Exam 4 - Digestive System 5

Question 1

Why hydrolyzes DNA and RNA to nucleotides?

Answer 1

Nucleases

Question 2

What splits nucleotides into phosphate ions, ribose, and deoxyribose sugar and nitrogenous bases?

Answer 2

Nucelosidases and phosphotases

Question 3

How are vitamins absorbed?

Answer 3

unchanged

Question 4

Vitamins absorbed w/ other lipids

Answer 4

A , D, E, and K

Question 5

Vitamins absorbed by simple diffusion

Answer 5

B complex, and C; B12 is bound to intrinsic factor

Question 6

Where are minerals absorbed?

Answer 6

all along the small intestine

• Na cotransported w/ sugars and amino acids
• Cl exchanged for bicarbonate
• iron and calcium absorbed as needed

Question 7

How much water does the digestive tract receive per day?

Answer 7

9 L

• .7 L from food, 1.6 L in drink, 6.7 L IN GASTROINTESTINAL SECRETIONS
• 8L IS ABSORBED BY SMALL INTESTINE, 0.8 L by large intestine

Question 8

Water voided in the feces

Answer 8

1.2 L

Question 9

How is water absorbed?

Answer 9

by osmosis following the absorption of salts and organic nutrients

Question 10

When does diarrhea occur?

Answer 10

When too little water is absorbed

• feces passes too quickly due to intestinal irritation
• feces contain high concentrations of a solute

Question 11

When does constipation occur?

Answer 11

When too much water is absorbed

• feces passes too slowly and become “hard”
• lack of exercise, emotional upset (sympathetic nervous system things)

Question 12

Mucosa of the large intestine

Answer 12

mostly simple columnar epithelium (like the small intestine) but the anal canal has stratified squamous epithelium