Chapter 1,3

Question 1

Who is Robert Hooke and why is he important?

Answer 1

• Constructed a very simple microscope; Viewed microscopic structure of cork
  
  • Named the repeating subunits he viewed as “cells”

Question 2

What did Antoni van Leeuwenhoek do?

Answer 2

• made some of the first simple microscopes allowing him to begin the first rigorous examination and documentation of the microbial world
  
  • Viewed specimens in pond water, from tooth plaque, skin, feces, etc. 1600’s
  • Called them “animalcules” and “wee beasties” (microbes) in 1676
  • called microorganisms by end of 19th century

Question 3

what are microbes?

Answer 3

•organisms that are too small to be seen with unaided eye, need microscope

Question 4

How long have microbes existed?

Answer 4

• majority of Earths history (4.6 billion yrs, fossil record indicates microbes 3.8 billion)
  
  • For the majority of Earth’s history, microbes are evolutionary ancestors of all past and present life
  • Present virtually everywhere –Very diverse–Highly adaptable

Question 5

How are microbes classified? What dude developed a system?

Answer 5

•Carolus Linnaeus (1700s) developed a taxonomic system for naming plants and animals and grouping similar organisms together
All living things can be classified into 3 domains; microbes represented in all 3
•Archaea, Bacteria, Eukarya (microbes in all 3)

Biomial nomenclature– two names – Genus species
ex: homo sapien
ex: staphylococcus aureus (S. aureus)
• An organism’s scientific name consists of its genus name (capitalized) and its specific epithet (lower case)

Question 6

define prokaryotic vs eukaryotic

Answer 6

Prokaryotic:
•no nucleus
•no membrane bound organelles (no mitochondria, chloroplasts, Golgi body, lysosomes etc)
•much smaller than euks, less complex
•includes Eubacteria (aka bacteria) and Archaea domains
•highly adaptable, found everywhere

Eukaryotic
	•contain membrane bound nucleus
	•contain membrane bound organelles
	•much larger, more complex
	•Animals, plants, fungi, protozoa/protists

Question 7

name the 2 prokaryote types:

Answer 7

• bacteria

* Archaea

Question 8

name all 4 eukaryote types:

Answer 8

• algae
• fungi
• protozoa
• helminths (not really microbes)

Question 9

name all Non-cellular infectious agents

Answer 9

• viruses
• viroids
• prions

Question 10

Define Bacteria–what to their cell walls contain? How do they reproduce? What do they consume for energy/what is their metabolism called?

Answer 10

• Unicellular prokaryotes with a cell wall containing peptidoglycan (carb and protein complex)
• Majority reproduce by a process called binary fission (Replicating chromosome and dividing into 2; precursor to mitosis)
• Most use organic compounds for energy source
• heterotrophic—Although some photosynthesize (cyanobacteria)

Question 11

Define archaea–what is the environment the typically live in?

Answer 11

• Also unicellular prokaryotes (if have cell wall, it does NOT contain peptidoglycan)
• Ancient: The first life forms were likely Archaea; Eukaryotic cells likely arose from Archaea
• Many archaea are extremophiles (Found in harsh environments, such as salty lakes, acidic hot springs, etc.)

Question 12

define fungi–cell wall, metabolism

Answer 12

• Eukaryotic; unicellular or multicellular
• Have rigid cell walls made of chitin
• Heterotrophic: obtain their food (and energy) from other organisms (thru absorption)
•includes molds, yeasts, mushrooms
Molds-multicellular organisms that grow as long; reproduce via sexual and asexual spores
Yeasts-unicellular and typically round; reproduce by budding

Question 13

Define algae–metabolism and what do their cell walls contain?

Answer 13

• Unicellular or multicellular
• Photosynthetic: Produce energy and carbodydrates from sunlight, carbon dioxide, and water; release O2
• Help form base of most food webs
• Rigid cell walls made primarily of cellulose (polysaccharides, glycoproteins)

Question 14

define protozoa–metabolism, reproduction style, what kind of movement extensions can they have?

