SI Digestion & Absorption Part 2 (midterm)

Question 1

Pancreatic amylase is found in the ____ and breaks down starches/carbs. Pancreatic amylase came from ___________

Answer 1

SI, pancreatic juice

Question 2

SI enzymes from crypts of lieberkuhn go to work on remaining disaccharides. What are the 3 SI enzymes that do this?

Answer 2

maltase, surcase, and lactase

maltase breaks down maltoses into 2 glucoses

sucrase breaks down sucroses into glucose and fructose

lactases breaks down lactose into galactose and glucose

note: for lactose intolerant patients they would have low supply of lactase

Question 3

Which enzyme is found in the mouth and digests carbs?

Answer 3

salivary amylase

Question 4

Does the esophagus or stomach digest carbs?

Answer 4

NO

Question 5

In the duodenum, there is pancreatic amylase and brush border enzymes to help with the digestion of carbs. What does pancreatic amylase breakdown specifically?

Answer 5

oligosaccharides

Question 6

In the duodenum, there is pancreatic amylase and brush border enzymes to help with the digestion of carbs. What are the brush border enzymes and what do they breakdown?

test q

Answer 6

destrinase and glucoamylase break down oligosaccharides

maltase, sucrase, and lactase breakdown disaccharides into monosaccharides

Question 7

In the duodenum, there is pancreatic amylase and brush border enzymes to help with the digestion of carbs. Most of the carbs are absorbed as…

test q

Answer 7

monosaccharides

Question 8

In the duodenum, there is pancreatic amylase and brush border enzymes to help with the digestion of carbs. Most carbs are absorbed as monosaccharides. What monosaccharides are absorbed through secondary active transport and which are through facilitated diffusion?

test q

Answer 8

glucose is absorbed through sodium cotransport (secondary active transport)

fructose is absorbed through a simple diffusion with carrier protein known as facilitated diffusion

note: if you don’t have enough sodium, then you cannot absorb glucose!!

Question 9

What else is cotransported with sodium, besides glucose?

Answer 9

AAs

Question 10

_______ denatures or unfolds proteins in the stomach and __________ turns proteins into peptides

Answer 10

HCl, pepsin

Question 11

T/F: the pancreas produces enzymes for 3 of the food categories: carbs, lipids, proteins

test q

Answer 11

true!!!!

Question 12

What digestive enzymes are made in the pancreas that will go to the small intestine?

Answer 12

amylase, lipase, and proteases

Question 13

In the small intestine, there are brush border enzymes (__________) which help with the digestion of proteins. Most are absorbed as dipeptides, tripeptides, and as free AAs. Smaller AAs are cotransported with sodium. Some larger AAs and peptides are transported by membrane transport proteins

test q

Answer 13

peptidases

Question 14

Why aren’t AAs absorbed by diffusion?

Answer 14

-because they’re amiphatic
-because some have a charge

Question 15

Which enzyme begins the digestion of lipids and where?

Answer 15

lingual lipase is found in the mouth

Question 16

Where does most lipid digestion occur for adults?

Answer 16

small intestine

Question 17

Where does bile come from?

Answer 17

gallbladder

Question 18

Most lipid digestion in adults occurs in the SI. Lipids are emulsified in the SI by bile of globules of triglycerides. What does pancreatic lipase do here?

Answer 18

splits TGs into FAs and MGs

Question 19

Are there lipases in the brush border?

Answer 19

NO

Question 20

Most lipid digestion in adults occurs in the SI. Lipids are emulsified in the SI by bile of globules of triglycerides. Pancreatic lipase splits TGs into FAs and MGs. MGs and FAs are then carried in ________ that are covered in bile to surfaces of microvilli. Fats diffuse from micelles to the interior of enterocytes of the microvilli. Fats become incorporated into the ER and are formed into TGs and transported as ______________, while micelles remain in chyme. Short and medium chain TGs (relatively more water soluble) are either absorbed directly into ________ or by lymphatics

test q

Answer 20

micelles, lymph chylomicrons, portal blood

Question 21

T/F: cell membranes allow lipid soluble molecules through

Answer 21

true

Question 22

Lymphatic capillaries are called lacteals in regards to digestion. They have cells that overlap which allow chylomicrons to get through and will then go to the ______________ and then liver

Answer 22

thoracic duct

Question 23

What enzymes are found in pancreatic juice and helps with the digestion of nucleic acids?

Answer 23

ribonuclease and deoxyribonuclease

Question 24

What brush border enzymes help with digestion of nucleic acids?

Answer 24

nucleosideases and phosphatases