Genotypes (Dihybrid Crosses Question)?

we come now to the pi�ce de r�sistance: ribosome. universal ribosome. ribosomes link the genotype to the phenotype. ribosomes are at one and the same time essential and complicated. what does it mean, the ribosome, our universe? it means the every single cell has ribosomes. or: there are no cells that lack them. ribosomes are essential since they alone are capable of crafting protein. ribosome. and without protein, there there can be no life. ribosome. how do ribosomes link the genotype to the phenotype? gene expression requires transcription of information stored in the dna of genes into rna. these rna transcripts of genes are called messenger rna. each messenger rna, like the gene of which it is a transcript, encodes a sequence of amino acides in a protein. the messenger rna are colinear with the dna in gene. messenger rna binds to a ribosome. ribosome stitches together a sequence of amino acids according to the sequence encrypted in the messenger rna. the stitching is done just like a sewing machine might do, and with great speed. ribosome makes about 30 peptide bonds per second. peptide bonds link amino acids in protein. the are in human cells about a million ribosomes. ribosomes are complicated. they have two separte subunits, composed in all of three or four molecules of rna and 50 to 90 proteins, depending on the species. in human cells the ribosomes have four molecules of rna and 79 protein. what are the problems concerning ribosome that entertain us? with respect to their structure we would like to know the exact coordinates of each of the rna and protein molecules, and eventually of each of the atoms in the molecule. with regard to function, we hope to use this structure to provide a coherent molecular account of how the ribosome participates in the synthesis of a protein. there are two important outstanding function related problems. the first is a chemical detail of how a peptide bond is made, that is, how the amino acids are linked. the second is how chemical energy is transduced to give mechanical movement, or translocated. as each amino acid is added to the growing nascent protein chain, the messenger rna and the ribosome must move one codon with respect to each other, so that the next codon can be read or translated. ribosome.