Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Phys Phinal (Annie & Lauren) 💩🚽 > Digestion And Absorption (Lauren) > Flashcards

Digestion And Absorption (Lauren) Flashcards

1
Q

When food gets to the digestive compartments, is it a size that we can absorb?

A

No, we need to break foodstuffs down into smaller sizes that can absorbed.

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

In a molecule of glycogen or starch, glucose molecules are linked to each other by ___,___ linkages and at branch points, there are ___,___ linkages

A

1,4 glucose to glucose

1,6 at branch points

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

How do we break down complex polysaccharides like glycogen and starch?

A

First break them into oligosaccharides

Then break down oligosaccharides into simple sugars (monosaccharides)

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

What kind of bonds can salivary amylase and pancreatic amylase break down?

A

1,4 only

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

What enzyme breaks down lactose?

A

Lactase

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

What enzymes break down Dextrins?

A

Maltase

Dextrinase

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

What enzymes break down maltotriose and maltose

A

Maltase

Sucrose

Dextrinase

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

What enzyme breaks down sucrose?

A

Sucrose

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

What are the products of lactose breakdown?

A

Glucose

Galactose

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

What are the products of sucrose breakdown?

A

Glucose

Fructose

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

What are the 2 main groups of enzymes that break down disaccharides and oligosaccharides

A

Galactosidases (Lactase)

a-glucosidases (sucrase, maltase, dextrinase)

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

What is another name for the enzymes that break down disaccharides and oligosaccharides into monosaccharides?

A

“Intrinsic membrane proteins”

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

How is glucose brought into the enterocyte from the lumen?

A

Secondary active transport

Comes in with the sodium gradient

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

What is the name of the transporter that brings glucose and galactose from the lumen across the apical membrane and into the enterocyte ?

A

SGLT 1

Comes in with SODIUM

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

Does SGLT1 use (active/secondary active/passive) transport to bring glucose and galactose into the enterocyte?

A

Secondary active

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

How does fructose get into the enterocyte

A

PASSIVE transport through the GLUT-5 transporter

(Don’t need active transport since there is so much more fructose in the lumen than inside the cell….it just diffuses down its gradient)

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

How do glucose and galactose travel across the basal membrane into the blood?

A

Facilitated diffusion using the GLUT-2 transporter

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

What is the main cause of disorders with carbohydrate digestion?

A

Enzyme deficiencies

Ex: lactase deficiency

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

Why do enzyme deficiencies cause you to “liquidate your assets” (aka diarrhea)

A

The unabsorbed carbs are osmotically active and hold water

🧻~~osmotic diarrhea~~
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Is lactose intolerance congenital or acquired?

A

Its usually congenital (but not evident until later in life for many ppl)

Can also be caused by long-term disease that messes up membrane lactase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

True or false: a significant amount of your protein intake comes from sloughed epithelial cells and gastric secretions

A

True 🍴

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the products of protein digestion?

A

Amino acids

Oligopeptides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What enzyme needs to be activated FIRST before any other enzymes can be activated?

A

Trypsinogen must be turned into Trypsin by ENTEROPEPTIDASE**
*********

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What enzymes does Trypsin activate?

