4

Production of Fluid and Digestive Enzymes for Homogenization, lubrication and digestion of carbohydrate (AMYLASE) and lipid (LINGUAL LIPASES).

Answer 4

Salivary Glands

Question 5

Secretion of HCl and proteases to initiate hydrolysis of proteins

Answer 5

Stomach

Question 6

Biocarbonate, Proteases, and Lipases to continue digestion of protein and lipids; and amylase to continue digestion of starch.

Answer 6

Pancreas

Question 7

Secretion and storage of bile acids for release into the small intestine

Answer 7

Liver and Gall Bladder

Question 8

Final intraluminal digestion of food, digestion of carbohydrate dimers and specific absorptive pathways for digested material

Answer 8

Small Bowel

Question 9

Absorption of fluid and electrolytes and products of bacterial action in colon

Answer 9

Large Bowel

Question 10

Most digestive enzymes in the GI tract are secreted as ______

Answer 10

Zymogens, or inactive enzyme precursors

Question 11

How are zymogens activated

Answer 11

Changes in pH, Enteropeptidases

Question 12

All enzymes ______ their substrates

Answer 12

Hydrolyze (Hydrolases)

Question 13

1st stage of digestion

Answer 13

Mouth (chewing)

Question 14

Secretion of saliva controlled by

Answer 14

PNS** and SNS

Question 15

Main absorptive surface as such is lined with mucosal folds

Answer 15

Small Intestine

Question 16

Important for digestive process and preservation of tissues of stomach and intestine

Answer 16

pH

Question 17

Saliva is ________
Lumen is _____
But Lumina mucus is ______
Acid is counteracted by ______

Answer 17

Alkaline
Strongly acidic
Alkaline
Alkaline Pancreatic secretions of the Duodenum

Question 18

Main Polysaccharides

Answer 18

Starch (amylose) (plant)–Potatoes, rice, bread, onions

Amylopectin (glycogen) (plant, & animal)–Potatoes, rice, bread, muscle, liver

Question 19

Most common Disaccharides

Answer 19

Sucrose–Desserts, sweets ‘sugar’

Lactose–Milk

Question 20

Most common Monosaccharides

Answer 20

Fructose–Fruits, honey
Glucose–Fruits, honey
–>Require no further digestion

Question 21

Necessary for the digestion of starch and glycogen

Answer 21

Salivary/pancreatic Amylase

Question 22

The initial digestion _____ which occurs free in the lumen, whereas the final processes invole a-glucosidases and isomaltase, which are attached to the mucosal membrane of the ______

Answer 22

Amylase

Enterocyte

Question 23

Primary monosaccharides resulting from the digestion of dietary carbohydrates

Answer 23

Galactose (Na-dependent glucose transport)
Glucose (Na-dependent glucose transport)
Fructose (Na Independent facilitated transport)
–>Into Enterocyte at Mucosa membrane

Question 24

• 90% of fat in diet
• Degraded to fatty acids–act as surfactants
• Remainder: Cholesterol, Cholesteryl ester, phospholipids, and non-esterfied fatty acids (NEFA)

Answer 24

Triacylglycerol (TAG)

Question 25

Initial change in physical nature of lipids occurs in

Answer 25

Stomach

Question 26

Core body temp within stomach helps _______dietary lipids

Answer 26

Liquefy

Question 27

Peristaltic movements (PNS) aid in the formation of

Answer 27

Lipid Emulsion

Question 28

Salivary and Gastic Lipases aid in

Answer 28

Emulsification

Question 29

______of Dietary fats are citical for digestion/absorption of lipids

Answer 29

Emulsification

Question 30

Bile salts and pancreatic enzymes are active in the

Answer 30

Duodenum

Question 31

_____are essential for solubilizing lipids during digestion

Answer 31

Bile Salts

Question 32

The fate of fatty acids entering enterocytes is dependent on their

Answer 32

chain length

Question 33

Medium and short-chain fatty acids____pass directly through the ______ cells into the _____ blood supply

Answer 33

<10 Epithelial cells Hepatic Portal

Question 34

Fatty acids of more than ____ carbon atoms are bound to a fatty acid binding protein and transferred to the ______ of the enterocyte for resynthesis into _____

Answer 34

>12 Rough ER TAGs

Question 35

Fatty acid activation is accomplished by the production of acyl-CoA derivatives by

Answer 35

Acyl-CoA Synthase

Question 36

All long-chain fatty acids absorbed by the intestinal epithelial cell are thus reutilized to form TAG before being transferred to the lymphatic system as ______

Answer 36

Chylomicrons

Question 37

Large particles that transport exogenous lipids from the gut

Answer 37

Chylomicrons

Question 38

99% lipid, 1% protein Assembled within enterocytes on Rough ER Released into the intercellular space by exocytosis Leave the intestine via the lymphatic system

Answer 38

Chylomicrons

Question 39

Total protein load received by the gut is

Answer 39

70-100g dietary protein per day 35-200g of endogenous protein -secreted into gut (mostly enzymes) -shed from epithelium as a result of cell turnover

Question 40

Absorption of protein is extremely efficient

Answer 40

1-2 g of nitrogen and 6-12 g of protein excreted daily. Low compared to intake

Question 41

Proteins are hydrolyzed by

Answer 41

Peptidases

Question 42

Protein absorption begins in the

Answer 42

Stomach

Question 43

Secreted HCL in stomach reduces the pH to ____ causing denaturation of dietary proteins

Answer 43

1-2 (more susceptible to protease activity)

Question 44

Zymogen/enzyme: Pepsinogen A Activation: HCl Substrate: Protein EndProduct: Peptides

Answer 44

Stomach (Fundus)

Question 45

Zymogen/enzyme: Pepsinogen B Activation: 1-2 autoactivation Substrate: Protein Endproduct: Peptides

Answer 45

Stomach (Pylorus)

Question 46

Trypsinogen Chymo-Trypsinogen Proelastase Procarboxy-peptidases

Answer 46

Pancreas

Question 47

Aminopeptidase | Dipeptidases, Endopeptidases

Answer 47

Small Intestine

Question 48

3 sites of Protein Digestion and Absorption

Answer 48

Gastic (stomach), Pancreatic, Intestinal (small)

Question 49

Autoimmune disease characterized by malabsorption of nutrients due to changes in intestinal mucosa Histologic changes are due to the interaction of pepsin/trypsin digested gluten, the principal protein of wheat, within the epithelium.

Answer 49

Celiac Disease

Question 50

No typical signs of Celiac Disease, what are general complaints

Answer 50

Intermittent diarrhea Abdominal pain Bloating

Question 51

Up to 89% of people with Celiac disease can exhibit dental enamel defects like:

Answer 51

Demarcated opacities Undersized teeth Yellowing Grooves and/or pitting on one or more permanent teeth

Question 52

Changes in ______ may be the only sign for an otherwise symptomless Celiac disease

Answer 52

Permanent teeth | -->calcium and vitamin D deficiences lead to cavities