BIOL 1543 1st Edition Exam# 2 Study Guide Downloads: 8 – 11Download 8Nucleotide monomers are composed of sugar, phosphate, and a nitrogenous base- DNA and RNA are polymers of nucleotidesDNA has four kinds of nitrogenous bases1. Thymine (Py)2. Cytosine (Py)3. Adenine (Pu)4. Guanine (Pu)- The two types are Pyrimidines and PurinesHow do we know its DNA?- The sugar is deoxyribose- The nitrogenous bases are A, T, G, and CHow do we know its RNA?- The sugar is ribose- The base Uracil is used in place of ThymineDNA is a double stranded helix- With a sugar-phosphate backbone- Hydrogen bonds between bases hold the strands together- A pairs with T- G pairs with CReplication (aka duplication) The process of making two copies of a DNA strand- Complicated process because part of the DNA has to untwist- Happens very quickly and with few errors- There is a proofreading enzyme- There is a repair enzymeGenotype An organism’s genetic makeupPhenotype The characteristics we see; the manifestation of genetic informationGene A long line of nucleotides; a hereditary unit of informationGENES TO PROTEINS- The DNA of a gene is transcribed into RNA and then translated into the polypeptide- Two stages of expressing info in DNAo Transcription (DNARNA) Happens in the nucleus Produces genetic messages in the form of RNA Three Stages- Initiation- Elongation- Termination RNA that is used to make proteins is mRNA Messenger RNA carries the genetic message out of the nucleuso Translation (RNAProteins) Happens in the cytoplasm Genetic information written in codons is translated into amino acid sequences A ribosome attaches to mRNA tRNA translates the message into a polypeptideCodons triplets of bases that specify the amino acid sequence of a polypeptideMutations Something capable of causing genetic change- Ex. Radiation or Certain chemicals- Cause by 2 things:o Error in DNAo Mutagens- Has varying effects on the organism- 3 ways genes are altered:o Base Substitutiono Insertion of an extrao Base DeletionEryth RedCyte CellErythrocytes Red Blood CellsChromo ColoredSome BodyPhago EatDownload 9Viruses are genes packaged in proteins- A “phage” aka a Bacteriophageo Means in attacks bacteria2 Reproductive Cycles1. Lytic Cyclea. Phage DNA enters a lytic cycle inside a bacterium and then replicates, transcribes, and translates2. Lysogenic Cyclea. Phage DNA inserts into the host chromosome and is passed on to generations of daughter cellsb. 3 Possible Outcomes:i. Reproduces Asymptomatically ii. Bacteria starts behaving in a different manner, altering the host cell’s functioniii. Can convert to the lytic cycleSome viruses can enter a cell and remain dormant for long periods of time with no effects- Remain latent until stress or certain foodsOthers are immediately or intermittently harmfulHemorrhagicFever When a person bleeds to death out of all of their orifices - Caused by EbolaAntigenic Drif Genetic makeup changes over the years3 Steps to Fighting the Flu:1. Get the vaccine2. Take everyday actions3. Take antiflu viral drugs if your doctor gives you a prescriptionLeading Causes of Viral Diseases:- Influenza- Herpetic Viruses (herpes)o Human Herpes Virus 8 Kaposi’s SarcomaPlant viruses- Have RNA Genomes and enter through wounds- 3 Ways They Spread:o Contaminated Farming Toolso Insectso WindSome latent viruses steal a bit of host cell membrane as a protective envelope- Called Envelope Viruses- Ex. AIDS and the mumpsEmerging virusesNew or newly studied viruses- The Major Concerns are:o RNA mutates faster than DNAo Changing Host Specieso Globalization (importing viruses)- H5N1 – 2004o Bird Fluo No evidence of efficient human to human transmission or of airborne transmissiono There was always physical contact with a contaminated birdo 60% Mortality Rate- Coronavirus – 2003o SARS Severe Acute Respiratory SyndromeRetrovirus DNA is made on an RNA template - AIDS (caused by HIV)Download 102 Basic Types of Reproduction:- SexualFertilization of sperm and egg produces offspring- Asexual Offspring are produced by a single parent without the participation of sperm and eggo The offspring are genetic copies of the parentCells only arise from preexisting cells- Prokaryotic cells reproduce asexually by cell divisiono Binary Fission The process of asexual reproduction that involves the splitting of the parent into two approximately equal parts The single chromosome replicates, moves apart, grows membrane, and then divides Most prokaryotes and protists (no nucleus)The Eukaryotic Cell and MitosisBefore the cell starts dividing, the chromosomes replicate and produce sister chromatids- Chromatids are joined at the centromere (waist)- Each chromatid is a pair of daughter cells, containing a complete and identical setof chromosomesMitotic Phase1. Mitosis The division of the geneticmaterial2. Cytokinesis The movement of thecytoplasm to the two new cellsInterphase:- Growth 1, Synthesis, Growth 2Mitosis:1. Prophasea. Formation of early mitoticspindle An array ofG1SynthesisG2microtubules and associated proteins that form between the opposite poles of the cell during mitosisb. Centrosome The regulator of prophase; produces and organizes the spindles2. Prometaphasea. Centrosomes are at the poles of the cellsb. Nuclear envelope is breaking down3. Metaphasea. The spindle is completely formedb. Chromosomes are on the metaphase plate (the middle of the cell)4. Anaphasea. The sister chromatids are dividingb. Each copy will go to each pole5. Telophasea. Nucleus starts to form6. Cytokinesisa. Cytoplasm starts to go to each cellCytokinesis- In animals, it occurs by constriction of the cello It will completely break apart into two separate cellso Complete cleavage of the cell- In plants, a cell plate forms and then a cell wallo They are still touchingo Incomplete cleavageMitosis has 3 functions:1. Growtha. Multicellular2. Replacement of damaged or lost cellsa. Multicellular 3. Asexual reproductiona. Prokaryotes and protistsMost animals cells only divide when stimulated and some not at all- Most normal cells divide only when they are attached to the surfaceo Anchorage Dependence The cells must be attached to the surface before they divideo Density Dependent Inhibition When it gets so dense that all the cells are touching, they stop dividingGrowth Factors Proteins secreted by cells that stimulate other cells to divide- They would