A

Trypsinogen—> Trypsin

Chymotrypsinogen—> Chymotrypsin

Proelastase—> Elastase

Procarboxypeptidases A and B —> Carboxypeptidases A and B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What enzyme is required to activate Trypsin before any other enzymes can be activated
ENTEROPEPTIDASE
26
What happens to oligopeptidases when they get to the brush border?
Membrane bound peptidases will further break them down into AA’s OR Endocytosis of oligopeptides and immunoglobulins (from breast milk)**********
27
When you’re a little baby drinking your mommy’s breast milk and you ingest immunoglobulins, how do you absorb those without first breaking them down into individual amino acids?
Brush border cells can use endocytosis to eat them WHOLE****
28
How do Amino acids get from the lumen into the enterocytes?
Secondary active transport coupled to sodium transport (just like glucose)
29
How do dipeptides and tripeptides get from the lumen into the enterocyte?
Coupled to H+ transport** | Once inside the cell, they will get further broken down by peptidases into amino acids
30
What co-transporters shuttle amino acids from the lumen into the enterocyte?
There are 4 separate ones depending on the type of amino acid: Neutral AA’s dibasic AA’s Dicarboxylic AA’s Imino (proline)
31
What are the 3 diseases that can cause problems with protein digestion/absorption?
Pancreatic insufficiency Hartnup disease Cystinuria
32
Why does pancreatic insufficiency inhibit protein absorption?
Insufficient amount of Trypsin= malnutrition
33
How does Hartnup disease affect protein absorption?
The transporter for neutral amino acids is defective BUT you can still absorb di- and tripeptides via endocytosis, and those guys will have neutral amino acids in them. 👍 no big deal. no amino acid deficiency here
34
How does Cystinuria affect protein digestion/absorption?
Transporter for dibasic amino acids (cystine, lysine, and arginine) is absent from gut and kidney= dibasic amino acids lost in urine and feces BUT di- and tripeptides can still be sucked up via endocytosis :)
35
What makes the digestion of fats so challenging?
Fats are not water soluble, but the enzymes needed to break them down are. Fats also tend to coalesce so the surface area is small (reason we must churn and have bile emulsification)
36
What are the 4 key events in fat digestion?
Secretion of bile and lipases Emulsification by bile Hydrolysis of ester linkages Solubilizing digestion products within micelles for delivery to enterocytes
37
What are the 3 specific enzymes needed for fat digestion?
Pancreatic lipase Cholesterol ester hydrolase Phospholipase A2
38
What does pancreatic lipase do?
Cleaves FA’s off triglycerades at the 1 and 3 position
39
What protects pancreatic lipase from being destroyed by bile?
Colipase****** | No colipase= no pancreatic lipase
40
What does cholesterol ester hydrolase do?
Removes fatty acid from: Cholesterol Vitamin A, D, E, Glycerine (Non-specific esterase)
41
What does Phospholipase A2 do?
Hydrolyzes phospholipids at the 2 position
42
How do lipolytic products get through the intestinal mucosa?
Micelles diffuse through the “unstirred” later to the mucosal surface. Then they just diffuse right into the cells down their concentration gradient
43
95% of fat is removed by the (small/large) intestine
Small
44
Once all the pieces of triglycerides that were in the micelle diffuse into the cell, what happens to them?
They get reassembled into triglycerides and then turned into chylomicrons
45
What happens to chylomicrons once they are produced inside the cell?
They get EXOCYTOSED across the basolateral membranes into a lacteal. It gets carried through the lymph system to the thoracic duct where it enters the general circulation
46
What is a chylomicron?
A core of triglycerides surrounded by phospholipids and apoproteins
47
How do micelles travel around the body?
THEY FUCKING DON’T!!!! They are ONLY in the lumen of the intestine! DO NOT MIX UP MICELLES AND CHYLOMICRONS
48
What do chylomicrons do once they are in your bloodstream?
They deliver triglycerides to adipose and muscle
49
What are the 4 ingredients in chylomicrons?
Triglycerides 84%**** Cholesterol 6% Phospholipids 8% Apoproteins 2%
50
Zollinger-Ellison Syndrome is abnormal (digestion/absorption)
Digestion
51
What happens with Zollinger-Ellison syndrome?
You have a tumor that secretes gastrin which causes the small intestine to be WAY TOO acidic. All the acidity denatures pancreatic lipase and you can’t digest lipids. (= lipids in feces=steatorrhea)
52
Whipple’s Disease is abnormal (digestion/absorption)
Absorption
53
What happens with Whipple’s disease?
Underdeveloped lymph system impairs the ability to pick up chylomicrons. Leads to steatorrhea
54
Another name for enterokinase is________
Enteropeptidase
55
