BIOL 2050 1st EditionFinal Exam Study Guide Lectures: 22-31Lecture 22 (April 3rd)DNAWhat discoveries led to the current idea of DNA? What did we learn about the structure of DNA from these discoveries?- T.H. Morgan’s group showed that genes are located on chromosomes- Frederick Griffith discovered the genetic role of DNAo Used transformation method- Hershey and Chase showed that DNA is the genetic material of viruses- Chargaff discovered that DNA composition varies from one species to the next and in any species the number of A and T bases are equal and the number of G and C bases areequal.- Maurice Wilkins and Rosalind Franklin used X-ray crystallography to identify the molecular structure of the double stranded helix.- Watson and Crick constructed a model of the double helix.o Antiparallel backboneso Purines paired with pyrimidines What is involved in the process of replication?Replication: the parent molecule unwinds and two new daughter strands are built based on the base-pairing rules.Process:- Replication starts at the origin of replicationo Initiationo Elongationo Termination - Replication proceeds in both directions- Helicases untwist the double helix- Topoisomerase corrects overwinding ahead of replication fork.- DNA polymerase catalyzes the elongation of new DNA at a replication forkLecture 23 (April 8th)What are the basic components of DNA replication?- Topoisomerase- Helicases- Primase- Single-strand binding proteins - RNA Primer- Leading Strand- Lagging Strand- DNA Polymerase - Okazaki Fragments - DNA LigaseLecture 24 (April 10th)Describe the process of a gene becoming a protein. Central Dogma:DNA-> RNA-> Protein1. Transcriptiona. Produces mRNA2. Translation: synthesis of a polypeptide using the information from mRNAa. Occurs at ribosomesb. Triplet Codon: a series of nonoverlapping, three nucleotide words that are transcribed into three-nucleotide words of mRNA.c. These are then translated into the amino acids that make up a protein- RNA Splicing: removes introns and joins exons creating an mRNA molecule with a continuous coding sequence.Lecture 25 (April 13th)What are the different types of mutations and what are their impacts on the genetic code?Mutations: genetic changes in the DNA of a cell- Point: changes in a single nucleotide pair of a geneo Consequences vary- Nucleotide-pair substitution- Silent Mutation: no observable effect on the phenotype- Missense Mutation: change one amino acid to another- Nonsense Mutations: causes translation to be terminated prematurely by changing a codon to a stop codon.- Insertions and Deletionso Frameshift Mutations: occurs whenever the number of nucleotides inserted or deleted is not a multiple of three.Lecture 26 (April 15th)What are the major components of Translation?Translation- tRNA helps translate an mRNA message into a protein- Ribosomes facilitate specific coupling of tRNA anitcodons with mRNA codons in protein synthesis.- Polypeptideo Initiationo Elongationo Termination- Polyribosomes are a number of riobosomes that translate mRNA simultaneously.- Functional Protein:o Formed after polypeptide chains are modified and then coil and fold into a three-dimensional shapeLecture 27 (April 17th)What are the differences of gene expression between eukaryotes and bacteria?Bacteria:- Operon modelo Turning a gene on and off Promoter: on switch Repressor: off switch- Prevents gene transcription by binding to the operator and blocking RNA polymerase.- Negative Gene Regulationo A repressible operon is one that is usually on and binding of a repressor to the operator shuts off transcriptiono Tryptophan Operon- Inducible Operon: usually off and an inducer inactivates the repressor and turns transcription ono Lac operonEukaryotes- Signal comes into the nucleus and activates gene transcription and RNA processing- Chemical modifications to histones and DNA of chromatin influence chromatin structure and gene expression.- Chromatin modifying enzymes provide initial control of gene expression by making a region of DNA more or less able to bind to transcription machinery.Lecture 28 (April 22nd)What are the different types of reproduction?Asexual: the generation of new individuals without the fusion of egg and sperm.- Fission- Budding- ParthenogenesisSexual: the fusion of haploid gametes that forms a diploid cell.- Zygote- Hermaphroditism: each individual has both male and female reproductive systems- Fertilization Lecture 29 (April 24th)What are the basic hormones involved in the ovarian cycle and how do they interact?Hormones:- GnRH: released by the hypothalamus and stimulates the anterior pituitary to release FSH and LH.- FSH: (Follicle-stimulating hormone) stimulates follicle growth- LH: aids in the stimulation of follicle growth- Estradoil and Progesterone: as levels of these hormones rise, a negative feedbacksystem on the hypothalamus and pituitary stops the release of FSH and LH.What are the two different reproductive cycles that mammals have?Mentrual Cycle: indicate a change in the uterus and typically is a 28-day cycleEstrous Cycle: a reproductive cycle characteristic of female mammals except humans and certain primates, in which the nonpregnant endometrium is reabsorbed rather than shed and sexual response occurs only during mid-cycle at estrus.Lecture 30 (April 27th)What are the parts of the body that are involved in fertilization? How are they involved?Female Reproductive System:- Paired ovaries: eggs are released- Fallopian Tubes (Oviducts): draw egg down towards uterus- Uterus: where fetus developsMale Reproductive System:- Testes: sperm is madeo About 50 sperm reach an egg but only one fertilizeso Swim through female reproductive tract- Vas Deferens: carries sperm from testes to urethra and then is ejaculated out of the penis.Lecture 31 (April 29th)What are characteristics of the basic structure of DNA?Structure:- Double Helix- Antiparallel - During replication:o Lagging strando Leading strando SemiconservativeWhat are the main components of the process of a gene becoming a protein?Transcription- Polymerase binds to promoter- Strands separate- Elongation- TerminationModifications:- Splicing introns- 5’ cap- Poly A tailTranslation- A site- P site- E site- Polypeptide is formed- tRNALecture 32 (May 1st)What are some ways that bacteria is different from eukaryotic cells in terms of gene expression?Bacteria:- Use the operon modelo Use positive and negative feedback to control gene expression- Protect DNA from restriction