Protein Synthesis:
Consists of transcription within the nucleus, then translation outside of the nucleus (can occur on the rough ER or in the cytoplasm using ribosomes). The DNA (unwound chromosomes) contain genes that code for specific proteins using the four different nitrogenous bases, A T C G. In transcription, RNA polymerase (a protein) binds to a specific gene sequence on DNA. The binding is caused by signals within the cells or outside the cell that basically say "we need more of this right now" (a good example is lactase which tells the cell it needs to make proteins that digest lactose in the presence of lactase, an enzyme). It runs alonga segment of DNA and makes an RNA copy, called mRNA (messenger). The messenger RNA is the spliced and "introns", extra bits of coding on the mRNA, are removed. the mRNA then moves outside the nucleus into the rough ER (or it could work in the cytoplasm using free ribosomes), where it binds to two ribosome subunits (one is called large, and the other is small. you can guess why). The mRNA then goes through Translation, where another type of RNA called tRNA (transfer) reads the mRNA 3 letters at a time, and attaches the appropriate amino acid to a chain. A triplet of letters each code for a different amino acid, and a chain of amino acids makes a protein.
The whole process is only a bit more complicated, with names of certain parts of the RNA, but this is the basic jist of it.
tl;dr... chromosomes unwind during interphase, DNA has genes that code for a chain of amino acids which creates a protein. Two main processes: transcription in the nucleus where the DNA sequence is copied to mRNA, then translation outside of the nucleus where the mRNA is read in a ribosome and an amino acid chain is assembled
