There are twenty different types of which join together in differing sequences and numbers to form different proteins.

There are of AMINO ACIDS which join together
Amino acids are the building units of protein. There are basically twenty different types of amino acids which are divided into two classes of essential and non essential amino acids based on their requirements in human nutrition. These amino acids joined together in different manner to form different types of proteins.

True statement gravity force is more on bigger mass, less on smaller mass.all mass fall on planet with same acceleration and speeds