Ch. 1 & 2 Intro to Micro & Cell biology of Prokaryotes

First antibiotic penicillin discovered by?

Alexander Fleming

Bacteria with flagella at BOTH poles?

Amphitrichous bacteria Amphi-both

Who is the father of microbiology and why?

Anton van Leeuwenhoek, FIRST to observe single celled organisms under (better) microscope he made

Not all bacteria have flagella. What are bacteria without flagella called?

Atrichous

Why are mycoplasmas resistant to antibiotics that interfere with cell wall synthesis?

Because they have no cell wall and there are sterols in plasma membrane. (sterol is a lipid and sustains the plasma mem.'s structure. ex- lipid).

Describe binary fission

Binary fission is the way that prokaryotes reproduce. It is the cell division into two daughter cells. It is a series of 4 steps. Step 1: the cell elongates and DNA is replicated. Step 2: the plasma membrane begins to constrict and forms a new cell wall. Step: 3 Cross walls form that separate the two DNA copies. Step 4: the cells now separate into two new daughter cells. It is very quick and efficient. Page # 166; Paragraph #2. The online eText has a great video as well.

In what way is budding different from binary fission?

Binary fission- the way bacteria normally reproduce; separation of the body into two new bodies. Budding- another way bacteria reproduce; they form a small initial outgrowth (a bud) that enlarges until its size approaches that of the parent cell and then it separates.

Why is the prevention of biofilms important in the healthcare environment?

Biofilms are an important factor in human health. For example, microbes in biofilms are probably 1000 times more resistant to microbicides. Experts at the CDC estimate that 70% of human bacterial infections involve biofilms. Most healthcare-associated infections are probably related to biofilms on medical catheters. In fact, biofilms form on almost all indwelling medical devices, including mechanical heart valves. Biofilms, which also can be formed by fungi such as Candida, are encountered in many disease conditions, such as infections related to the use of contact lenses and infections by pseudomonad bacteria. Page 157-158, Paragraphs 3-6

Which media is perferred for growing micrbobes becuae it yields the most robust?

COMPLEX MEDIA

Can replicate in many divisions creating multiple multiple morphologies ?

Cocci Ex)Staphylococci and Streptococci

Who is Carl Woese?

Created the 3 domain classifications: 1. Bacteria 2. Archaea 3. Eukarya

Metachromatic granules is an inclusion that is used to create?

ENERGY

The first vaccination "Smallpox vaccination" was discovered by whom?

Edward Jenner

Explain how transport processes differ between eukaryotes and prokaryotes

Eukaryotes use Pinocutosis (plasma membrane folds inward, engulfing particles and other extracellular liq.) and phagocytosis (engulf particles into the cell; WBC) Prokaryotes- group translocation; substance is chemically altered during transport (like adding a phosphate to a sugar) and it can no longer leave the cell (impermeable to the cell membrane)

Structure straighter and thinner than flagella that have a cold in ADHERENCE?

Fimbriae

How are endoflagella different from flagella

Flagella are external cell structures that allow for movement. Endoflagella (axial filaments) is the special flagella of "Spirochetes" that spiral tightly around the cell instead of protruding into the environment.

A sticky, gelatinous substance around the cell wall; allows cells to stick together or to the host cell?

Glycocalyx

When nutrients are low, cells break down (.....) into its proteins and carbohydrate constituents and use them for energy and resources.

Glycocalyx

How is dental plaque related here (biofilms)?

If not removed regularly, the biofilm can lead to dental caries, gingivitis, and periodontitis.

How does simple diffusion differ from facilitated diffusion? (both passive)

In simple diffusion, the substance passes between the phospholipids. In facilitated diffusion there are a specialized membrane channels.

What is the general function of inclusions?

Inclusions are stored nutrients, secretory products, and pigment granules.

Why is osmosis important?

It helps the movement of nutrients, water, and other solutes move in and out of the cell. Hypertonic: the cell would lose water and shrink. Hypotonic: the cell will swell up and possibly burst. Isotonic: same

Why is it difficult to define psychrophile, mesophile, and thermophile?

It is difficult to define due to not being rigidly defined. There are several variations of the ranges and maximum temperatures that bacterial species grow at. For instance psychrophile, their growth temperature can be at 0 degrees Celsius but some won't grow until the temperature reaches 25 degrees Celsius, even though the optimum temperature is at 15 degrees Celsius. microorganisms classified into 3 primary groups based on their range of temperature. 1. Psychrophiles- (cold-loving). 2. Mesophiles -(moderate temperature). 3. Thermophiles-(heat-loving)

What kind of molecules are peptidoglycans?

It's the cell wall for bacteria. It consists of a repeating disaccharide (sugar) connected by polypeptides (A.A) to form a lattice that surrounds and protects the entire cell.

