What enzyme is used to open up the dna molecule before replication can take place

Glycogen is an energy-storage molecule in humans. a hormone that is called insulin controls the storage of glycogen in the liver. insulin is made up of amino acids.

Use the phylogenetic tree to the right to determine which statement below is true. organisms a and f are not related. organism e is more closely related to organism b than organism f. organisms c and d are more closely related than organisms a and b. phylogenetic trees

What kinds of molecules can pass through the cell membrane without any problem?