Answer 14

• Greek for “first animals”; Unicellular; Eukaryotic; Lack cell wall (like animals)
• Heterotrophs: Absorb or ingest organic compounds for energy
• Mostly asexual reproduction
• Most move via
Flagella: long, whiplike structures
Cilia: several, hairlike protusions
Pseudopods: extensions of a cell, false legs
• Most live in water; Some cause disease (e.g., Plasmodium causes malaria)

Question 15

Define Helminths–how do they survive?

Answer 15

• Multicellular and macroscopic; Animals
• Included in study of microbiology due to importance as disease-causing organisms
• Parasites: Derive nutrients from host organism
  
  • Three groups: Roundworms; Tapeworms; Flukes

Question 16

Define viruses–how do they “survive”? what is their size compared to prokaryotes? What 2 components are they made of?

Answer 16

• Microbes so small that they were hidden from microbiologists until the invention of the electron microscope in 1932.
• All are acellular obligatory intracellular parasites
• Absolutely require a host cell to reproduce
• they are neither prokaryotes nor eukaryotes
• MUCH smaller than the smallest prokaryote
• Made of a nucleic acid (DNA or RNA) and a capsid (protein coat)

Question 17

What 2 entities are smaller than viruses?

Answer 17

• Prions: Proteinaceous Infectious Agents
  
  • just a protein! (definitely acellular)
  • destroy brain tissue (encephalopathy)
  • BSE (bovine spongiform encephalopathy)–>mad cow disease
• Viroids: Infectious RNA fragment; Known to cause disease in plants

Question 18

What is the Golden Age of Microbio?

Answer 18

• A 50 year period (from late 1800’s to early 1900’s) where huge advances in the field were made
• 4 main questions of scientists: Does microbial life spontaneously generate? What causes fermentation? what causes disease? how can we prevent infection and disease?

Question 19

Question 1: Does Microbial Life arise from spontaneous generation? (aristotle)

Francisco Redi vs Needham

Answer 19

• Was widely accepted for almost 2000 years until Francisco Redi (1668) challenged theory
  
  • he put meat in jars, covered and not covered
  • covered jars generated maggots AND jars that were covered did not generate maggots; showed that flies must be present to create maggots, they don’t just arise on their own

Needham’s experiments (1745) (performed before Leeuwenhoek discovered microbes)
• Boiled beef broth in vials (claiming hot enough to sufficiently to kill everything), cooled, and then sealed with corks; Days later, the vials were cloudy, presumably contaminated with spoilage microbes;
• Concluded that there must be some “life force” that spontaneously caused inanimate matter to come to life

Question 20

What was Spallanzani’s experiment and his theory that arose?

Answer 20

Spallanzani’s Experiments (1799)
• Boiled broth for 1 hour, sealed (while still hot); his infusions remained clear (microbe free); When he broke the seal and exposed the broth to air, they eventually became cloudly (contaminated with microbes)
• Concluded: Needham failed to sufficiently sterilize his vials (did not heat long enough or hot enough), he let them cool in the air, allowing enough time to become contaminated OR did not seal them tight enough
• Proving that spontaneous generation does NOT occur
• Biogenesis: all life arises from pre-existing life
• Critics argued against Spallanzani’s experiments–said sealed vials did not allow enough air for organisms to survive or prolonged heating destroyed “life force”

Question 21

what is Biogenesis?

Answer 21

all life arises from pre-existing life

Question 22

What was Louis Pasteur’s contribution to Biogenesis

Answer 22

• Experiments in 1861 disproved spontaneous generation once and for all and supported biogenesis
  
  • Modified Spallanzani’s experiment by using swan necked flasks, that allowed air to enter, but no bacteria to get in
  • Debate over spontaneous generation led in part to development of Scientific method
  • Observation leads to question
  • Question generates hypothesis
  • Hypothesis is tested through experiment(s)
  • Results prove or disprove hypothesis

Question 23

Question 2: What causes fermentation?

