Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gastro 1 > Lecture 9 and 10 > Flashcards

Lecture 9 and 10 Flashcards

1
Q

What percentage of the western diet is protein?

A

30%

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

How many proteinogenic amino acids are there?

A

20- these are the ones encoded by DNA.

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

How many of the 20 amino acids are essential in diet?

A

9

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

What are the other 4 amino acids found in proteins produced from post-translational modification?

A

y-carboxyglutamate, hydroxylysine, 4-hydroxyproline and 3-hydroxyproline.

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

What percentage of the body is made of protein?

A

14%

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

What are some structural proteins?

A

Collagen, ligaments, tendons

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

What are some functional proteins?

A

hormones, enzymes, membrane proteins like transporters, muscle filaments

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

What are some amino acid neurotransmitters?

A

GABA, glutamate, glycine

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

What receptor does glutamate activate?

A

TIR1/TIR2.

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

What is orthenine used in?

A

Urea cycle

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

What are taurine and betaine used as?

A

osmolytes

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

what is beta-alanine found in?

A

The naturally occurring dipeptide carnosine

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

What is in high concentrations in breast milk?

A

Taurine

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

What is the average daily intake of protein in diet?

A

70-100g. This makes up 50% of the protein entering the GI tract. This is the exogenous source.

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

What are the endogenous sources of protein entering the GI tract?

A

enzymes, hormones, immunoglobulins, desquamated epithelial cells.

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

What are the three stages of protein digestion?

A

Intraluminal, membrane and cytoplasmic.

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

What digests protein in the lumen?

A

Pepsin and pancreatic enzymes

18
Q

Name three examples of pancreatic proteases

A

trypsin, chymotrypsin, carboxypeptidases A and B.

19
Q

What are the products of intralumenal digestion?

A

Oligopeptides or single amino acids.

20
Q

Approximately how many surface proteases and peptidases are there at the SI membrane?

A

10

21
Q

What are the products of membrane digetsion?

A

di and tri peptides

22
Q

What is the apical transporter of di and tri peptides?

A

PepT1

23
Q

How many amino acid transporters are there at the BBM?

A

7

24
Q

How many amino acid transporters are there at the BLM?

A

9

25
Q

What was the classical hypothesis?

A

Stated that all proteins were broken down to single amino acids at the surface and could only be absorbed this way.

26
Q

What was the dual hypothesis?

A

Both amino acids and di/tri peptides could be absorbed.

27
Q

What is Hartnup disorder a problem with?

A

Absorption of neutral amino acids

28
Q

How does the study on Hartnup patient prove there to be different amino acid transporters?

A

Because the patients cannot absorb alanine, a neutral amino acid, but can absorb arginine, a cationic amino acid. They can also absorb di-peptides.

29
Q

What is cystinuria a problem with?

A

Absorption of cationic amino acids.

30
Q

Which form would the classical hypothesis suggest is absorbed more readily? Glycine monomer, dimer, trimer or tetramer?

A

A monomer.

31
Q

What is the kinetic advantage of absorbing di or tri peptides?

A

Every time the transport protein goes through its transport cycle, 2 or 3 amino acids are moved across rather than 1.

32
Q

What is the acid microclimate and where is it?

A

pH of 5.5-6.8 at the top 1/3 of the villi.

33
Q

Why did they use Gly-Sar?

A

It is a hydrolysis resistant dipeptide.

34
Q

What is valinomycin?

A

A ionophore which inserts K+ channels into the membrane to make the inside more negative.

35
Q

Describe dipeptide transport.

A

Na+ independent, pH dependent and enhanced by a negative inside membrane potential. Driven by the proton electrochemical gradient.

36
Q

What is BCECF?

A

A pH dependent fluorescent dye.

37
Q

When the dipeptide is added outside, what is seen inside the BBMV?

A

acidification

38
Q

Where is PepT1 predominantly expressed?

A

In the small intestine

39
Q

Is there any other dipeptide transporter?

A

No- we know this because fluid absorption is abolished when PepT1 is knocked out.

40
Q

How is the acid microclimate maintained during absorption?

A

NHE3

41
Q

Does Na+ uptake increase with dipeptide uptake?

A

Yes

42
Q

What is S1611?

A

A selective inhibitor of NHE3

Gastro 1 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions