scientists
Scientist who developed a classification system for streptococci based on antigens in their cell walls
Who is Rebbecca Lansfield
What molecules make up a lipid? give an example
nucleic acid?
protien?
lipid- C H O P N and or S, nonpolar, triglycerides, steroids
nucleic acid- C H O N P, building blocks of DNA and RNA, ATP
protein- C H O N sometimes S, COOH and NH2 functional groups
Compare and Contrast prokayotic and eukaryotic plasma memebranes:
Similar: In function and basic structure
Different: Prokaryotic: No carbohydrates, lack sterols,
Eukaryotic : Carbohydrates, sterols, act as a receptor.
How is ATP made in noncyclic photophosphorylation? What is the final electron acceptor in this process?
When is cyclic photophosphorylation used? How is energy generated in this process?
In non-cyclic photophosphorylation the photolysis of water produces electrons that generate a proton motive force which is used to produce ATP; the electrons are shuttled by NADPH to the ETC and are used to reduce NADP+ to NADPH.
The final electron acceptor in non-cyclic photophosphorylation is NADPH.
In cyclic photophosphoryation, electrons cycle through photo system I and the electron transport chain. Electrons that exit the cycle are incorporated into NADPH in non-cyclic photophosphorylation.
excited electrons from PSII fall back into photo system 1, enters the electron transport chain, makes ATP for the cell, get excited by light and fall back onto PSI, back making more ATP
Why is a hypertonic environment problematic for microbes?
In hypertonic environments, cells can become dehydrated, causing crenation or shriveling of the cell. In cells that lack a cell wall, changes in osmotic pressure can lead to crenation. Crenation happens particularly in hypertonic environments, whereas cell lysis happens in hypotonic environments.
Disproved spontaneous generation, provided proof of biogenesis and fermentation
Louis Pasteur
What microscope would you use to visualize Unstained live tissue when it is desirable to see some intracellular detail in color
DIC microscope
Compare and Contrast prokaryotic and eukaryotic cell wall and where glycocalyx is found in both
Prokayotic cell wall- made up of peptidoglycan
glycocalyx 2 types
Capsule- surrounds outer most layer, allow bacteria to attach to surfaces, evades phagocytosis contributing to virulence
slime layer loose found in biofilms
Serve as a source of nurtients.
Eukayotic
glycocalyx in the plasma membrane
Describe the chemical reactions from glycolysis to entering the krebs cycle
the oxidation of glucose to pyruvic acid produces ATP and NADH in Glycolysis.
In the Preparatory Stage of Glycolysis: 2 ATP are used and Glucose is split to form 2 glyceraldehyde-‐3-‐ phosphate
In the Energy-‐Conserving Stage of Glycolysis:2 glyceraldehyde-‐3-‐phosphate are oxidized to 2 pyruvic acid, 4 ATP are produced, 2 NADH are produced.
Explain why a hyperthermophile is unlikely to be a human pathogen. What type of
microbe is more likely to be a human pathogen?
The human bodyʹs temperature is approximately 37°C, which is not a favorable
environment for a hyperthermophile, which has an optimal growth temperature of 80°C
or higher. The hyperthermophile would either not grow at all or would grow very slowly
in the human body. A mesophile is more likely to be a a human pathogen.
Which scientists showed that genes code for enzymes
Beatle and Tatum
What type of bonds do you see in a the primary shape of a protein? what type of synthesis reaction forms this bond
Peptide bonds are formed between amino acids and are formed by dehydration synthesis
Why are mycoplasmas resistant to antibiotics that interfere with cell wall synthesis?
mycoplasma have an atypical cell wall. Most antibiotics that target cell wall synthesis target peptidoglycan not mycolic acids.
Explain the Calvin cycle
How many G3P are needed for each glucose?
What is used and what is made in the regeneration steps?
fixation- CO2 combines with RuBP making 3-PGA
reduction- 6ATP and 6NADPH are used to convert 3-PGA to 3 molecules of G3P
Regeneration- 2 molecules of G3P are used to make glucose and the other one goes back in the cycle to regenerate Rubisco
Describe the steps of binary fission.
1) Replication of the circular prokaryotic chromosome begins and the cell begins to
elongate. 2) The duplicated chromosomes separate and continue to move away from each
other toward opposite ends of the cell. The cell wall and plasma membrane begin to
constrict in the middle of the cell. 3) A cross-wall forms, separating the two copies of
DNA from one another. 4) After the septum is complete, the cell pinches in two, forming
two daughter cells.
Who was the scientist who used the first synthetic chemotherapeutic agent
Ehrlich
Explain the differences between basic and acidic dyes and how they are used.
Basic dyes are (+) charged, resulting in the stain being attracted to the (-) charged cell surface of microbes and easily entering cells; (methylene blue, crystal violet, safranin, and malachite green) we use these more frequently. Acidic dyes like nigrosin negatively charged, so
they do not easily enter cells. They stain the background of a specimen instead
Differentiate Prokaryotic and Eukaryotic Flagella
What is an H antigen?
What is taxis?
Eukaryotic flagella move in a wave motion and anchored in the plasma membrane.
Prokaryotic Flagella rotate.
Flagellin is the protein subunit of the flagellum that carries H-antigen specificity.