What did Louis Pasteur experiment with?

Answer 23

• Louis Pasteur was asked to figure out why wine spoils
  
  • Spoiled wine threatened livelihood of many grape growers.
  • The debate over the cause of fermentation reactions was also linked to the debate over spontaneous generation.
  • Some scientists believed air caused fermentation; others insisted that living organisms caused fermentation.
  • Pasteur conducted a series of experiments that addressed the cause of fermentation.
  • Discovered that yeast are facultative anaerobes, growing with or without oxygen.
  • In the absence of oxygen, Yeast ferments grape juice to produce alcohol
  • Anaerobic bacteria ferment grape juice to produce acids, which spoils the wine
  • Therefore, need to kill bacteria in grape juice prior to adding the yeast

Led to development of pasteurization: the use of heat to kill pathogens and reduce the number of spoilage microorganisms in food and beverages to prolong shelf life

Question 24

How does pasteurization apply to industry?

Answer 24

Industrial Microbiology
• Industrial microbiology : when microbes are intentionally used to manufacture products
• Examples: Wine, beer, cheese, yogurt; antibiotics, hormones, vitamins

Question 25

Question 3: What causes disease? What did people used to believe about what the cause is? What theory was developed and by who?

Answer 25

* Prior to the 1800s, disease was attributed to various factors such as evil spirits, astrological signs, imbalances in body fluids, and foul vapors * In 1857, Pasteur developed germ theory * Some diseases are caused by pathogens * Pathogen: a microbe that causes disease * Pathogens can include any of the groups of microbes we discussed, including bacteria, viruses, protozoa, etc. * Germ theory applies ONLY to infectious disease * today we know that diseases are also caused by genetics, environmental toxins and allergic rxns

Question 26

What did Robert Koch investigate? What techniques did he develop?

Answer 26

* Investigated the etiology of disease: etiology is causation of disease * Initiated several microbiological laboratory techniques in his search for disease agents still used today: * Simple staining methods to view bacteria * The first photomicrograph of bacteria * Techniques to estimate the number of bacterial cells in solution * The use of steam to sterilize broth media * The use of petri dishes to grow bacteria * Techniques to transfer bacteria between media using an inoculation loop * Developed Koch’s postulates: outline the steps that must be followed in order to determine causative agent of disease (Will learn these later) * Discovered causative agents of anthrax and tuberculosis

Question 27

What did Christian Gram develop? What does this help us distinguish?

Answer 27

* Christian Gram (1853–1938), a Danish scientist, developed a staining technique involving application of a series of dyes that leave some microbes purple and others pink * Gram stain is still the most widely used staining technique * distinguishes Gram-positive from gram-negative bacteria * reflects differences in composition of the bacterial cell wall

Question 28

Question 4: how can we prevent disease and infection?

Answer 28

• In the mid-19th century, modern principles of hygiene, such as those involving sewage and water treatment, personal cleanliness, and pest control, were not widely practiced. • Medical facilities and personnel lacked adequate cleanliness, and nosocomial infections were rampant Nosocomial infections or HAI: infections acquired in a health care facility

Question 29

What infection prevention methods were created by Ignaz Semmelweis, Joseph Lister, Florence Nightingale and John Snow?

Answer 29

Joseph Lister--Aseptic technique, used carbonic acid to clean surgical wounds/tools/incisions Florence Nightingale--furthered aseptic tech in soldier wound wards ordered 200 scrubbing brushes, which were used to clean the wards, developed first nursing schools John Snow--epidemiology, studied spread of cholera in contaminated water, highlighted need for clean sewage and water

Question 30

What did Edward Jenner discover?

