Chapter 3 – Microbiology Answers – Flashcards
Unlock all answers in this set
Unlock answersquestion
| prokaryote vs eukaryote |
answer
| prokaryote- no membrane bound organelles like nucleus eukaryote- plants, animals, contains membrane bound organelles |
question
| glyocalyces 2 types functions |
answer
| composed of polysaccharides, polypeptides, or both. capsule or slime layer -provides protection rom drying out and can play a role in the ability of pathogens to survive and cause disease - allows FOR ATTACHMENT TO SURFACES -ex; unencapsulated strains of bacteria that cause pneumonia don't cause it because defensive cells can destroy it |
question
| capsule |
answer
| when the glycocalyx of bacterium is composed of organized repeating units of organic chemicals firmly attached to the cell's surface. |
question
| slime layer |
answer
| when the glycocalyx is loose and water soluble |
question
| flagella |
answer
| -most notable means of movement -long hollow filament, a hook, and a basal body. - composed of flagellin protein - lengthens by growing at its tip -ract to external wetness and inhibit growth in dry habitats. -TAXIS=MOVEMENT IN RESPONSE TO STIMULUS (light or chemicals) receptors for light or chemicals on the surface of the cell send signals to the flagella, which then adjust their speed and direction of rotation. A. petitrichous flagella- cover the surface of the cell B. single polar flagella- only at end C.tuft of polar flagella- a few at ends only |
question
| taxis |
answer
| movement in response to stimulus (flagella) |
question
| what kind of flagella cover the surface of the cell |
answer
| peritrichous flagella |
question
| what is the most notable means of movement |
answer
| flagella |
question
| fimbriae |
answer
| rod like extensions made of protein, sticky, bristle like and they adhere to one another and to substances in the environment (MORE NUMEROUS AND SHORTER THAN FLAGELLA) -ATTACHMENT TO OTHER BACTERIA AND SURFACES - IMPORTANT IN BIOFILMS (attach using fimbriae and lycocalyces) - SOME ACT AS ELECTRICAL WIRES -PILUS- fimbriae used to transfer dan from one cell to another |
question
| what external structure allows for attachment to other bacteria AND surfaces |
answer
| fimbriae |
question
| what are the rod like extensions made of protein, sticky, bristle like |
answer
| fimbriae |
question
| pilus |
answer
| a special type of fimbriae that is used to transfer DNA from one bacterial cell to another by a process called CONJUGATION |
question
| function of cell wall |
answer
| -provide structure and shape to cell - protects from osmotic forces - assists some cells in attaching to other cells or in resisting antimicrobial drugs. - gives bacteria cells their shaoes |
question
| spherical= rod like= what do they exist in (form?) |
answer
| spherical= COCCI(single,chains, clusters, or cuboidal packets) rod like= BACILLI (single or chain) |
question
| staphylococci |
answer
| clusters |
question
| streptococci |
answer
| chains |
question
| sarcinae |
answer
| cuboidal packets |
question
| do bacteria have cell walls? |
answer
| yes, except mycoplasma which does not |
question
| mycoplasma |
answer
| a bacteria that doesn't have a cell wall |
question
| cell walls are composed of ___________ |
answer
| peptidoglycan - a complex polysaccharide made of repeating subunits of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) which are like glucose - chains are attached to other chains by cross links of four amino acids (tetra peptides) |
question
| what do you call 4 amino acids joined by peptide bonds, and where would you find one |
answer
| a tetrapeptide the cell wall |
question
| what are the two types of bacterial cell walls |
answer
| gram negative and gram positive |
question
| gram positive |
answer
| thick layer of peptidoglycan that also contains unique chemicals called teichoic acids (gives surface negative charge) some of which are covalently linked to lipids forming lipoteichoic acids (anchor the peptidoglycan) -APPEARS PURPLE -no porins 1. cross linking heavy 2. thick layer of peptidoglycan 3. teeichoic acid (give surface -) 4. lipoteichoic acid (anchor the peptidoglycan) |
question
| which has porins? gram negative or gram positive |
answer
| gram negative because it has the outer membrane which can have porins |
question
| which has a thick layer of peptidoglycan, gram - or + |
answer
| + |
question
| gram positive appears |
answer
| purple |
question
| gram negative appears |
answer
| pink |
question
| gram negative |
answer
| thin layer of peptidoglycan, but outside this layer there is also another outer bilayer membrane(external to the cell wall) composed of two different layers. inner layer: phospholipids and proteins outer layer: lippopolysaccharide/LPS (endotoxin). when these cells die they release a lipid which causes symptoms. 1.cross linking lightly 2. thin layer of peptidoglycan 3. lipoproteins, phospholipids, in extra outer bilayer membrane (inner layer of it) 4.LPS layer- created by union of a lipid and sugar (contains lipid A also known as endotoxin (in the lipid portion) which causes symptoms such as fever, vasodilation, inflammation, shock, and blood clotting in humans ) 5. drugs are a danger due to this lipid A being a threat when the cells die 6. drugs may be ineffective due to outer layer stopping the entrance of drugs like penicillin into the underlying peptidoglycan 6. contains a periplasmic space which contains the petidoglycan and periplasm |
question
| what is the structure of a gram negative cell |
answer
| -it has a thin cell wall/ layer of peptidoglycan - it has an extra layer outside the cell wall (this layer is composed of two layers)(inner layer is phospholipids and proteins, outer layer is lipopolysaccharide.LPS or endotoxin) |
question
| what is the outer layer of gram negatives extra outer membrane? |
answer
| it is the LPS layer, or endotoxin layer (lipopolysaccharide) that contains lipid A which causes fever, vasodilation, inflammation, shock, and bloodletting |
question
| why is gram negative bad |
answer
| because when you kill large amounts of gram negative bacteria a lot of lipid a is being released from the outermsmbrane LPS/endotoxin layer. - the gram negative outer membrane can also stop chemicals from passing through like penicillin. |
question
| what is in the inner membrane layer of the extra membrane of gram negative cells |
answer
| phospholipids and proteins |
question
| what extra chemical does gram positive bacteria have? |
answer
| teichoic acids |
question
| techie acids covalently link to lipids and form |
answer
| lipoteichoic acids |
question
| what do lipoteichoic acids do |
answer
| anchor peptidoglycan |
question
| the periplasmic space contains is this in gram neg or pos |
answer
| gram neg it contains peptidoglycan and periplasm |
question
| mycobacterium |
answer
| -species that have 60% my colic acid in their ell walls -mycolic acid: a waxy lipid, helps cells survive drying out - the my colic acid makes staining difficult - ACID FAST STAIN USED -CALLED ACID FAST BACTERIA |
question
| acid fast bacteria are from the __________ species they have ______ which makes them hard to stain |
answer
| mycobacterium waxy lipid |
question
| cytoplasmic membrane |
answer
| - cell membrane, plasma membrane - phospholipid bilayer -fluid mosaic model -selectively permeable -proteins allow things to pass by acting as transport or channels -interior of cell is more electrically negative that outside |
question
| __________charged substances tend to be attracted into cells |
answer
| positively (because the cell is negative so it attracts positive) |
question
| solute solvent |
answer
| solute- salt solvent-water |
question
| osmosis |
answer
| diffusion of water across a semipermeable membrane until equilibrium is reached or until the pressure of water is equal to the force of osmosis |
question
| isotonic hypertonic hyptonic |
answer
| isotonic- when 2 solutions on either side of the PM have the same concentration of *solutes* the two solutions are said to be isotonic. hypertonic- when the concentration of solutions(the amount of solutes within the solvent) are unequal the solution with the higher concentration of solutes is said to be hypertonic to the other hypotonic- when the concentration of solutions are unequal, the solution with the lower concentration of solutes is said to be hypotonic to the other |
question
| when thinking about isotonic, hypertonic, hypotonic, think about which has higher or lower concentration of __________ in biology these terms are used relative to the _________ of the cell |
answer
| solutes (salt) interior of the cell *** |
question
| most cells are ________ to their environment |
answer
| hypertonic |
question
| cell placed in hypertonic solution (hypertonic to inside of cell so it has more solutes in the solution) it will__________ |
answer
| shrivel, lose water |
question
| if a cell is placed in a hypotonic solution it will |
answer
| swell, gain water |
question
| what does cell wall help in regards to osmosis? |
answer
| cell wall serves as a means to resist further osmosis and prevent cells from bursting |
question
| cytoplasm is also called _______ it contains |
answer
| cytosol ions, amino acids,aqueous solution |
question
| ribosomes |
answer
| -protein synthesis -translation -in prokaryote all ribosomes exist in cytoplasm -ribosome smaller in prokaryote |
question
| how are ribosomes different in prokaryote |
answer
| they are smaller and all located in the cytoplasm |
question
| internal structures of prokaryote |
answer
| cytoplasm (required) ribosomes (required) genetic material (requires) endospores (optional) |
question
| the genetic material in a prokaryotic cell is |
answer
| a single, circular chromosome (in nucleoid region) |
question
| endospores |
answer
| - bacillus or clostridium (both human pathogens) -bacterial cells that are metabolically active are called vegetative cells, these cells produce endospores which are metabolicaly dormant |
question
| bacterial cells that are metabolically active |
answer
| vegetative cell |
question
| cells that are metabolically domarnt |
answer
| endospores |
question
| based on how the endospore is made, the end result is very resistant to ? |
answer
| dehydration, heating, freexing, UV light |
question
| endospores are very |
answer
| resistant! |
question
| sporulation |
answer
| the process of making an endospore ( which protects chromosome so it isn't destroyed) |
question
| when does sporulation take place |
answer
| when their is a lack of needs/unfavorable circumstances such as a lack of nutrients or water cause sporulation in order to survive |
question
| is the process of sporulation reversible? |
answer
| yes, endospores may be converted back to the vegetative state (this is called germination) this happens when unfavorable circumstances are removed |
question
| the reverting of an endospore back to the vegetative state is called |
answer
| germination |
question
| 4 things all cells have: |
answer
| cell membrane, cytoplasm, genetic material, ribosomes |
question
| cocci- bacilli- vibrio- spirilli- spirochete- |
answer
| cocci- diplococci, streptococci,staphylococci bacilli- diplobacilli, streptobacilil vibrio- rod shaped with slight curve, comma shape spirilli- rod shaped, twisted, very stiff, exist only as individual spirochete- rod shaped, twisted, but very flexiblelike slinky, only exists as individual |
question
| you should give _______ solution for dehydration |
answer
| isotonic |
question
| if blood cells are shriveled what is the explanation |
answer
| a hypertonic solution must have been given |
question
| if the cell was intact, which environment would that cell be able to survive? |
answer
| hypotonic |
question
| true or false, gram negative never has cross linking? |
answer
| false, gram negative may have some cross slinking just not ever as much as gram positive |
question
| how does penicillin work |
answer
| it inhibits cross link formation in newly synthesized cells - this damages boundary structures of the cells cane the cells die because our bodies are hypotonic |
question
| which have phosphoolipids in the cell membrane? gram positive or gram negative? |
answer
| both |
question
| which bacterial infections are harder to treat? positive or negative? |
answer
| negative |
question
| sketch gram positive and negative cell walls |
answer
question
| ***ARE LIPOPROTEINS IN GRAM + and -??? |
answer
question
| mycobacterium is gram _______ and ________ acid is also found in the cell wall |
answer
| gram positive mycolic acid |
question
| for bacteria the cell wall provides protection from osmosis but only if it is in a __________ environment |
answer
| hypotonic |
question
| endospore is an internal structure unique to |
answer
| prokaryotes ( but not all can produce the) |
question
| what are the two families of endospore we are interested in |
answer
| bacillus and clostridium (human pathogens) naturally found in soil, typically in the endospore state where would easily encounter them. |
question
| ________ is produced through the process of sporulation |
answer
| endospore |
question
| one __________ cell (a metabolically active state) produces one endospore |
answer
| vegetative |
question
| the process of ___________ returns one endospore back to the sensitive, vegetative state. |
answer
| germination |
question
| anthrax |
answer
| bacillus anthracis endospores put in envelopes and mailed and then inhaled |
question
| archae lack |
answer
| peptidoglycan in the cell wall |
question
| bacteria and arachaea reproduce |
answer
| asexually |
question
| peptidoglycan is a complex ___________made of repeating subunits of ________ and ________ chains are attached to other chains by _______ which are cross links of four amino acids |
answer
| is a complex polysaccharide repeating subunits of NAG, NAM tetrapeptides |
