Chapter 17 Lecture Notes
Chapter 17 Lecture Notes BIO 120
Popular in General Biology
Popular in Biological Sciences
This 4 page Class Notes was uploaded by Haleigh Siple on Friday November 20, 2015. The Class Notes belongs to BIO 120 at Grand Valley State University taught by Rybczynski in Summer 2015. Since its upload, it has received 36 views. For similar materials see General Biology in Biological Sciences at Grand Valley State University.
Reviews for Chapter 17 Lecture Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 11/20/15
Bio 120 Lecture Notes Nov 16th Bio 120 Lecture Notes Chapter 17 Gene Expression Albino Corn lacks chlorophyll due to a mutation A protein responsible for chlorophyll synthesis is not present in the mutated genetic material and subsequently that plant lacks the chlorophyll pigment DNA 9 RNA 9 Protein 9 Trait Flow of Genetic Info Protein Synthesis occurs over two stages 1 Transcription DNA 9 RNA 2 Translation RNA 9 Protein Genes specify proteins through transcription and translation Some RNA molecules are transcribed but not translated and therefore not expressed Transcription occurs in the Nucleus and Translation occurs in the cytoplasm Ribosomes function in protein synthesis Smooth ER 9 Lipid synthesis Rough ER 9 Polypeptide synthesis Prokaryotes lack a nucleus and there is no separation between transcription and translation they occur almost simultaneously In eukaryotes transcription and translation are separated by nuclear envelope Primary Transcript premRNA introns cut out during RNA processing 9 mRNA Triplet codes 20 amino acids altogether 3 base pairs that code for an amino acid The template strand is transcribed from original DNA mRNA is Complementary to template strand Antiparallel Synthesized and read 5 9 3 new nucleotides only added at 3 end Codons 3 nucleotide sequence on mRNA molecule that codes for a particular amino acid Not all amino acids are proteinogenic protein producing R Groups in Amino Acids are important for protein function and structure Bio 120 Lecture Notes Nov 16th Complementary Strand Example 3 TACCGTGAT 5 3 ATGGCACTA 5 Template Strand Example 3 TACCGTGAT 5 3 AUGGCACUA 5 RNA polymerase enzyme that adds more nucleotides Promoter Section of DNA DNA sequence where RNA polymerase binds and initiates transcription Components of Transcription Initiation RNA polymerase attaches Elongation mRNA grows Termination RNA polymerase lets go of DNA molecule Promoter TATA box serves as the recognition site for RNA polymerase to bind Transcription factors molecules that help RNA polymerase to bind to DNA provide regulation Eukaryotic Cells modify RNA after transcription Nuclear enzymes alter the primary transcript Alteration at mRNA end 5 cap and 3 polyA tail Export from nucleus into cytoplasm Protection degradation hydrolytic enzymes Ribosome binding Split Genes and RNA splicing Intron intervene between coding section not expressed Exon expressed genes Spliceosomes cut out introns connects the exons together Introns allow for exibility and variation in an organisms genome Bio 120 Lecture Notes Nov 16th Some sections of DNA can code for multiple products therefore one gene different polypeptides Protein Domains discrete structural and function regions active site attachment to the membrane Exon Shuf ing provides genetic variation Transfer RNA brings amino acids to ribosomes Anticodon Complementary Example Codon UUU Anticodon AAA Structure and Function of Transfer RNA Single Strand L Shape Held together With hydrogen bonds Aminoacyl tRNA synthetase joins amino acids to correct tRNA covalent Ribosomes are made up of large and small subunits Ribosomal RNA rRNA and proteins Nucleolus produces ribosomal subunits rRNA synthesis in nucleus Proteins imported Eukaryotic ribosomes are larger differ in molecular composition Some Antibiotics inactivate prokaryotes by impairing tRNA Three binding Sites for tRNA P Site peptide bonding site for growing polypeptide A Site amino acid bonding site E Site exit Building a polypeptide initiation elongation and termination Termination of translation stop codons Completing and targeting the functional protein during synthesis polypeptide coils and folds spontaneously alter 3D shape Specific Cellular Sites Signal Peptides cellular zip codes Cytosol Bio 120 Lecture Notes Nov 16th Endomembrane System embedded Secretion lumen Polyribosomes several ribosomes translate mRNA simultaneously The Cell creates copies of polypeptides quickly Coupled Transcription and Translation in prokaryotes efficient Mutations of l or more nucleotides can affect protein structure and function Changes in one base pair of a gene Substitutions Replacement of nucleotide and its partner No effect Missense new amino acid Nonsense code for an early stop Insertions and deletions additions or losses of nucleotide pairs Frameshift mutations change downstream triplets Insertion and deletions are the most damaging New Mutations and Mutagens 9 cause spontaneous mutation DNA replication recombination and repair Physical and chemical agents Xrays UV Lights Tobacco alcohol Mutagenic carcinogenic cancer causing
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'