Study Guide Ap Bio Ch 16-18

Study guide for Ch 16-18 Chapter 16 Alfred Hershey and Martha chase answered the inquiry whether protein or desoxyribonucleic acid was the brokertic material by using B proceedingeriophages (viruses that pollute bacteria). o Bacteriaphages were good for the experiment because they only contain 2 constitutional compounds, deoxyribonucleic acid and protein. James Watson and Francis Crick were the first to solve the structure (structure=function) of desoxyribonucleic acid. roentgenogram crystallography( process used to visualize molecules in 3-D. desoxyribonucleic acid is a forficate helix- structure The nitrogenous bases of deoxyribonucleic acid argon( adenine (A), thymine (T), guanine (G), and hundred (C). The 2 desolates (the leading and the lag mountain range) are antiparallel. o The leading shore goes in direction 5 to 3. o Lagging strand goes 3 to 5. Takes longer to replicate cause its create in fragments. careen from the book(know these enzymes for replication DNA polymerase, ligase, helicase, and topoisomerase. Know this enzyme for agreement(the role of ribonucleic acid polymerase. Replication(making DNA from already existing DNA strand. DNA replication is semiconservative (1/2 of rakehellal DNA and the other ? is from new DNA strand). This is used by humans A group of enzymes called DNA polymerases catalyzes the elongation of new DNA at replication fork. The overall direction of DNA replication goes from the origin to the fork. o DNA polymerase adds cornerstones to the growing chain whizz by one working in a 5 to 3 (DNA have strand (new) or ribonucleic acid polymerase go 5(3 in the build strand). Parent strand DNA and ribonucleic acid polymerase is 3 to 5. o DNA polymerase matches adenine with thymine and guanine with cytosine o The lagging strand is synthesized in separate pieces called Okazaki fragments (which segments in 3(5), which are whence sealed together by DNA Ligase.Forming a continuous DNA strand. Many factors in repl ication o Base pairing in DNA replication( A=T/ G=C. o Mismatch fix(special repair enzymes fix incorrectly paired nucleotides o Nucleotide excision repair. Tip****(know the difference between replication (DNA to DNA), organization (DNA to ribonucleic acid), and reading (ribonucleic acid to protein). In eucaryotic booths, DNA and protein are packed together as chromatin. o Heterochromatin(very condensed chromatin. o Euchromatin(loosely condensed chromatin. Telemer region(small fragment of DNA that is lost during replication due to enzymes inability to attach the fragment on to the ending of the DNA helix. (This is our biological clock). Chapter 17 Gene grammatical construction(the process by which DNA directs the synthesis of proteins (or sometimes RNA). organization= DNA(RNA o Takes place in the nucleus in eukaryotic cells. messenger RNA ( template RNA) produced during transcription. It carries the genetic message of DNA to the protein making machinery of the cell in the cytoplasm, ie the ribosome. The mRNA triplets are called codons (a codon is a mRNA triplet). o mRNA is read codon by codon. ? Start codons and nail codons are used in the build strand the protein coding segment is between the start codon and stop codon in the build strand. They are written in the 5 to 3 direction. More than one codon enciphers for each of the 20 amino acids. Genetic code includes 64 codons (4 x 4 x 4). o The group must(prenominal) be read in the correct groupings in order for translation to be successful o 3 codons act as manifestation exterminators (UAA, UAG, UGA) o AUG always has to be start codon. RNA polymerase(enzyme that separates the 2 DNA strands and connects the RNA nucleotides as they base-pair along the DNA template strand. o RNA pol. Can add RNA nucleotides only to the 3 end of the strand. regain uracil replaces thymine when base pairing to adenine. ==difference betw DNA and RNA. o The DNA sequence at which RNA pol. Attaches is called the P romoter. o The DNA sequence that signals the end of transcription= Terminator. placement unit(the entire stretch of DNA that is transcribed into an RNA molecule. 3 main stages of transcription from the book. Initiation (RNA polymerase that transcribes mRNA cannot bind to the takeoff booster region with bug out supporting help from proteins known as transcription factors. transcription factors assist the binding of RNA polymerase to the promoter, thus the initiation of transcription) Notes o elongation (RNA polymerase moves along the DNA, continuing to untwist the double helix. RNA nucleotides are continually added to the 3 end. As this happens, the double helix re- wee-wees. Notes Termination (RNA polymerase transcribes a terminator sequence in the DNA, the RNA transcript is released, and the polymerase detaches. There a rival of key post-transcriptional modifications to RNA( the