Brainscape's Knowledge GenomeTM

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


See full index

Nutritional Physiology > Metabolism > Flashcards

Metabolism Flashcards

1
Q

Where is water absorbed?

A

Mostly small intestine

Some in stomach and large intestine

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

How is water absorbed?

A

Via osmotic gradient

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

What is the transcellular route?

A

Crosses basolateral and apical membranes

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

What is the paracellular route?

A

Molecules move straight through intercellular space

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

What are the characteristics of electrolyte/mineral absorption?

A
  • active or passive

- used to set up osmotic gradient

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

The colon has …… tight junctions

A

Tight

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

The small intestine has ……… tight junctions

A

Leaky

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

Na+/K+ ATPase pump

A
  • pumps potassium into the cell

- pumps Na+ out of cell

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

Sodium concentration is very …… in cells

A

Low

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

Potassium concentration is ….. in cells

A

High

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

Most of the water in the GIT is …………. water

A

Endogenous water

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

Where is lots of the water secreted?

A

Duodenum

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

Where is most water reabsorbed in the SI?

A

Ileum

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

What are the different ways of absorbing sodium?

A
  1. Passive diffusion (distal colon)
  2. Na+ glucose or Na+ amino acid transport (jejunum, ileum)
  3. Na+ H+ exchange (duodenum, jejunum)
  4. Parallel Na+ H+ and Cl- HCO3- exchange (ileum, proximal colon)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why is the secretion of chloride important?

A

Secrete chloride : water follows

Cystic fibrosis transmembrane regulator

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

What is the most common absorption pathway of chloride?

A

Chloride channels open and it will follow sodium

Can also travel paracellularly

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

What are the types of calcium secretory cells?

A
  • Ca2+ activates
  • volume regulated
  • ligand gated
  • cystic fibrosis transmembrane regulator
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does the CFTR channel work?

A
  • cAMP activates PKA

- phosphorylates the pump

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

Anything that increases cAMP will ……… chloride secretion

A

Increase

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

What are the routes of K+ absorption?

A
  • paracellularly

- distal colon: K+/H+ antiport

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

What does bioavailability depend on?

A
  • pH
  • redox state of metal
  • dietary complexes which enhance solubility
  • dietary complexes which diminish absorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is calcium absorbed?

A
  • active trancellular route in duodenum - Vit D

- paracellular diffusion

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

How is calcium actively absorbed?

A
  1. Calcium pumps on the basal lateral membrane actively pump calcium out of cells
  2. CAT1 is vitamin D responsive
24
Q

How is magnesium absorbed?

A
  1. Active magnesium transporters on basolateral membrane pump magnesium out
  2. Passive transporter in
25
Q

Fat soluble vitamins are absorbed ……….

A

The same way that fats are

26
Q

Every B and C vitamin has………

A

It’s own transporter

27
Q

How is folate (B9) absorbed?

A
  1. Folate conjugases chop off all glutamates except for 1 (rate limiting step)
  2. Transported by a folate carrier (antiport of OH-)
  3. Reduced to dihydrofolate and then trihydrofolate
  4. Methylated by methylase so that it is soluble
28
Q

What makes B9 hard to absorb?

A

It is a polymer - has glutamate residues

29
Q

How is vitamin B12 transported?

A
  1. B12 binds to haptocorrin in stomach
  2. Intrinsic factor is produced in stomach and is glycosylated (prevents digestion)
  3. Proteases in duodenum remove haptocorrin
  4. B12 binds to intrinsic factor
  5. Complex is taken up by receptor mediated endocytosis
  6. Complexed with trans cobalamin 2
  7. Exocytosed into blood
30
Q

What enters the blood stream in a villus?

A
  • amino acids
  • monosaccharides
  • SCFAs
31
Q

Where are brush border enzymes found?

A

Embedded in membrane that lines intestine

32
Q

What does enterokinase do?

A

Converts trypsinogen to trypsin

33
Q

What is the common point for the conversion of macronutrients to energy?

A

Acetyl CoA

34
Q

Digestible carbs produce …..

A

4kcal/g

35
Q

What does amylase break down starches into?

A
  1. Maltotriose
  2. Maltose
  3. Alpha-limit dextrins
36
Q

What are the 2 important carbohydrate enzymes in the brush border?

A
  • glucoamylase

- sucrase-isomaltase

37
Q

What does glucoamylase do?

A

Breaks down moltotriose and moltose into monosaccharides

38
Q

What does sucrase-isomaltase do?

A
  • isomaltase breaks down alpha-limit dectrins

- sucrose breaks down sucrose to fructose and glucose

39
Q

What transports galactose and glucose into cells?

A

SGLT1

40
Q

What transports fructose into cells?

A

GLUT5

41
Q

What transports monosaccharides on the basolateral side?

A

GLUT2 (not insulin dependent)

42
Q

What happens in lactase deficiency?

A
  • disaccharides stuck in large intestine
  • has osmotic activity: pulls water across - diarrhoea
  • bacteria break it down: produce hydrogen and CO2 gases
43
Q

Where is lactase usually found?

A

Brush border

44
Q

Hydrogen in breath ………. in lactase deficiency

A

Increases

45
Q

What turns glycogen into glucose?

A

Glucose-6-phosphatase

46
Q

Digestion of proteins outline

A
  • pepsins in stomach digest 10-15%
  • pancreatic proteases in SI convert 70% to oligopeptides and 30% AAs
  • peptideses in brush border
47
Q

How are amino acids/Di and tri peptides absorbed?

A
  • amino acids: Na+ contransporter

- di- and tri-peptides: H+ co-transporter (H+ gradient produced by Na+/H+ antiport)

48
Q

How are amino acids absorbed on the basolateral side?

A

Different types of sodium independent transporters

49
Q

What is the deamination of AAs?

A

AAs - Keto acid + Ammonia

50
Q

What occurs in the liver in terms of protein metabolism?

A

Deamination
Transmigration
Synthesis of plasma proteins
Synthesis of urea

51
Q

If you are protein deprived, you …………. concentrate urine

A

Can’t

52
Q

What are the main types of lipids? (3)

A

Triglycerides
Phospholipids
Cholesterol

53
Q

How is fat absorbed?

A

Moves across plasma membrane, also carrier mediated transport

54
Q

What does carnatine do?

A

Transports FAs across mitochondrial membrane in exchange for a feee carnitine

55
Q

What is the process of B-oxidation of fats?

A
  1. Oxidation (reduces FAD)
  2. Hydration
  3. Oxidation (reduces NAD)
  4. Thiolysis

Produces AcetylCoA

56
Q

How much ATP does fat give rise to?

A

14-17 ATP molecules

57
Q

What is the rate limiting step of B-oxidation?

A

Carnitine acyl transferase

Nutritional Physiology (13 decks)

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