the nucleus is a large dark sphere housing our genes which house our hereditary characteristics most cells have one red blood cells don't have one some have multiples like muscles because as they grow in length they are fused smaller muscle cells together so the nucleus stays behind so they have multiple ones when they're grown up a cell must have at least one of them to be able to divide two elementary membranes filled with pores create a boundary to the cytoplasm the nucleolus on the inside of the nucleus is a factory for ribosomal RNA which basically our ribosomes we'll talk about those in a little bit and this brings us to the chromosomes and our genes chromosomes are the carriers of our hereditary characteristics one gene contains information to make one protein the chromosomes therefore our cookbook for proteins we have 46 chromosomes two sets of twenty three twenty three materials from the mom and 23 Paterno's from the dad this makes us the diploid haploids in contrast have only one set not two sets of chromosomes we humans have 30 to 40,000 genes packed in a DNA double helix of about two meters in length that's about two yards that's a lot this needs to be very well-organized otherwise we have a mess so this long strand of double helix will coil around histone proteins they wrap particularly tightly when we are doing mitosis so what you see then are these large X's and where they cross in the middle is called a centromere if we need to make protein they are called the part of the double helix cookbooks that holds that specific gene let's talk more about how the genetic code works this is to set up DNA is two nucleotide strands connected by hydrogen bonds into a double helix three nucleotides in a row called for one amino acid we call that a triplet or a codon chains of amino acids then make our proteins how do we get them made from DNA well we'll have to first find the right gene then we unwind and unzip the double helix at that point now since the DNA will not leave the nucleus because that would be too dangerous we make a copy of the nucleotide strands that codes for the specific protein this strand now is then called an mRNA it leaves the nucleus feeds into the ribosomes where the nucleotides are decoded and proper amino acids are brought and attached to one another let me explain RNA a bit more it is similar to DNA except it has only one strand it has a different sugar and it uses two nucleotide uracil instead of thymine I know it's complicated that's why we're doing it this way we have three types of related structures that we call RNA messenger RNA or mRNA is the copy of DNA ribosomal RNA or our RNA is the part of the ribosomes that is reading the nucleotide codons and transfer RNA or tRNA brings the proper free-floating amino acid from the cytoplasm and helps attach it to the growing polypeptide chain let's do it again because we have two more new terms that we need to feed in here so first the on coil and on Sep the double helix at the appropriate chain then we copy that using RNA polymerase enzyme this process results in the mrna strand and is called transcription that's a new term transcription the mRNA then leaves the nucleus through a pore and feeds through a ribosome vertie RNA brings the proper amino acids and attaches them in the proper sequence this process is called translation I know it's a lot of terms then transcribing we transfer the information to a different medium from DNA to mRNA in translation we change the language so to speak from a genetic material to a protein that's how I remember it maybe it helps