Answer 30

* immunology * In 1796, tested the hypothesis that cow pox, a mild disease, can provide protection against small pox, a deadly disease * Noticed milkmaids never got smallpox, immune b/c of exposure to cowpox * Infected a boy with smallpox, game him a shot containing cowpox, and waited to see if he developed immunity….he did! * Named the procedure vaccination after Vaccinia virus, the virus that causes cow pox * Founded the field of immunology: the study of the body’s defenses against pathogens

Question 31

What field did Paul Ehrlich found?

Answer 31

* Founded the field of chemotherapy: the use of chemicals to destroy pathogens * Began to test various chemicals in search of a “magic bullet” that could kill pathogenic microbes but remain nontoxic to humans * Discovered chemicals effective against the agents that cause sleeping sickness and syphilis

Question 32

Name 10 things that microbes do for us/the environment.

Answer 32

1. Decomposition (bacteria) 2. Nitrogen Fixation (role in nitrogen cycle, make nutrients for plants) 3. Carbon Fixation (photosynthesis by microbes) 4. Food production (fermentation) 5. Produce antibiotics (penicillin from mold) 6. model organisms for basic sci (simple metabolism) 7. protect us from disease (normal body flora=healthy, lactic acid prevent yeast infect.) 8. Synthesize chemicals that our body can't (e.coli produces B vitamin) 9. clean environment (sewage decomposed--Bioremediation) 10. Biotechnology (gene therapy, GMOs)

Question 33

What are the 4 processes of life?

Answer 33

1. Growth: all life increases in size 2. Reproduction: DNA is genetic material, DNA synthesis follows same steps, can be sexually/asexually 3. Responsiveness: responding to environment, maintain homeostasis 4. metabolism: fundamental metabolic processes are the same (ex: photosynth and cellular resp)

Question 34

What are the 8 components of Cell Theory?

Answer 34

1. all organisms consist of one or more cells 2. cell is the basic unit of structure for all organisms 3. all cells arise only from pre-existing cells 4. all cells are very small 5. all cells contain a plasma memo 6. all cells contain peptidoglycan 7. cells contain cytoplasm 8. cells contain ribosomes to produce proteins, contain DNA

Question 35

How do prokaryotes reproduce vs eukaryotes? How many ribosomes does each have?

Answer 35

Proks: •binary fission as reproduction •contain 80 ribosomes Euks: •mitosis as reproduction •contain 70 ribosomes

Question 36

What are the shapes of prokaryotic cell morphology? Wha is monomorphic vs pleiomorphic?