addition of a 5 cap and the addition of a poly A Tail (3). RNA splicing also takes place in euka ryotic cells. Large portions of the newly synthesized RNA strand are removed. This is the upgrade strand. o The sections of the mRNA that are spliced out are called introns. o Sections that are spliced together by a spliceosome(exons. ? The new strand containing the exons is called the build strand, which runs in a direction of 5 to 3.Remember parent strand runs in 3 to 5. Small nuclear RNA (snRNA)( diarrheas a major(ip) role in catalyzing the excision of the introns and joining of exons. o Ribozyme is when RNA services a catalytic role. Translation o 2 additional guinea pigfaces of RNA play important roles in translation besides mRNA ? Transfer RNA ( tRNA) and ribosomal RNA (rRNA). tRNA functions in transferring amino acids from a pool of amino acids located in cytoplasm to a ribosome. These amino acids are co-ordinated into a growing polypeptide chain. At one end of a tRNA it loosely binds the amino acid, and at the other end it has a nucleotide triplet called an anticodo n (allows it to pair specifically with a complementary codon on the mRNA). rRNA complexes with proteins to form the 2 sub units that form ribosomes. o Translation can be divided into 3 steps ? Initiation, Elongation, and Termination (descriptions of these steps can be found on pg 129-130 I got lazy so fuck off) The polish guide goes into mutations on pg 130 but I think that youre better off reading the guide than reading my description. Chapter 18 In bacteria, genes are often clustered into units called operons. Operon consists of 3 parts o mover controls the access of RNA polymerase to the genes, its found within the promoter region. ? usually in on position. In a repressible operon. o Promoter where RNA polymerase attaches. o Genes of the operon the entire stretch of DNA required for all the enzymes produced by the operon. Regulatory Genes(produce repressor proteins that may bind to the floozie site. When a restrictive protein occupies the operator site, RNA pol. Is block ed from the genes of the operon. Repressible operon( normally on. It can be inhibited. This type of operon is normally anabolic. o The repressor protein produced by the regulative gene is inactive. o If the organic molecule being produced by the operon is provided to the cell, the molecule can act as a corepressor, and bind to the repressor protein(this activates it. ? The activated repressor protein binds to the operator site, shutting down the operon. The lac operon is inducible o Controls the production of B- galactosidase an enzyme that catalyzes the hydrolysis (break down) of lactose into glucose and galactose ?Inducible operon(gene expression B-galactosidase is stimulated by the presence of a co inducer, lactose. Turns the repressor gene switch off. o This is notes on gene expression on tryptophan. nigh stuff is from book. ? Inducible operon( normally off but can be activated. This type of operon is catabolic, breaking down food molecules for energy. The repressor protein produced by the regulatory gene is active. To turn the inducible operon on, a specific small molecule, called an inducer, binds to an inactivates the repressor protein.With the repressor out of the operator site, RNA polymerase can access the genes of the operon. o 2 regulatory mechanisms used to turn on lac operon ? Presence of lactose as co inducer ? Low amounts of glucose. These 2 are the only way for this nominate to work yo Differential gene expression in eukaryotic cell gene expression o The expression of different genes by cells with the like genome. Histone acetylation( acetyl groups are added to amino acids of histone proteins, thus making the chromatin slight tightly packed and encouraging transcription. DNA methylation( the addition of methyl groups to DNA it causes chromatin to condense, thus reducing gene expression. o With the help of phosphorylation bordering to a methylated amino acid, chromatin becomes loosened and thus encouraging transcription. Epigenic inheritance( the inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence. Transcription initiation is where DNA control elements that bind transcription factors are convolute in regulation. Control elements( multiple control elements(segments of non coding DNA that serve as binding sites for transcription factors that help regulate transcription. o This is essential for the precise regulation of gene expression in diff cell types. o Proximal and Distal control elements. ? Proximal control element has to be right next to promoter anything else is distal. Transcription factors( o Enhancer regions are bound to the promoter region by proteins called activators. o Some transcription factors function as repressors, others function as activators. Extra stuff TATA case is at the beginning of promoter region.