Removing parentheses around 2 elements in a list

Question

I have a list:

lst = [('1','one'),('2','two'),('3','three')]

I would like to remove the parentheses so that it becomes:

lst = ['1','one','2','two','3','three']

I tried:

lst = [j[0] for j in lst]

output:

lst = ['1','2','3']

can't figure out how to get the other elements in the list.