Answer 36

``` Coccus •round/oval •cells can remain attached after division •Division in 1 plane •Diplococci: form pairs •Streptococci: form chains •Division in multiple planes •Staphylococci: looks like cluster of grapes •Diplo=2 •strepto=chains •staphyl=cluster ``` Bacillus •Rod shaped •diplobacilli: pairs; Streptobacilli: chains; coccobacilli: single rod ``` Spiral •one or more twists •Vibrio: curved rods •Spirilla: helical and rigid •use polar flagella for movement •Spirochetes: helical and flexible •use axial filaments for movement ``` Unusual shapes •Star shaped Stella •Square Haloarcula More info: * Monomorphic: One shape only (most bacteria are this) * pleiomorphic: Variety of shapes

Question 37

What does the external structure of bacterial cells contain (besides peptidoglycan) and what does it do?

Answer 37

* Glycocalyx: gelatinous, sticky substance that surrounds the outside of the cell * Produced inside the cell, but secreted outside of the cell wall * Composed of polysaccharides, polypeptides, or both * Two Types of Glycocalyces * Capsule: Composed of organized repeating units of organic chemicals; Firmly attached to cell wall * Slime Layer: Loosely attached to cell surface; Water soluble Functions of a glycocalyx * The stickiness allows them to attach to surfaces, such as rocks, pipes, teeth * For example, slime layers allow oral bacteria to colonize teeth, where they produce acid and cause tooth decay * Protect bacteria from destruction by host’s immune system * Capsules contain chemicals similar to those found in body; prevent phagocytosis by white blood cells * For example pathogenic strains for Streptococcus pneumoniae contain a capsule, whereas nonpathogenic strains do not * Protect cell from desiccation (drying out) * Provide a source of nutrients when energy sources are low

Question 38

What is a biofilm?

Answer 38

Biofilm: a slimy community of microbes held together by glycocalyses and fimbriae * It is estimated that at least 99% of all bacteria in nature exist in biofilms * For example: dental plaque * The slime layer of Streptococcus mutans allows it to adhere to and grow on teeth * Other bacteria adhere to S. mutans thru fimbriae * Acid production by the bacteria of this biofilm damages causes tooth decay

Question 39

what are flagella? what is the function? What protein does a flagella contain?

Answer 39

•Composed of filament, hook, and basal body--used for motility/ability to move

Question 40

What is a peritrichous vs polar flagella arrangement?

Answer 40

* Peritrichous: Cover the surface of the cell | * Polar: Found only at the ends’ Single (mono) or in tufts

Question 41

What 3 kinds of taxis can bacteria perform in response to stimuli?

Answer 41

* Chemotaxis: in response to chemical * Aerotaxis: in response to oxygen * Phototaxis: in response to light

Question 42

What are flagella runs vs tumbles?

Answer 42

* Runs: movement in a single direction; counterclockwise rotation * Tumbles: random changes in direction; clockwise rotation

Question 43

What kind of bacteria have axial filaments?

Answer 43

* Spirochetes, a groups of spiral-shaped bacteria, have axial filaments * Flagella at both ends of the cell that tightly wrap around the entire cell * Rotation of the axial filaments cause the bacteria to “corkscrew” thru a medium * Often called endoflagella because it is located between the cell wall and the outer membrane of the bacteria

Question 44

What are fimbriae and pili?

Answer 44

* Fimbriae: short, sticky, proteinaceous (shorter than flagella, have few to 100s) * used by bacteria to adhere to each other, hosts, substances in enviro * may provide some motility •Pili (singular Pilus): Special type of fimbria, type of fimbria, longer than other fimbriae but shorter than flagella * known also as conjugation pili or sex pili * have only 1 or 2 per cell, mediate transfer of DNA during conjugation

Question 45

What does peptidoglycan do for the bacterial cell wall?

Answer 45

* A complex polysaccharide composed of smaller subunits * N-acetylglucosamine(NAG) * N-acetylmuramic acid (NAM) * NAG alternates with NAM to form a glycan chain * NAG-NAM-NAG-NAM-NAG-NAM……..repeated millions of times * Tetrapeptide chains * Glycan chains (NAM-NAG chains) are attached together by crossbridges, made of tetrapeptides * Tetrapeptides: chain of 4 amino acids

Question 46

What are Gram-pos bacteria cell walls vs Gram-neg?

Answer 46

