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Biochemistry 2 > Lab 11 - Determination of Vitamins > Flashcards

Lab 11 - Determination of Vitamins Flashcards

(44 cards)

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1
Q

In general, what are vitamins?

A

Accessory food factors - necessary

Needed in small amount, but cannot be produced in body.

Vitamins are used in the body usually as COENZYMES

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2
Q

The quantitative determination of vitamins has two main routs?

A
  1. To make the vitamin visible + measure the absorbance by photometry
  2. Measure effects of vitamin in biological system.
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3
Q

What is a Precursor of Vitamin A?

A

Beta carotene

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4
Q

Where is carotinase found?

A

In the intestinal wall of domestic animals

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5
Q

Where is Beta-caroten absorbed?

A

Beta-caroten is absorbed through the INTESTINAL WALL.

Then gets into the blood circulation

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6
Q

Where can the Beta-caroten be detected?

A

In the blood plasma

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7
Q

What is the absorbed beta-caroten converted into?

A

Its converted into Vitamin A

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8
Q

Where is the absorbed beta-carroten converted into Vitamin A?

A

In the LIVER and MAMMARY GLAND

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9
Q

What are beta-caroten soluble in?

A

Beta-caroten is FAT-soluble

- Thats why we need organic compounds to detect it.

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10
Q

How do you measure beta-carroten?

A

With instruments:
- PETROLETHER in extract = yellow, and INTENSITY can be measured SPECTROPHOTOMETER
Without:
Concentrations

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11
Q 
At which value can you say that the beta-caroten concentration is:
- Weak
- Medium
- Good
When the supply is?.....
A
  • Weak: <2 micomol/L
  • Medium: 2-5,6 micromol/L
  • Good: 5,6-9,3 micromol/L
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12
Q

When determine B-carrotene in BP, name 2 important materials needed (substances)?

A

Ethanol

Petrolether

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13
Q

Where is VIT A absorbed?

A

From the intestine –> Gets into the LIVER by blood in form of RETINYLESTER

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14
Q

Where can VIT A be stored?

A

In LIVER

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15
Q

What is VIT A level proportional to?

A

VIT A level is proportional to the vitamin supply of the animal

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16
Q

Vitamin A from the liver can be determined by?….

A

Carr Price´s Reaction

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17
Q

What is the principle of the Carr Price´s Reaction?

A

Vit A dissolves in chloroform
- Blue color with antimony trichloride (SbCl3)

The reaction consist of the insoluble compound SbCl3 + Water
–> Not suitable -> Water has to be drawn off

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18
Q

Name 4 importaint substances when determining VIT A in liver?

Study These Flashcards
A
  • Na2SO4 (in riboflavin detection Na2S2O4)
  • Chloroform
  • Acetic acid anhydride
  • Chloroform saturated w/ SbCl3
    (light+water sensitive)
19
Q

When observating the determination of VIT a in the liver, what are the colors?

Study These Flashcards
A

Blue –> Purple

20
Q

What kind of vitamin is THIAMINE?

21
Q

When determining THIAMINE (B1), what is the general about THIAMINE?

Study These Flashcards
A 
- It expresses its biological effect in the organism as:
Thiamine pyrophosphate (TPP)
  • It is the coenzyme of the oxidative decarboxylation of alpha-keto-acids
22
Q

What are the most important reaction of oxidative decarboxylation of alpha-keto-acids (THIAMINE, B1)

Study These Flashcards
A

Pyruvate –> Acetyl CoA

alpha-ketoglutarate—> Succinyl CoA

23
Q

What is the principle of detection of THIAMINE (b1)?

Study These Flashcards
A
  • In alkaline mileu = Thiamine transferred into THIOCHROME

- This compound shows BLUE fluorescence in UV-Light!

24
Q

When determining THIAMINE (B1), which 5 compound is really important?

Study These Flashcards
A
  • Vitamin B1 injection
  • NaOH
  • K3(Fe(CN)6)
  • I-butanol
  • UV-LAMP
25
What is general about Riboflavin?
- Vitamin B2 - Prosthetic group of several enzymes in the class of OXIDO-REDUCTASES is produced from RIBOFLAVIN - Ribaflavin are able to transport oxygen.
26
What is produced when the coenzyme can pass the hydrogen directly to the oxygen of the air?
Hydrogen perixide is produced or An enzyme of the respiratory chain: - Coenzyme Q
27
The oxidized form of riboflavin shows which color?
GREEN flouressence in UV light Redused form= Nothing happens
28
When determining Riboflavin (B2), name 3 important materials(substances) needed.
Neovit B complex injection Na2SO2O4 (almost as VIT a:Na2SO4) UV lamp (black background)
29
What is special about determination of Ascorbic Acid as a vitamin?
For animal organism: Vit C cannot be classified as strictly in the groups of vitamins - Because every species can synthesize it
30
What is the precursor of Ascorbic Acid (Vit C) syntheses?
The precursor of its synthesis is GLUCOSE
31
Determination of Ascorbic Ac (VIT C)? | What is the determination based on?
The determination is based on the reducing properties of Ascorbic acid (similar to Glucose)
32
Where is the ascorbic acid excreted?
In form of dehydro-acerbic acid in the URINE
33
When does domestic animals require Vitamin C supplement?
If they are affected my continuously STRESS | poultry
34
The ascorbic reduction potential can be examined with which reaction?
Fehlings treaction
35
Name some important materials needed when examining the reduction potential?
Ascorbic acid Fehlings regent I Fehlings regent II Hydrogen peroxide
36
The ascorbic reduction potential is examined by redox reaction, but how?
``` Dehydro acerbic acid (OX) = Green/blue Ascorbic Acid (RED) = Yellow = POSITIVE fehlingsreaction ``` Ascorb ac is able to donate 2H Dehydro-ascorbic acid is able to accept 2H
37
When examining ascorbic reduction potential with 2,6 dichlorphenol-indophenol - What is is?
2,6 dichlorphenol-indophenol = REDOX and a acid-base indicator at the same time. REDOX indicator= Colourfull when OX ACID-BASE indicator: Alkaline + Neutral = Blue Acidic mileu = RED Colour depends on PH
38
Name 4 importaint materials when examining the ascorbic reduction potential with 2,6 dichlorphenol-indophenol ?
Ascorbic Acid 2,6 dichlorphenol-indophenol Na2Co3 solution Acetic acid
39
The dehydro-ascorbic acid can be detected from where, and by using what?
From Urin | By using: 2,4-dinitro-phenylhydrazine
40
What is the principle of the reaction when using 2,4-dinitro-phenylhydrazine to detect the dehydro-ascorbic acid?
The excess of 2,4-dinitro-phenylhydrazine will react with the carbon molecules in position 1 and 2 of the dehydro-ascorbic acid.
41
The excess of 2,4-dinitro-phenylhydrazine will react with the carbon molecules in position 1 and 2 of the dehydro-ascorbic acid. What is produced?
Ascorbic acid and Osazone is produced
42
When Ascorbic acid and Osazone is produced, in which substance is it soluble in? And what will happen if you put the products in this substance?
Soluble in Sulphuric acid | ORANGE-RED color
43
The dehydro-ascorbic acid is detected from where? And by what?
From urin | Using: 2,4-dinitro-phenylhydrazine
44
When detecting dehydro-ascorbic acid, what materials are essential?
``` Urine Trichloracetic acid 2,4-dinitro-phenylhydrazine Thiocarbamid Sulphuric acid Active carbon powder ```

Biochemistry 2 (7 decks)

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