Do these enzymes come from the small intestine or the pancreas: Enterokinase Disaccharidases Maltase Sucrase Lactase Peptidases Aminooligopeptidase Dipeptidase
Small intestine (they are membrane proteins)
56
Do these enzymes come from the pancreas or the small intestine: Amylase Trypsin Chymotrypsin Carboxypeptidase Elastase Lipase-colipase Phospholipase
Pancreas
57
How do fat soluble vitamins travel through the lumen of the intestine?
Micelles
58
If you had no micelles for some reason, would you have a vitamin deficiency?
Yes, you would not be able to absorb fat-soluble vitamins
59
How do fat soluble vitamins enter the circulation?
In chylomicrons
60
How do water-soluble vitamins get into the enterocytes?
Na+ dependent co-transport | Secondary active transport, just like glucose
61
How does B12 get absorbed?
Bound to gastric intrinsic factor and then it gets absorbed in the ileum**
62
What part of the intestine is B12 absorbed?
ILEUM
63
Why is vitamin D required for calcium absorption?
It causes the expression of the Calcium binding protein which is the intracellular shuttle for Calcium- we don’t want a bunch of free calcium floating around inside cells
64
How does calcium get across the brush border?
Facilitated diffusion
65
How does calcium get across the basolateral membrane and into the blood?
TWO OPTIONS: Ca+ ATPase Na+/Ca+ exchanger
66
What does gastric acid have to do with the intestinal absorption of Iron?
Helps absorption and with solubilization by reducing Fe3 into Fe2
67
How does Iron travel around the blood
Transferrin
68
How does iron get stored inside cells?
In ferritin
69
If an enterocyte has a bunch of iron stored on ferritin, and then it gets sloughed off, what happens to the iron
You just poop it out
70
Where is water reabsorbed?
Small intestine Large intestine NOT stomach
71
What is the driving force for water reabsorption into enterocytes?
Water follows solutes out the basolateral membrane
72
How does Na+ get pumped out of the enterocytes?
Na+/K+ ATPase | Requires A LOT of energy
73
Water reabsorption is (isosmotic/hyposmotic)
Isosmotic | Water and solute absorption are proportional
74
What part of the intestine is the #1 site for Na+ absorption?
Jejunum*
75
How does Na+ get absorbed in the jejunum?
TWO OPTIONS: Co transported with sugar or amino acid Na+/H+ exchange (NHE)***
76
What are the 2 important things that happen as a result of the Na-H+ exchanger in the jejunum?
1. H+ that gets sent into the lumen neutralizes HCO3- 2. Na+ floats through the cell and gets transported into the blood where it will combine with an HCO3- (that came from the production of the H+)
77
In the jejunum, we end up with a net absorption of _______
NaHCO3 **************** (From the Na and the HCO3- that get transported across the basolateral membrane)
78
How does Cl- get absorbed in the jejunum?
Paracellular absorption driven by a voltage gradient
79
What additional transporter is on the apical membrane of cells in the ILEUM?
Cl-/HCO3- exchanger *** (Still have the NHE and the cotransporters for absorption of Na+)
80
What transporter is present on the basolateral membrane in the jejunum and not the ileum?
HCO3- transporter
81
What transporter is present on the basolateral membrane in the ileum and NOT in the jejunum?
Cl- transporter
82
In the ileum, what happens to the acid/base status of the lumen?
Nothing, H+ and HCO3- are both secreted into the lumen | In the ileum we are not trying to recover bicarb, we’re trying to recover Cl-
83
In the ileum there is a net reabsorption of | _________
NaCl******
84
Net reabsorption In Jejunum: In Ileum:
In Jejunum: NaHCO3 In Ileum: NaCl
85
What electrolyte gets absorbed in the colon and through what transporter?
Na+ gets absorbed through Epithelial Na+ Channels (ENaC)
86
True or false: ENaC channels in the colon are sensitive to aldosterone like they are in the kidney
True
87
What electrolyte gets secreted in the colon?
K+
88
What will cause an increased amount of K+ to be secreted into the lumen in the colon?
Increased flow/diarrhea | Increased flow will increase Na+ absorption, which will kick out more K+
89
Severe diarrhea puts you at risk of (hypo/hyper) kalemia
Hypo
90
What 3 things get lost with diarrhea?
Fluid HCO3- K+
91
Diarrhea puts you at risk for metabolic (acidosis/alkalosis)
Acidosis (loss of HCO3-)
92
What are 3 possible causes of diarrhea?
1. Decreased absorptive surface area (inflammation of small intestine) 2. Osmotic diarrhea due to unabsorbable osmolytes (lactase deficiency, MgSO4 etc) 3. Excessive secretion of intestinal fluid (Cholera)
93
How does cholera cause diarrhea?
Cholera toxin binds to apical membrane of crypt cells, and causes adenylyl cyclease to go crazy making cAMP. All the extra cAMP stimulates Cl- secretion, and water and Na+ will follow Cl-.
94
How do you treat cholera?
Pedialyte

Phys Phinal (Annie & Lauren) 💩🚽 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions