BIOL 201 Ch 4 Learning OB

Define turgidity, osmotic lysis, plasmolysis.

turgidity: how swole cell is osmostic lysis: bursting of cell plasmolysis: shrinking of cell

Define osmosis

diffusion of water across a selectively permeable membrane

Illustrate the passage of a secretory protein to the plasma membrane

1. secretory protein synthesized on ribosome in rough ER 2. transported to golgi complex by transport vesicle 3. transport to plasma membrane by secretory vesicles from golgi complex

Define endosymbiosis and ectosymbiosis and explain the difference between the two. In each form of symbiosis, what organisms are described in "Why microbiologists study termites?"

Endosymbiosis: symbiotic relationship where one organism lives within another (Trichonympha sphaerica) Ectosysmbiosis: symbiotic relationship with organisms that live outside its body (Mixotricha)

Name the building blocks of peptidoglycan and the linkage

NAG: N-acetylglucosamine NAM: N-acetylmuramic acid glycosidic linkage

Describe the cell wall structure of a gram positive bacterium with a diagram

NAMs linked with tetrapeptides + many layers of peptidoglycan sheets + teichoic acids binding layers together + lipoteichoic acids linking peptidogylcan to cell wall

Name the three structural components found in the lipopolysaccharide

O polysaccharide + core polysaccharide + Lipid A

Name two groups of bacteria that have endoflagella

Treponema pallidum + Borrelia burgdorferi

Name the genera of bacteria that produce endospores

bacillus (Bacillus anthracis) clostridium (Clostridium botulinum)

Name the two major groups of prokaryotic organisms.

bacteria + archaea

Explain why unencapsulated strains of Streptococcus pneumoniae cannot cause pneumonia

can't resist phagocytosis without capsule (easily cleaned by immune cells)

Describe the action of lysozyme and explain whether lysozyme should have the same effect on both the gram positive bacteria and the gram negative bacteria

contain digestive enzymes that kill bacteria when they phagocytize them lysozymes don't affect gram + & - bacteria the same --> gram - has extra layer of protection

Describe the function of nuclear pores

control movement of substances between nucleus & cytoplasm

Define selective permeability of the plasma membrane and discuss its significance to a cell.

control of movement of substances in & out of the cell --> allows cell to control what comes into its internal envrionment

Define endospore and list endospore functions

essential chromosomes bacteria needs to live --> when conditions are harsh, they take essential genes and compact them into invincible spores

Describe the difference in the subunit size between an eukaryotic ribosome and a prokaryotic ribosome.

eukaryotic ribosome: 40S + 60S 80S prokaryotic ribosome: 30S + 50S 70S

Describe the following structures and their functions: flagella (Figs. 8 and 9), endoflagella or axial filaments (Fig. 4.10), fimbriae (Fig. 4.11), pili (Fig. 8.27)

flagella: appendage that allows for motilty endoflagella/axial filaments: flagella built into a cell fimbriae: hair like appendages allowing for adherence to host tissues & cells pili: allows for twitching & gliding motility + exchange of DNA between gram - bacteria

Describe the four groups of eukaryotic microorganisms, see pp. 3-6 and give two specific examples for each group

fungi: cell walls containing chitin & heterotrophic + include yeast, mold, mushrooms + some medically important ex) Candida albicans, Crytococcus neoformans algae: cell wall + photosynthetic & autotrophic + limited medical importance ex) phytoplankton, kelp protozoa: unicellular + motile + heterotroph ex) Plasmodium spp, Trichomonas vaginalis helminths: flatworms & roundworms + some medically important + microscopic @ some stages of life cycle + some parasitic ex) Trichinella spiralis, Enterobium vermicularis

Define glycocalyx, capsule, and slime layer

glycocalyx: extracellular matrix of secreted mucus capsule: type of glycocalyx that is organized & firmly attached to the cell wall slime layer: type of glycocalyx that is unorganized & loosely attached to the cell wall

Describe the commonly used classification scheme for clinically important bacteria

gram +/ gram - & cocci/rods (bacilli)

Compare the cell walls of gram-positive bacteria and gram-negative bacteria with regard to peptidoglycan, teichoic acids/lipoteichoic acids, outer membrane, and periplasmic space.

gram-positive: many layers of peptidoglycan + has teichoic acids/lipoteichoic acids + no outer membrane + no periplasmic space gram-negative: thinner cell walls of peptidoglycan + no teichoic acids/lipteichoic acids + has outer membrane + has periplasmic space

Define endocytosis

ingestion of particles or cells by eukaryotic cell

Define isotonic, hypotonic, and hypertonic solutions (see Fig. 4.18). a.Describe possible structural changes a bacterium may experience in each of the solutions

isotonic: no net movement of water --> no change hypotonic: net movement of water inside cell due to higher intracellular solute concentration --> lysis hypertonic: net movement of water outside cell due to higher extracellular solute concentration --> plasmolysis

Draw a portion of the plasma membrane as shown in Fig. 4.14 and identify the major structural components and list functions associated with these structural components

lipid bilayer: selective permeability peptidoglycan: selective permeability outer membrane: added protection peripheral proteins: enzymes + support + change membrane shape integral proteins: channels for transport

Describe the structure of the outer membrane of gram negative bacteria with a diagram

made up of phospholipids + lipopolysaccharides (O polysaccharide + Lipid A) + porin

Define nucleoid, bacterial chromosome, and plasmid

nucleoid: non membrane bound structure contains DNA for bacteria bacterial chromosome: single circular double stranded DNA plasmid: extrachromosomal DNA capable of independent replication

List the organelles shown in a generalized eukaryotic cell,

nucleus + rough/ smooth ER + mitochondria + ribosome + golgi complex + lysosome + peroxisome

Describe the function of each organelle

nucleus: contains liner DNA endoplasmic reticulum: translate proteins from RNA (rough) + make cholesterol, sterols, hormones (smooth) golgi complex: modify transport vesicle to transfer vesicle to transport proteins to other parts of the cell

Define organelle.

organ of cell

Determine the length of the flagella and the type of flagellum arrangement shown in Fig. 4.9b.

peritrichous: flagella all over cell monotrichous: 1 flagella on 1 side lophotrichous & polar: > flagella on 1 side amphitrichous & polar: flagella on both poles

Explain the structural difference between the plasma membrane and the outer membrane

plasma membrane = thinner + more flexible outer membrane = thicker + stronger + more rigid

Define bacterial inclusion. Give at least one example.

pockets of nutrients, heavy metals, & things the cell may need later

Describe the function of the glycocalyx.

prevents immune system from grabbing cell if it enters the body --> aids in colonization attachment + biofilm formation + nutrient source + resistance to phagocytosis

List differences between the prokaryotic and the eukaryotic cells based on Table 4.2, Figs. 4.6 and 22 with regard to the size, nucleus, membrane-enclosed organelles, ribosome, and chromosome structure

prokaryotic: typically 0.2-2.0 μm in diameter (smaller) + nucleoid + no membrane bound organelles + 70S ribosome + singular circular chromosome eukaryotic: typically 10-100 μm in diameter (larger) + true nucleus + membrane bound organelles + 80S ribosome + multiple linear chromosomes

Define the prokaryotic cell and the eukaryotic cell

prokarytoic cell: cells with no membrane-bound nucleus eukaryotic cell: cells with membrane-bound nucleus containing DNA

List major functions of the bacterial cell wall

protection + morphology + host-bacterium interactions + selective permeability

Define the function of ribosomes. Describe the structure of a ribosome found in a bacterium

protein synthesis --> 2 subunits (30S & 50S --> 70S)

Identify the structural components shown in Fig. 4.25 and Fig. 4.26, including TEMs.

rough ER: house ribosomes ribosomes: synthesize proteins from RNA cisterna: processing & sorting smooth ER: synthesize cholesterol + sterols + hormones

Define rough ER and smooth ER; list functions associated with each type.

rough ER: house ribosomes that synthesize proteins smooth ER: synthesize cholesterol + sterols + hormones

Define periplasmic space

the space between the outer and inner membrane of Gram neg bacteria. It contains enzymes and binding proteins that assist in nutrient uptake

Define chromatin.

threadlike mass of DNA

TEM: A portion of the cell wall of a gram negative bacterium. How would a TEM of the cell wall of a gram positive bacterium differ from this one?

would have no outer membrane + thicker peptidoglycan layer + no periplasmic space