Biology
Illness in infants
Author
Cécile Bardel, Charles Baudelaire
Target Group
16-17 years old students
Brief Description
Illness in infants

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ILLNESS IN INFANTS 

Topic Handout (1/2)

Overview and research to carry out

A baby is taken to the emergency services. It is showing signs of diarrhoea, irregular passing of wind and vomiting since it started to eat baby food prepared with certain grains. The doctor thinks there is a possible malfunction of two enzymes normally present in a child’s digestive juices: salivary amylase and/or intestinal maltase. The accumulation of starch and/or maltose in the intestine would thus be the root cause of the observed problems.

 

The aim is to determine if the infant’s problems are the result of a malfunction with its salivary amylase and/or intestinal maltase enzymes. 

Resources

Document:

An enzyme is a protein acting as a biological catalyst.

 

The substrate of an enzyme is a molecule which, after binding to an enzyme’s active site, is transformed into one or several other products. 

Document :

 

Starch is a complex carbohydrate formed by linking together a large number of glucose molecules.

 

Amylase is an enzyme in the saliva which catalyses the breaking down of starch into maltose, a carbohydrate made up of two glucose molecules.

 

Maltase in an enzyme found in the intestine that catalyses the hydrolysis of maltose into glucose.

 

Glucose is the only molecule which can be digested by mucus in the intestine. 

Step 1: Plan an experiment to help to resolve the problem (10 minutes maximum)

Come up with a feasible experiment which would allow you to check if the infant’s problems are the result of a malfunction with its salivary amylase and/or intestinal maltase enzymes. 



ILLNESS IN INFANTS 

Topic Handout (2/2)

Step 2: Carry out the experiment to obtain exploitable data

Carry out the experiment on the digestion of starch to determine if the infant’s problems are the result

of a malfunction with its salivary amylase and/or intestinal maltase enzymes. 


Step 3: Process the data and present your findings

In the form of your choice, process and present the raw data so that you have the necessary information to respond to the problem. 


Step 4: Used the obtained results to respond to the problem and answer the question

Process the results to determine if the infant’s problems are the result of a malfunction with its salivary amylase and/or intestinal maltase enzymes. 




ILLNESS IN INFANTS 

Protocol Handout

Equipment available and procedure for using the equipment

Additional Materials :

 

Fehling’s solution is a blue chemical reagent which forms a brick-red precipitate in the presence of reducing sugars such as glucose, galactose, or maltose.

Iodine solution is a reactive orange solution which turns violet-blue in the presence of starch.

Equipment

 

- Solution of working a-amylase

- Solution of the child’s a-amylase

- A 1% starch solution

- 6 test tubes

- Test tube rack

- 6 2ml graduated pipettes

- 1 10ml graduated pipette

- Fehling’s solution and a pipette

- Iodine solution and a pipette

- Titration plate with at least 4 holes

- A pipette bulb to pipette

- 1 stopwatch

- 1 water bath maintained at 37°C

- 1 water bath maintained at 80°C.

- 2 thermometers

- Marker

- Gloves and safety goggles

To determine if the infant’s problems are the result of a malfunction with its salivary amylase and/or intestinal maltase enzymes.:

- Carry out the following experiments observing the correct experiment conditions.



SubstrateEnzyme solution 

Temperature

in °C

Tubes
Nature
Volume in ml
Nature
Volume in ml
AStarch Solution
10
working a-amylase 
2
37
BStarch Solution
10
a-amylase from the child
2
37

- Réaliser un test à la liqueur de Fehling et à l'eau iodée pour chacun des tubes à t=0 et t=10 minutes en respectant le principe suivant :


Mixture
Test conditions
1 ml of Fehling’s solution + 2 ml of solution to be tested
Water bath at 80°C for 3 minutes
Several drops of iodine solution + several drops of solution to be tested
Titration plate


Safety


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Handling precautions

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ILLNESS IN INFANTS 

SUPPLEMENTARY INFORMATION


       An in vitro digestion of the maltose has been carried out with a working maltase sample and a sample of maltase from the infant. The results

are given in the following table: 


Results of the digestion of maltose by a smaple of functional maltase and the child’s maltase





Maltose
Glucose


Beginning of the

digestion

End of the

digestion

Beginning of the

digestion

End of the

digestion


Functional maltase
+--+
Enzymes used
Infant’s maltase
+--+




ILLNESS IN INFANTS 

Lab sheet for the teacher

Matériel par élève :

- Solution of working a-amylase

- Solution of the infant’s a-amylase

- 1% Starch solutions

- 6 test tubes

- Test tube rack

- 6 2ml graduated pipettes

- 1 10 ml graduated pipette

- Fehling solution and a pipette

- Iodine solution and a pipette

- Titration plate with at least 4 holes

- A pipette bulb to pipette

- 1 stopwatch

- 1 water bath maintained at 37°C

- 1 water bath maintained at 80°C

- 2 thermometers

- Marker

- Gloves and safety goggles






ILLNESS IN INFANTS 

Expected result

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Related files

expected result for the experiment 188 KB
Illness in infants 676 KB
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