Who believed in spontaneous generation theory?

John Needham

Who discovered Aseptic surgery?

Joseph Litwer

Which enzyme is capable of destroying the cell wall of gram-positive bacteria?

LYSOZYME (occurs naturally in salvia, tears, and mucus)

Bacteria with a tuft (many) of flagella at one pole?

Lophotrichous bacteria

How do magnetosomes behave like magnets?

Membranous structures present in 'magnetotactic bacteria'. They contain "iron-rich magnetic particles" that are enclosed in inclusions

Bacteria with a single flagellum at one pole?

Monotrichous bacteria

What is the main feature that distinguishes prokaryotes from eukaryotes?

Nucleus

First synthetic drug discovered by?

Paul Ehrlich

What is the difference between a peripheral and integral protein?

Peripheral proteins are located in the inner or outer surface of the membrane. Integral protein penetrates the membrane completely and is called "transmembrane proteins". Function: Peripheral proteins function as enzymes that catalyze chemical reactions, support, checks for changes in membrane shape during movement. Integral proteins have a pore or a hole that allows substances to enter and exit the cell. .

There are different types of flagella. Which bacteria have flagella evenly distributed over the entire cell?

Peritrichous bacteria Peri- around

What is the function of chromatophores? pg. 86

Pigments and enzymes involved in photosynthesis are found in chromatophores. A chromatophore is a membranous structure that extends into the cytoplasm. It is an infolding in the plasma membrane where bacterio-chlorophyll is located in photoautotrophic bacteria, also known as thylakoids.

Play a role in the transfer of DNA from one bacteria to another in a process called conjugation

Pili

Similar in structure to fimbraie but are much longer and rarer on the cell surface. They play a role in cell motility, like a retracting arm.

Pili

Fimbriae are made of?

Pilin- protein that cover the cell surface in varying densities.

What is the importance of the differences between prokaryotic and eukaryotic ribosomes with regard to antibiotic therapy?

Prokaryotic ribosomes are called 70S ribosomes and eukaryotic ribosomes are called 80S ribosomes, each with different types of subunits that are responsible for different types of protein synthesis. The subunits of prokaryotic ribosomes known as 30S and 50S are targeted by antibiotics and the subunits of eukaryotic cells remain unaffected by these antibiotics due to these differences in their ribosomes.

Who first observed cells under a microscope and invented "CELL THEORY"?

Robert Hooke

Who invented the GERM THEORY OF DISEASE? (microbes might cause disease)

Robert Koch (he discovered disease causing B. anthracis in cattle) Koch's postulates

Who invented the theory of Biogenesis 1858 and what is it?

Rudolf Virchow Living cells arise only from preexisting living cells

Culture medium can either be liquid or solid. Explain liquid versus solid media; what is meant by selective vs. differential media? Pg 162

Solid media "contain agar'. Liquid media "do not' contain agar. Selective media are designed to suppress the growth of unwanted bacteria and encourage growth of desired bacteria. Differential media make is easier to distinguish colonies of the desired organism from other colonies growing on the same plate.

Have one or more twists. Their diversity comes from variations in their shape and NOT replication.

Spiral bacteria Ex) Spirillum or sphillis

Where is the DNA located in a prokaryotic cell?

The DNA in prokaryotes is contained in a central area of the cell called the nucleoid, which is not surrounded by a nuclear membrane.

Where does gram-positive and negative get its name?

The name comes from its discoverer and inventor, Han Christian Gram. Under a microscope, gram-positive bacteria appear purple-blue because their thick peptidoglycan membrane can hold the dye. The bacteria is called gram-positive due to the positive result

What is the process by which an endospore is made?

The process of endospore formation w/in a vegetative cell takes several hours and is known as sporulation or sporogenesis. A newly replicated bacterial chromosome and a small portion of the cytoplasm are isolated by an ingrowth of the plasma membrane called spore septum. Then the spore septum will become a double-layered membrane that will surround the chromosome and cytoplasm which is then called a forespore, thick layers of peptidoglycan are laid down between the two membrane layers. After a thick spore coat which is protein will form around the outside membrane. The coat is responsible for the resistance of endospores to many harsh chemicals. Lastly, the original cell is degraded and the endospore is released.

What properties make endospores resistant to processes that normally kill vegetative cells? (vegetative cell-a cell of a bacterium or unicellular alga that is actively growing rather than forming spores).

They do not undergo metabolic reactions and can remain dormant for thousands of years until the right environmental conditions are met, in the meantime the spore can survive extreme conditions including heat, toxic, chemicals, and even radiation.

What are the four phases of the bacterial growth curve, and what happens in each?

