3.5 transcription and translation by arielle lafuente

vocabulary list:  RNA (messenger and transfer)  DNA  Transcription  Translation  Polypeptide  Codons  Anticodons  Ribosome  Adenine, guanine, thymine, cytosine, uracil  Degenerate  Universal

3.5.1 compare the structure of RNA and DNA DNA has: -bases: adenine, thymine, guanine, cytosine -sugar: deoxyribose -strand: double helix RNA has: -bases: adenine, guanine, cytosine and uracil replaces thymine - sugar: ribose (it has an oxygen bonded to it -strand: single strand

3.5.2 outline DNA transcription in terms of the formation of an RNA strand complementary to the DNA strand by RNA polymerase As the DNA uncoils two strands separate and free RNA nucleotides, the RNA polymerase, assemble themselves according to one template of the DNA strand. When they link together they form RNA. The DNA double helix rewinds and reforms as the mRNA separates from the DNA.

3.5.3 describe the genetic code in terms of codons composed of triplets of bases The genetic code is a triplet code- three bases code for one amino acid. Three bases grouped together becomes a codon. - the code is degenerate, meaning that 2+ codons can code for the same amino acid - the code is universal, meaning that all living organisms use the same code, including viruses

3.5.4 explain the process of translation, leading to polypeptide formation The mRNA binds a ribosome which the tRNA binds to as well. The the tRNA which is the molecule depicted to the right with a codon at the bottom and an amino acid at the top. As the anticodon of tRNA matches up to the mRNA codon the amino acids link together through peptide linkage forming a polypeptide chain as the process is repeated.

3.5.5 discuss the relationship between one gene and one polypeptide Polypeptides are long chains of amino acids. There are 20 different amino acids that can form part of a polypeptide. To make one particular polypeptide, amino acids must be linked up in a precise sequence. Genes store the information needed for making polypeptides. The information is stored in a a coded from. The sequence of bases in a gene codes for the sequence of amino acids in a polypeptide. The information in the gene is decoded during the making of the polypeptide. It was originally believed tat one gene would invariably code for one polypeptide, but many exceptions have been discovered.

more sources: Refer to pages for a much more detailed account of section 3.5 Look at the many drawings depicting all the processes and if you still need help you can refer to the text. go to: m/watch?v=41_Ne5 mS2ls&feature=ema ilt To see a very thorough and detailed video about all of these processes.