Digestion 3 Flashcards

1
Q

what are the three types of carbohydrates

A

polysaccharides
disaccharides
monosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

two are the two types of polysaccharides

A

starch and cellulose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the three types of disaccharides

A

sucrose, maltose, and lactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the three types of monosaccharides

A

glucose, fructose, galactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what type of carbohydrates can humans absorb?

A

monosaccharides
the other types have to be broken down further into things we can digest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is starch broken down into

A

individual glucose molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how are carbohydrates broken down in the oral cavity

A

broken down by salivary amylase produced by salivary glands
starch molecules are made of glucose molecules; salivary amylast breaks the bonds between the glucose molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why can’t carbohydrates be broken down in the stomach

A

salivary amylase is inavtivated by the stomach’s chyme
carbohydrates must be broke down in the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how are carbohydrates broken down in the small intestine

A

broken down by pancreatic amylase produced in the pancreas
pancreatic amylase continues digestion of starch
we get maltose, glucose, and oligosaccharide strand
brush border enzymes complete starch breakdown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

which three brush boarder enzymes complete starch breakdown

A

dextrinase, glucoamylase, and maltase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how do dextrinase and glucoamylase work to complete starch breakdown

A

break bonds between glucose subunits of oligosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how does maltase work to complete starch breakdown

A

breaks bonds between a maltose molecule (molecule with 2 glucose molecules)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what does lactase do

A

digests lactose molecule into glucose and galactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does sucrase do

A

digests sucrose molecule into glucose and fructose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

explain how monosaccharides are absorbed

A

transported across the intestinal epithelial lining and into the blood by secondary active transport
sodium and potassium are pumped against their concentration gradient using a sodium/potassium ATPase pump
energy created allows monosaccharides to move through a monosaccharide carrier into the blood
they move across the basolateral membrane by facilitated diffusion then enter blood via intercellular clefts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

where do monosaccharides go once they get into blood and what are they used for there

A

once in the venous blood, monosaccharides go to the liver
fructose and galactose converted to glucose
glucose can then be used for energy, converted and stored as glycogen, or converted into fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how is protein broken down in the stomach

A

pepsinogen is activated to become pepsin
pepsin denatures proteins to facilitate chemical breakdown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the fiber adding bulk to the lumen content

A

cellulose, a carbohydrate component of plant cell wall that we can’t digest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the structure of a protein molecule

A

polymer made of amino acid subunits that are linked by peptide bonds

20
Q

how is protein digested in the stomach

A

starts to be digested by the activated form of pepsinogen, pepsin

21
Q

how is protein broken down in the small intestine

A

enzymes released from the pancreas continue protein digestion

22
Q

what are the 3 enzymes released by the pancreas to assist protein breakdown in the small intestine

A

trypsinogen, chymotrypsinogen, and procarboxypeptidase

23
Q

where is enteropeptidase released from and what does it do

A

released from brush border of epithelial cell
activates trypsinogen to trypsin

24
Q

what does trypsin do

A

activates more trypsinogen to trypsin
activates chymotrypsinogen to chymotrypsin
activates procarboxypeptidase to carboxypeptidase
also breaks bonds between specific amino acids to produce smaller strands of peptides

25
Q

what do trypsin and chymotrypsin do

A

break bonds between specific amino acids to produce smaller strands of peptides

26
Q

what does carboxypeptidase do

A

breaks bonds between amino acids on carboxyl end and the remaining protein

27
Q

where is dipeptidase released from and what does it do

A

released from brush border of epithelial cells
breaks final bond between two amino acids

28
Q

what does aminopeptidase do

A

generates free amino acids which are used as building blocks for new proteins or converted into glucose

29
Q

what is a triglyceride molecule made of

A

glycerol and three fatty acids

30
Q

what are the 2 enzymes that break down lipids in the stomach

A

lingual lipase and gastric lipase

31
Q

what produces gastric lipase

A

chief cells of the stomach

32
Q

how is lipid digested in the stomach

A

lingual lipase and gastric lipase digest 30% of triglycerides to diglyceride and fatty acid

33
Q

how are lipids digested in the small intestine

A

pancreatic lipase digests triglycerides (in micelles) into monoglycerides and two fatty acids
requires triglycerides to be emulsified first

34
Q

how does emulsification work for lipid digestion

A

bile salts from the liver and gallbladder emulsify lipid droplets to form micelles

35
Q

explain the organization of a micelle

A

molecules with polar head and nonpolar tail
nonpolar tails line up around fat droplet with heads toward the aqueous fluid
allows greater access of pancreatic lipase to triglyceride

36
Q

how are lipids absorbed

A

monoglycerides and free fatty acids are transported to epithelial lining by micelles
they enter the cells, bile salts stay in the lumen
in the cell, monoglycerides and free fatty acids re-form into triglycerides and are wrapped in protein to form chylomicrons
chylomicrons are released by exocytosis and enter lacteals to get to the blood

37
Q

what are nucleic acids and what are the two types

A

polymers of nucleotides
DNA and RNA

38
Q

what makes up a DNA and RNA molecule

A

sugar, phosphate group, and nitrogenous base

39
Q

how are nucleic acids broken down in the small intestine

A

deoxyribonuclease and ribonuclease released by the pancreas break phosphodiester bonds between nucleotides of DNA and RNA
phosphatase and nucleosidase from brush border
phosphatase breaks bonds holding phosphate
nucleosidase breaks bonds between sugar and nitrogenous base

40
Q

what is hepcidin and what does it do

A

hormone released from the liver
inhibits absorption of iron

41
Q

which vitamins are water soluble and how are they absorbed

A

B and C
absorbed through diffusion and active transport

42
Q

which vitamins are fat soluble and where are they absorped

A

A, D, E, and K
absorbed in small intestine with lipids

43
Q

how is water absorbed

A

by osmosis

44
Q

where and how are electrolytes absorbed

A

absorbed mostly in the small intestine
usually unregulated and dependent on diet

45
Q

how is vitamin B12 absorbed

A

by receptor-mediated endocytosis
requires intrinsic factor which is formed by parietal cells in the stomach