Science Experiments : Food Test With Student In Laboratory

The human body needs different amounts of nutrients. Some are needed in large quantities (macronutrients), namely carbohydrates, proteins, and fats. There is also needed in small amounts, namely minerals and vitamins.
Macronutrients needed by human:

Carbohydrates

A carbohydrate is a biological molecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water). Source

Carbohydrates are formed in the process of photosynthesis by green plants of leaves. Carbohydrates include: sugar, flour, and cellulose. According to molecular size, carbohydrates are divided into the following groups: monosaccharides, including glucose, fructose, and galactose.

Each glucose molecule contains 38 ATP (adenosine triphosphate). Carbohydrate metabolism is influenced by certain enzymes and hormones. The carbohydrate function is as follows:

• As a producer of calories (1 gram = 4.1 calories)
• Formation of other organic compounds such as fat and protein
• Maintain the balance of acid-base in the body

Fat

Fat is one of the three main macronutrients, along with carbohydrate and protein. Fats, also known as triglycerides, are esters of three fatty acid chains and the alcohol glycerol. Source

Fat is composed of elements C, H, and O which are compounds. Fat consists of fatty acids and glycerol. In one fat molecule there is one molecule of glycerol and three fatty acid molecules.

Source of fat is divided into two kinds, namely animal and vegetable.
Fat is not soluble in water but soluble in ether, benzene, and chloroform. Fat consists of 2 components, namely fatty acids and glycerol. Every 3 fatty acid molecules bind to glycerol molecules form triglycerides. Fatty acids made by the body are called nonessential fatty acids, while fatty acids derived from foods are called essential fatty acids.

Protein

Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, and transporting molecules from one location to another. Source

Protein is a compound consisting of elements C, H, O, N, and sometimes there are elements of P and S. The protein molecule is composed of a number of amino acids as substances from the base.

There are some amino acids that can not be formed by our body, so it must be obtained from our daily food. Amino acids are called the essential amino acids, amounting to 8, namely: lisineleusin, isoleucine, threonine, methionine, valine, phenylalanine, and tryptophan.

Proteins are chemically digested into amino acids which are then absorbed into fine walls. These amino acids enter the blood vessels and are transported to the cells of the body.

Aim of Experiments:

Given a particular type of food, students can determine the food content through food test. Food test activity aims to determine what content is contained in a food.

Tools Needed :

• 8 test tubes
• Reaction tube shelf
• Pipette drops
• Spiritus burner
• Three legs
• An egg white solution of 5 ml
• 250 ml glasses
• Measuring cup

Materials Needed :

• Fehling solution A + B
• Lugol solution
• Biuret solution
• 5 ml starch flour solution
• 5 ml glucose solution

Procedure:

• Work in groups in this activity.
• Prepare the ingredients you've brought from home!
• Test food just like the steps on the table!
  
  
  

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Discussion

1. A food that is spilled with lugol and shows a change in color to dark blue signifies that the ingredients contain starch
2. A food that is served with benedict is then heated and indicates a change of color to a brick red indicating that the food contains glucose
3. An ingredient dripped with a biuret and indicating a change of color to purple indicates the food contains a protein

Conclusion

Foods containing protein when dropped with a biuret solution will turn the wana into purple.
If food is streaked with lugol solution will change color to purple to blackish then the ingredients contain starch.

If the ingredients are dropped the A + B fehling solution and then heated will change color to orange / orange then the food contains glucose.

Sources :

Carbohydrate

Fat

Protein

Organic-compounds

Macam zat tubuh

Best regard @draw-art