They're four phases of the bacterial growth curve show the growth of cells over time. The first phase is the Lag Phase, during this time the number of cells in number change very little or may have no cell division, it can last for 1 hour to several days. Essentially what is happening during this time is the microbe population is using its energy (Metabolic energy) to Synthesis enzymes and various molecules. The second phase is called the Log Phase (Aka exponential growth phase), during this time the cells begin to divide, this is a period of growth in numbers. During this time cellular reproduction is most active, the numbers are constantly doubling and in retrospective view to a graph, we would see a linear line growth. This stage is where cell are most active metabolically The third phase is called the Stationary Phase, during this phase, the number of cells reaches equilibrium due to carrying capacity. the carrying capacity stops the growth due to limited resources, accumulation of wastes, and limited space. On a graph,, you would see straight line across referring to the limitation to support growth. The fourth phase is called the Death Phase (AKA Logarithmic decline phase), during this time the number of cells die and rapidly decrease in numbers. This decline continues until a tiny fraction of the cells are left or until the population dies out entirely. Some species go through all four phases in only a few days, others have some surviving cells almost indefinitely. Pages 167 - under phases of growth paragraph 2,3,4,5. Continued on p.168

Bacteria have sensors that alert them to chemicals or nutrients in the environment. The rate of "runs" and "tumbles" are modified. True or False

True

Who is Carolus Linnaeus?

Two-part name: Genus: 1st name- CAPITALIZED Species: 2nd name -(NOT capitalized) (Both italic or underlined)

Why is sugar added to fruit to make jams and jellies? p. 154

Water is added in efforts to manage water activity also decreases the accessible water that is available for microorganisms that allow food to go bad. Sugar is added in order to decrease water content and decreasing the risk of microorganism to grow. - foodcrumbles.com

Under what conditions do endospores form?

When essential nutrients (carbon or nitrogen) are depleted, certain gram-positive bacteria form specialized "resting' cells. Endospores are highly durable dehydrated cells with thick walls and additional layers. They are formed internal to the bacterial cell membrane.

Who discovered the first microscope?

Zacharias Jensen

What is Lipopolysaccharides (LPS)?

a complex molecule that contains lipids and carbohydrates (lipid A portion responsible for gram-neg bacterial infection)

Define: osmotic pressure, and explain the adaptations of certain archaebacteria to high osmotic pressure conditions

a. Osmotic pressure- pressure required to prevent the movement of pure water into a solution containing some solutes; pressure needed to stop the flow of water across the selectively permeable membrane b. Obligate Halophiles/Extreme Halophiles- Organisms in Dead Sea require 30% salt c. Facultative Halophiles- don't require high solute concentration, but may grow in them is the minimum pressure which needs to be applied to a solution to prevent the inward flow of its pure solvent across a semipermeable membrane. ????

Which bacterium would theoretically be more likely to grow at refrigerator temperatures: a human intestinal pathogen or a soilborne plant pathogen? 1. Explain figure 6.2, page 153

a. Soilborne plant pathogen since the human intestinal pathogens are prone to grow in high temperatures. There are more chances for soilborne pathogens to be exposed to 0°C temperature and still grow. b. Low temps in the refrigerator will slow microbial reproduction rates. Some bacteria grow in very high temperature and kill others; vise versa ????The temperature inside a set refrigerator will greatly slow the growth of most spoilage organisms and will entirely prevent the growth of all but a few pathogenic bacteria

Why are passive transport processes important to a cell?

allowing it to move molecules across the plasma membrane by moving down a concentration gradient without using energy. (high conc-low conc)

What is the distinguishing feature of spirochete bacteria?

are gram-negative, motile, spiral bacteria, from 3-500 m long and are unique in that they have endocellular flagella (axial filaments).

Tumbles > Runs, bacteria move?

away

What is the difference between the term bacillus and Bacillus?

bacillus refers to a bacterial shape. Ex) diplobacilli Bacillus- when "capitalized" and "italicized", it refers to a specific genus. For example: Bacillus anthracis (anthrax).

What is Taxis?

bacteria move towards a positive stimulus or away from a negative stimulus.

Why don't bacilli form tetrads of clusters?

because they only divide in one plane along their short axis.

Fimbraie play an important role in the formation of?

biofilms

Lipid inclusions used for?

biosynthesis

Carboxysomes is an inclusion used by photosynthetic bacteria to harvest?

carbon from CO2.

What is Acid fast cell walls?

cell walls that contain Mycolic acid. These bacteria are gram-positive and require an acid-fast stain to identify them.

