Carbohydrates, fats, and proteins are made of carbon, hydrogen, and oxygen atoms.

Larger molecules are made of smaller ones:

Iodine Sloution: if iodine solution is added to starch it turns dark blue

Benedict's Solution: If glucose/sugar is heated with Benedict's the solution will turn clear blue, cloudy green, yellow then red. this is how you know its sugar.

Biuret Test: if you add dilute sodium hydroxie and copper sulfate to albumen(egg white protein) it will turn purple/violet to indicate proteins.

Ethanol Emulsion Test: add oil to ethanol and shake them together. If a white cloudy solution forms, this shows a positive test fro fats and oils.

DCPIP (Dichlorophenolindophenol): if you add lemon juice to DCPIP(blue dye) it will go clear immediately showing that there is a lot of Vitamin C in it.

Every type of protein has a different is arranged in a different sequence. It takes up a certain shape. This is a result of cross-linkages between amino acids that are not neighbours.

A DNA molecules is made of chains of nucleotides formed into two strands. they spiral around and create a helix shape

Nucleotides: 5-carbon sugar molecule joined to a phosphate group and an organic base.

The organic bases are paired together: Adenine(A) with Thymine(T); Cytosine(C) with Guanine(G)