* Gram-Positive Bacteria Cell walls * Relatively thick layer of peptidoglycan * Up to 30 rows of peptidoglycan chains; 40-80% of cell’s dry weight * Contain unique teichoic acids (alcohol and a phosphate) * Gives the bacteria a negative charge; which helps move positive ions thru the cell wall * The crossbridges (tetrapeptides) joined through interbridges * Gram-Neg Bacteria Cells Walls * Contains an outer membrane (outside the peptidoglycan) made lipopolysaccharides (LPS layer) * Acts as an additional selectively permeable membrane * Contains only a thin layer of peptidoglycan (1-3 rows) * Found in the periplasm (gel-like substance) between the outer membrane (LPS layer) and inner cytoplasmic membrane * Does NOT contain techoic acids •Does NOT contain interbridges

Question 47

What is the LPS layer? What endotoxin does it produce?

Answer 47

* Lipopolysaccharide is a union of a lipid with sugar * The lipid portion is known as lipid A * an endotoxin released by dead gram-negative bacteria (when the outer membrane disintegrates) triggering fever and shock * Thus treating gram-negative infections with antibiotics can make conditions worse * Antigenic…triggering the formation of antibodies * The LPS layer is impermeable to many molecules (Including many antibiotic, such as penicillin, detergents, and enzymes) * Contains Porins

Question 48

How do some bacteria compensate for a lack of a cell wall?

Answer 48

They have a stronger plasma membrane.

Question 49

What is the fluid mosaic model?

Answer 49

The plasma membrane/cytoplasmic membrane that consists of a phospholipid bilayer embedded with various proteins

Question 50

How is a cytoplasmic membrane different in prokaryotes than euks?

Answer 50

Bacteria walls: 1. lack sterols (like cholesterol), less rigid 2. involved in energy transformations 3. capable of group translocation 4. highly infolded

Question 51

what is the function of the cell membrane?

Answer 51

* Separates the contents of the cell from the outside environment * Selectively permeable: Proteins allow or facilitate the movement of substance across the membrane * Maintains chemical and electrical gradients * Contains enzymes for energy harvesting (cellular respiration), and enzymes and pigments for photosynthesis

Question 52

Which has a more infolded membrane, euks or proks?

Answer 52

prokaryotes * increases surface area * Facilitates transport and energy transformations eukaryotes have outfoldings, or microvilli

Question 53

what are the 2 passive processes of diffusion? (no energy spent)

Answer 53

1. Simple diffusion: movement of chemicals down their concentration gradient, from an area of higher concentration to an area of lower concentration 2. facilitated diffusion: proteins act as channels or carriers to allow certain molecules to move across the membrane, along its electrochemical gradient 3. Osmosis: diffusion of water across a semi-permeable membrane Isotonic: solute concentration is the same inside/outside; water flows in and out equally Hypotonic: solute concentration is comparatively lower; if a cell is in a hypotonic solution, water flows into the cell Hypertonic: solute concentration is comparatively higher; if a cell is in a hypertonic solution, water flows out of the cell

Question 54

What are the two active processes? (requires energy)

Answer 54

•Active Transport: Moves molecules via transport proteins, require cells to expend energy in the form of ATP to move chemicals across the plasma membrane against their concentration gradient * Group Translocation: * causes chemical changes to the substance being transported * the membrane is impermeable to the altered substance, which is then trapped inside the cell (example: glucose is brought into the cell and then phosphorylated) * now that it has changed form it is "trapped" in the cell and unable to leave

Question 55

what happens when molecules are too big to move across the membrane?

Answer 55

* Rigid cell walls of bacteria prevent endo/exo-cytosis * Extracellular enzymes: bacteria can secrete enzymes onto the surface of large molecules and break them into simpler ones * Proteins into amino acids; Polysaccharides into simple sugars * These small molecules can then be transported into the bacteria

Question 56

what is the cytoplasm for prokaryotes? what are inclusions?

Answer 56

cytoplasm (cytosol) : Primarily water (about 80%), & some dissolved substances, such as ions, carbs, enzymes, wastes * In Bacteria * Contains: Nucleoid area, DNA is concentrated * Lacks: membrane bound organelles, includes nucleus * Inclusions: reserve spots of lipids, starch, other chemicals, store stuff until used