Gas vacuoles which is an inclusion that allows for?

depth control

Polysaccharide granules are inclusion that contain starch and glycogen and are used for?

energy

Sulfur granules are inclusions used by bacteria as an?

energy source

Glycocalyx allows bacteria to attach to what kinds of organs?

intestines, lungs, teeth etc..

What is meant by 'generation time' for prokaryotes? pg 165

is the time required for a cell to divide and its population to double. For most bacteria, their generation time is 1-3 hours, however, for some, it can be more than 24 hours.

Culture is?

microbes being grown in culture medium

What is culture medium?

nutrient substance used to facilitate growth of microbe

Magnetosomes contain iron-rich particles enclosed in inclusions and can cause magnetotactic bacteria too?

passively align and swim along earths magnetic fields

EPS can be found in what organisms?

prokaryotic and eukaryotic organisms

Why are bacterial capsules medically important?

protect pathogenic bacteria from phagocytosis by the cells of the host. this is bad because it makes the bacteria able to cause disease in the host

Active transport is required when?

resources in the environment are low. Cells must use energy to move substance against concentration gradient.

Bacteria are distinguish by?

shape, chemical composition, nutritional requirements (metabolism).

Due to distinct nature of the bacterial cell wall, it is a good target for antibiotics because?

the cell walls are distinct from all mammal cells

What is spontaneous generation 1745?

the theory that life appears from nonliving things (later disproved by Louis Pasteur in 19th century)

How might biofilms contribute to fomites?

they can adhere to surfaces of medical equipment such as catheters.

Runs > Tumbles, bacteria move?

toward stimulus

How does biofilms form?

when microorganism adhere to the surface to some object in a moist environment and secrete a gluey slime substance.

Why are fimbriae necessary for colonization?

...? Fimbriae are necessary for colonization because they have a tendency to adhere to each other and to surfaces. They are involved in forming biofilms and other aggregations on the surfaces of liquids, glass, and rocks. It can also help bacteria adhere to epithelial surfaces in the body and cause disease. When Fimbriae are absent (because of genetic mutation) colonization cannot happen, and no disease ensues. Page 80, 1st paragraph of that page.

Bacteria range from what in size?

0.2-2.0 µm in diameter (cocci) and 2.0 - 8.0 µm in length (bacillus, spiral)

Louis Pasteur was known for what 3 things?

1. Aseptic technique (microbes destroyed by heat) 2. Fermentation & 3. Pasteurization (found microbes called yeats that convert sugar to alcohol in the absence of air, prevent spoilage by heating beer or wine to kill bacteria.

What are the two types of Glycocalyces?

1. Capsule 2. Slime layer

What are the 3 basic parts of the flagellum?

1. Filament- long whip like portion 2. Hook- connect filament to body 3. Basal body- rings that actors flagellum to the cell

What are the 7 types of inclusions?

1. Metachromatic granules 2. Polysachcharide granules 3. Lipid inclusions 4. Sulfur granules 5. Carboxysomes 6. Gas vacoules 7. Magnetosomes

Describe the differences between obligate aerobes, facultative anaerobes, obligate anaerobes, aerotolerant anaerobes, microaerophiles? (Different types of bacteria) See p. 156 for information

1. Obligate aerobes are organisms that require oxygen to live. 2. facultative anaerobes- organisms that can use oxygen when present but are able to continue to grow by using fermentation or anaerobic respiration. 3. Obligate anaerobes- grows in the absence of oxygen, dies in presence of oxygen. 4. Aerotolerant anaerobes- are fermentative and cannot use oxygen for growth. 5. Microaerophiles- do require oxygen for growth.

Name at least four ways that microorganisms may help humans

1. Produce vitamins and chemicals 2. Produce pharmaceuticals (antibiotics) 3. Produce food products 4. Produce enzymes

Extracellular polymeric substance (EPS) is a Glycocalyx that helps cells in a biofilm attach to their target environment and to each other. What are its 2 functions?

1. Protect cell within it 2. Facilitates communication among them

How do the basal bodies of gram negative and gram positive bacteria differ?

1. flagellar structure "two rings" gram-positive bacteria, 2. flagellar structure contains "four rings" gram-negative Gram-positive: THICK cell wall: CONTAIN teichoic acids Cell wall is outermost layer- NO outer membrane Sucescuptible to antibiotics Gram-negative: THIN cell wall: NO teichoic acids Outer membrane- Lipopolysaccharides (LPS) Protected from antibiotics by outer membrane

Cell wall is composed of what 3 things?

1. petidogylcan 2. proteins 3, carbohydrates

What is a capsule?

A type of glycocalyx w/ an "organized" structure attached FIRMLY to the cell wall. Protects pathogenic bacteria from phagocytosis

What is a slime layer?

A type of glycocalyx w/ an "unorganized" structure that is attached LOOSELY to the cell wall.