the use of essential and non-essential sentences
You use "which" if it is something nonessential to the sentence, and you use "that" when it is essential. Anything with a "which" should be set off by commas, but anything with a "that" should not. Examples: The dinner, which was quite tasty, was not very long. The dinner that we had at Wendy's was not very elegant.
Not essential., A thing not essential.
essential means it is very important and nonessential means that it isn't important.
Glycine is a non-essential amino acid
WHO ARE NON-ESSENTIAL WORKERS
non- as in nonessential.
some are made in the body (essential) and some are not (nonessential)
The non-essential subordinate clause is marked off by two commas, which act as a pair of parentheses. 'My cousin is a doctor' (independent clause). 'My cousin, who lives in Manchester, is a doctor' (non-essential subordinate clause; the information 'who lives in Manchester' is merely descriptive). 'My cousin who lives in Manchester is a doctor' (essential subordinate clause; the information 'who lives in Manchester' distinguishes this cousin from my other cousins who live elsewhere, therefore there are no commas).
Of the 20 amino acids, 10 must be taken in from an outside source; these are called nonessential amino acids.============================================================Actually its the other way round, amino acids that the human body can't manufacture are called essential amino acids. Non-essential amino acids are able to be produced by the body. Of the 20 amino acids that our bodies use, the adult body is able to manufacture 12For more information, check the link below
An essential mineral
The types of punctuation used for setting apart nonessential appositive phrases are commas. When set apart using commas, these phrases can be easily removed without changing the meanings of sentences.