Question 57

What is the nucleoid area? what is the important thing about bacterial DNA?

Answer 57

Densely packed region of DNA in bacterial cells, but not contained by a membrane * Bacterial chromosomal DNA contains essentially no repetitive “junk DNA” * Virtually all of the DNA is functional

Question 58

what are bacterial endospores? How does this affect our health?

Answer 58

* unique structures produced by some bacteria that are a defensive strategy against unfavorable conditions * Found primarily in the 2 genera: Bacillus and Clostridium * Essentially it is a dormant version of a cell—does not reproduce * The endspore is composed of a highly keratinized spore coat surrounding the bacteria’s membrane, DNA, and peptidoglycan of DNA, 2 membranes, a thick layer of peptidoglycan * Making it highly resistant to heat, dessication, chemicals, and radiation * When environmental conditions become favorable, endospores germinate back into vegetative cells (normal, metabolizing cells) * serious concern to food processors, health care professionals, and governments because they are resistant to most treatments

Question 59

What are bacterial ribosomes and what is the function? how does the different size of Euk ribosomes and Prok ribosomes help us target antimicrobial drugs?

Answer 59

* Ribosomes are nonmembranous organelles * Function: site of protein synthesis in cells, composed of protein and ribosomal RNA (rRNA) * Bacterial cells have thousands of ribosomes in their cytoplasm * their size is expressed in Svedbergs (S) * determined by their sedimentation rate (rate at which they move to the bottom of a test tube during centrifugation) * prokaryotic ribosomes are 70S, and are smaller * eukaryotic ribosomes are 80S and are larger * The fact that they are different allows bacterial ribosomes to be a target for antimicrobial drugs

Question 60

What is the function of bacterial cytoskeletons? (made of protein fibers)

Answer 60

•Functions: 1. helps bacterias shape 2. participates in cell division 3. a contractile cytoskeleton helps bacterium Spiroplasma to swim through enviro

Question 61

What is the archaea external structure, Glycocalyce? What is the function?

Answer 61

* Glycocalyces: function in adherence and biofilm formation * Made of polysaccharides and polypeptides (like bacteria) * unlike bacteria, the presence of a glycocalyx does not appear to result in pathogenicity

Question 62

How are flagella in Archaea diff than bacteria?

Answer 62

* function in a manner similar to those of bacteria But MUCH slower * However, they are structurally distinct * Smaller * Composed of different proteins than bacteria (frequently have sugar molecules attached to the proteins) * Powered by stored ATP molecules (in bacteria, it is the flow of H+ ions)

Question 63

What are fimbriae and Hami in archaea?

Answer 63

•Fimbriae: structurally and functionally similar to those of bacteria * Hami: unique proteinaceous fimbriae-like structures * a helical filament with prickles and a terminus that divides into three curved hooks * acts in the same fashion as the fimbriae, attaching an archaea to surfaces * A single archaeon can contain over 100

Question 64

What is the difference between gram-neg/gram-pos cell walls in Archaea?

Answer 64

* Gram negative archaeal cells have an outer layer of protein rather than a LPS layer, but still stain pink * Gram positive archaeal cells have a thick cell wall, and stain purple

Question 65

What don't archaea have that bacteria do?

Answer 65

Peptidoglycan cell wall archaea have specialized polysaccharides and proteins instead

Question 66

what are Archaea cell membranes made of?

Answer 66

lipids with hydrocarbons, attached by ether linkages cell membranes are mechanically stronger at higher temps than bacteria.

Question 67

what ribosome count do Archaea have?

Answer 67

70S

Question 68

What do the glycocalyces provide for the eukaryotic cells?

Answer 68

* Not as organized as prokaryotic capsules * Help anchor animal cells to each other * Strengthen cell surface * Provide protection against dehydration * Function in cell-to-cell recognition and communication * Found in animal cells and some protozoa

Question 69

What composes plant cell walls?

Answer 69

cellulose

Question 70

what composes fungal cell walls?

Answer 70

chitin or polysaccharides

Question 71

