The nucleus is the 'command center' of the cell ·nucleus contains DNA ·DNA contains genes ·Genes contain instructions for making proteins ·Proteins (enzymes) carry out biochemical reactions

Transcription and Translation are the two stages of protein synthesis (process of the cell creating new proteins) ·Involves both DNA and RNA

DNA RNA contains a 5-carbon sugar 5-carbon sugar is deoxyribose 5-carbon sugar is ribose each nucleotide has one of 4 nitrogenous bases nitrogenous bases are cytosine, guanine, adenine, thymine nitrogenous bases are cytosine, guanine, adenine, uracil double stranded molecule (usually) single-stranded molecule

Transcription ·Occurs in the nucleus ·Helicase separates the DNA strands ·RNA polymerase uses one strand of DNA as a template for an RNA strand to be created -using complimentary base pairing (with U instead of T)

Transcription bubble

3 types of RNA made this way: ·messenger RNA (mRNA) ·The purpose of this is so that RNA can travel out of the nucleus to the ribosome (DNA is too big to leave) 3 types of RNA made this way: ·messenger RNA (mRNA) ·ribosomal RNA (rRNA) ·transfer RNA (tRNA)

Genetic Code is the genetic information that is stored in codons ·Codon = triplet of 3 bases ·there are 64 possible codons - 3 are stop codons - 61 code for the 20 amino acids ·therefore, the genetic code is redundant

Translation ·messenger RNA (mRNA) created by transcription leaves the nucleus and travels to the Endoplasmic reticulum or cytoplasm two subunits of ribosomes latch on ·Ribosome slides over mRNA and “reads” it one codon at a time

·For each codon sequence, a molecule called transfer RNA (tRNA) briefly attaches its complementary anticodon to the codon.

·Each tRNA molecule carries one specific amino acid based upon it’s particular anticodon ·When the tRNA anticodon attaches to the mRNA codon it releases it’s amino acid ·As each codon is read a different tRNA will drop off it’s amino acid ·These amino acids peptide bond to each other to form a polypeptide chain (basic protein structure)

Protein Synthesis Animation

·Each protein synthesized in the body originates from one particular section of DNA on a chromosome ·This section, called a gene, can be several hundred to several thousand base pairs long

College prep book: p 336-341 1st: Read and add to notes ·especially introns, exons, and One gene- One enzyme 2nd: p341 #1-6 on separate page