3VIRUSESWhat is a virus?A non-cellular particle made up of genetic material that can invade living cells.Viruses can grow and reproduce but only with the help of a host.
4STRUCTURE OF A VIRUSCapsidDNA or RNAtailtail fibersBacteriaphage
5Virus Diversity Viruses are specific to the cells they attack. Ex. HIV only attacks white blood cells, herpes only attacks cells of the lips or genitals, bacteriaphages only attack bacteriaWays of attacking cells; injecting DNA into cell (bacteriaphages) or completely entering the cell
6LIFE CYCLE OF A VIRUS 1. Attachment Virus attaches to a specific host cell2. Entryvirus injects cell with its own DNA3. Replicationhost cell destroyednew viral DNA and proteins made.4. Assemblynew virus particles assemble5. Lysis and Releasenew virus particles released.
8ARE VIRUSES LIVING?Biologists do not consider viruses living; they do not belong to ANY kingdom.Viruses can not live independently.However, in a host, viruses can grow, reproduce, regulate gene expression and even evolve.Should they be considered living?
13Reproduction Sexual reproduction conjugation A bridge forms between 2 bacteria. DNA is transferred from one to the other bacteriaAsexual ReproductionBinary fissionNo genetic recombination
14Domain Archaea Kingdom Archeabacteria Ancient BacteriaProkaryotic (no organized nucleus)Have separate evolutionary history and biochemistry from other bacteria.Found in harsh environments
15Domain Bacteria Kingdom Eubacteria Ubiquitous (commonly occurring) and diverseOccur in every habitat and environment on earth, even acidic and radioactive ones.Most are harmless or even beneficial but some are pathogenic (disease causing)Ex. Bubonic Plague, cholera, syphillus, anthrax, and leprosy all caused by bacteria.
16Identifying Bacteria 2 Types: Gram – Bacteria with a thin wall of peptidoglycanDo not stain with Gram’s StainEx. N. gonorrhoea, salmonella, E. ColiGram +Thick wall of peptidoglycanStaphyloccus, streptococcus
18IMPORTANCE Fix nitrogen - break down nitrogen to make it usable Recycle nutrients - break down nutrients of dead organisms returning the nutrients to the environment.Food and medicines - food formed from fermentation (yogurt, cheese, butter)Disease
19Disease TransmissionWord Scramble – In groups of 2 complete the word scramble cutouts.
20Word Scramble Game Unscramble the letters to spell a word using the hint and definition on the right. Letters: e, g, m, r Word: This word is a noun. This may not be seen, but it can make you sick! (Definition: a microorganism that causes diseases.) Letters: a, g, i, m, n, o, r, s This word is a noun that ends with the suffix “-ism.” This refers to an individual form of life. (Definition: a living being, a form of life considered as an entity.) Letters: c, e, f, i, i, n, o, s, t, u This word is an adjective. This can be used to describe a germ that spreads from person to person. (Definition: that which corrupts or contaminates; spreading rapidly to others.) Letters: c, e, f, i, n, t This word is a verb. Germs do this to people and cause diseases. (Definition: affect, contaminate, taint.)
21Unscramble the letters to spell a word using the hint and definition on the right. Letters: a, i, m, n, r, s, t, tWord:This word is a verb containing the prefix “-trans.” This describes the action when a germ is moved from one person to another. (Definition: send, spread, pass on.)Letters: a, i, i, m, n, n, o, r, s, s, s, tThis word is a noun. This happens not only to germs but also to radio waves. (Definition: an act or process of spreading.)Letters: a, d, e, e, i, s, sThis word is a noun. Some of this can be prevented by eating healthily and exercising daily. (Definition: illness.)Letters: m, m, o, p, s, t, yThis word is a noun. A common cold shows this as a cough, sore throat, sneezing, headache, slight fever, runny nose, etc. (Definition: a sign or indication of something)
22Keep the words that you just unscrambled in mind as we discuss the following questions. 1. What are some infectious diseases you already know about and what are their symptoms?2. What makes these diseases contagious?3. To help stop or minimize the transmission of infectious diseases, what information do you think would be important to know and what are some precautions that one could take?
23You will be simulating the transmission of diseases from one person to another. Each person will be given a cup with a liquid in it.You will exchange liquid with 3 partners by combining then splitting the contents of the 2 cups. Be sure to record who you exchange with!
24When the class is finished we will add phenolphthalein (C20H14O4) which is an indicator of bases. Phenolphthalein stays clear in water but will turn pink in the presence of a solution above 7 ph.3 of the cups had a common base, sodium hydroxide NaOH.Let’s check your cup!Now, in groups of 3 complete the summary sheet.