what composes algae cell walls?

Answer 71

cellulose, agar, carrageenan, algin

Question 72

how are euk cytoplasmic membranes similar to bacteria? what is different?

Answer 72

same: fluid mosaic of a bilayer of phospholipids and a variety of proteins diff: •Contain steroid lipids (such as cholesterol in animal cells) •to help maintain fluidity

Question 73

what are the types of endo/ecxocytosis in Euks?

Answer 73

* Phagocytosis: Pseudopods extend and engulf particles. | * Pinocytosis: Membrane folds inward bringing in fluid and dissolved substances.

Question 74

are euks capable of group translocation?

Answer 74

NO

Question 75

Describe euk flagella.

Answer 75

* anchored within the cytoplasmic membrane * the shaft of a eukaryotic flagellum is composed of a protein called tubulin * vs. flagellin in bacteria * eukaryotic flagella undulate (in waves) vs. rotating in bacteria * function to rhythmically to push or pull the cell through the medium

Question 76

describe cilia in euks.

Answer 76

* same structure as flagella but are much shorter; more numerous than flagella (hundreds on 1 cell) * In single-celled eukaryotes, rhythmic beating propels single-celled eukaryotes through their environment * In more complex organisms, use cilia to sweep substances in the local environment, * example: the ciliary escalator is composed of mucus covered cells in the upper respiratory tract that sweep bacteria & dust out of the respiratory system

Question 77

What does the cytoplasm of euks contain that proks don't?

Answer 77

membrane bound organelles

Question 78

what are some NONmembranous organelles of euks? What are some membranous organelles?

Answer 78

NON •Ribosomes (protein synthesis), Cytoskeleton, and Centrioles/Centrosomes MEMB •Nucleus, Endoplasmic Reticulum (rough and smooth), Golgi Complex (body), Mitochondria, Chloroplasts, Lysosomes

Question 79

what ribosome S is the cytoplasm of eukaryotes composed of?

Answer 79

* Larger than prokaryotic ribosomes (80S versus 70S) * Composed of 60S and 40S subunits vs 50s and 30s * Found freely in the cytoplasm or attached to the rough ER * However, chloroplasts and mitochondria contain 70s ribosomes

Question 80

What does the euk cytoskeleton provide?

Answer 80

* Much more complex in eukaryotes * Anchors organelles * Assists in cytoplasmic streaming * Produces basic shape of the cell * Plays important role in mitosis/meiosis * Made up of tubulin microtubules, actin microfilaments, and intermediate filaments

Question 81

What does the nucleus of euks contain?

Answer 81

* contains most of the cell’s genetic material in the form of DNA inside the nucleus: * nucleoplasm (semi-liquid matrix) * also contains chromatin * a threadlike mass of DNA and associated histone proteins * chromatin becomes visible as chromosomes during mitosis * surrounding the nucleus is a double membrane called the nuclear envelope * contains nuclear pores that function to control the import and export of substances through the envelope. * Most of eukaryotic DNA is junk

Question 82

What is the mitochondria and chloroplast theory?

Answer 82

Theory: how mitochondria and chloroplasts arose (mito from aerobic prokaryotes; chloro from cyanobacteria) * Explains the evolution of mitochondria and chloroplasts (proposed by Biologist Lynn Margulis in 1967) * Eukaryotes formed from union of small aerobic prokaryotes with larger anaerobic prokaryotes * The Smaller prokaryotes were ingested by the larger prokaryotes and became internal parasites (rather than digested as a food item) * Lost ability to exist independently from host cell * Evolved into mitochondria * Retained its own membrane (internal) as well as the membrane of the host (when it was engulfed); retained its own internal structures (ribosomes and DNA) * Larger cell became dependent on parasites for aerobic ATP production * Similar story with Chloroplasts (original bacteria thought to be a cyanobacteria)

Question 83

What are mitochondria and chloroplasts?

Answer 83

Mitochondria •produce most of cells ATP Chloroplasts •Light harvesting structures found in photosynthetic euks (algae and plants) •BOTH have properties similar to bacteria 1. both size of bacteria cell relatively 2. surrounded by 2 membranes (highly unfolded inner membranes, inner membrane involved in energy transformation) 3. possess own DNA (circular DNA—prokaryotic fashion) 4. possess ribosomes (70S bacteria, 80S eukaryotic) 5. reproduce separate from rest of cell