Can be used in the detection and identification of different serotypes of flagellar bacteria
Flagella allow bacteria to move toward or away from stimuli
Outline the three ways that ATP is generated
Substrate Phosphorylation: ATP is generated from phosphorylation of ADP.
Oxidative Phosphorylation: Electrons are transferred from organic compounds to one group of electron carriers, electrons then are passed through a series of different electron carries to molecules of O2.
Photophosphorylation: Through the use of light ATP is generated from ADP, and Pi
Assume you inoculated 100 facultatively anaerobic cells onto nutrient agar and incubated the plate aerobically. You then inoculated 100 cells of the same species onto nutrient agar and incubated the second plate anaerobically. After 24 hours, which plate would have more growth?
both plates would be the same. Most facultative anaerobes are aerotolerant meaning that they would make a significant amount of ATP with or without O2
Which scientist discovered that DNA can be transferred from one bacterium to another
Lederberg and Tatum
What type of microscope would you use to visualize the internal structures of a an animal cell?
TEM -animal cells are around 10micrometers in diameter. Scanning electron microscopy can only
see external features because electrons cannot penetrate the cell, thus the cell must be
sectioned and prepared for transmission electron microscopy to see the internal structures such as organelles.
Compare and contrast gram (+) cell wall components and gram (-) cell wall
both have a plasma membrane and peptidoglycan in their cell wall, neither have a nucleus or membrane bound organelles
gram (+) have thick peptidoglycan in their cell walls along with teichoic acids and lipoteichoic acids
gram(-) have thin peptidoglycan, lipopolysaccharide, Lipid A, an outer membrane and periplasmic space
Identify the functions of pentose phosphate and Enter- Doudoroff pathway.
Pentose Phosphate: Operates with glycolysis and provides a means for the breakdown of five carbon sugars, pentose and glucose. NADPH, NUCLEIC ACID, E. FACEALIS.
Enter- Doudoroff pathway: Does not involve glycolysis
Production of 2 NADPH, and 1 ATP.
A prokaryotic cell hitched a ride to Earth on a space shuttle from some unknown planet. The organism is a psychrophile, an obligate halophile, and an obligate aerobe. Based on the characteristics of the microbe, describe the planet.
planet is very cold, salty and has oxygen
Was John Needham's boiled broth experiment an argument for biogenesis or spontaneous generation?
Spontaneous generation
Describe the relationship between acids, bases, and salts, and explain how the pH scale is
used to measure acidity and basicity.
Acids are substances that increase the concentration of hydrogen ions (H+) when
dissolved in water, such as HCl. Bases are substances that increase the concentration of
hydroxide ions (OH-) when dissolved in water and absorb H+ ions, such as NaOH. A salt
is a combination of a cation and anion, neither of which is H+ or OH-, such as NaCl. The
pH scale measures the amount of H+ ions in an aqueous solution. Neutral pH is defined as
7.0 where the amount of H+ ions and OH- ions are equal; this is the pH of pure water.
Acids lower pH values; values below 7 are considered acidic and lower numbers are
more acidic than higher numbers. Bases raise pH value; values above 7 are considered
basic and higher numbers are more basic than lower numbers. The pH scale is a
logarithmic scale, so each whole number step pH represents a tenfold change in acidity or
basicity.
Antibiotics such as penicillin interfere with the ability of bacteria to synthesize cell walls.
Explain why cell walls are a good target for a useful antibiotic
Because human cells do not have peptidoglycan in their cell walls, an antibiotic that affects peptidoglycan
can harm bacterial cells with less risk of damage to human cells
In an isotonic environment, a bacterial cell can survive without a cell wall and therefore
penicillin would be less effective than in a hypotonic environment.
Contrast fermentation and respiration in terms of electron donor, electron acceptor, type
of ATP production, and relative number of ATP produced.
Respiration uses separate electron donors and acceptors. For example, organic carbon in
the form of glucose can be the electron donor and oxygen the electron acceptor.
Fermentation uses organic molecules as both electron donors and aceptors in stepwise
fashion in order to regenerate NAD+. For example, in lactic acid fermentation, glucose is
oxidized to pyruvic acid, which is then reduced to lactic acid. Fermentation uses
substrate level phosphorylation to generate relatively few ATP, while respiration uses
both substrate level and oxidative phosphorylation to generate more ATP.
Flask A contains yeast cells in glucose–minimal salts broth incubated at 30°C with aeration. Flask B contains yeast cells in glucose–minimal salts broth incubated at 30°C in an anaerobic jar. The yeasts are facultative anaerobes.
Which culture produced more ATP?
Which culture produced more alcohol?
Which culture had a shorter generation time?
Which culture had the greater cell mass?
Flask A
Flask B
Flask A
Flask A
Explain the significance of Pasteur's S shaped flask
The shape prevented contamination and demonstrated the role of airborne microorganisms in the growth of life forms in nutrient-rich liquid media. This founded modern microbiology, improved aseptic technique, and demonstrated germ theory
You have a mixed culture of prokaryotes that you are studying. Which component of the plasma membrane would you tag to distinguish between archaea and bacteria
ethers
Tetracycline is an antibiotic that targets ribosomes which would stop the cell from producing its proteins, killing the pathogen. How is it that tetracycline does not kill human cells.
Prokaryotes have 70s ribosome and eukaryotes have 80s
Contrast fermentation and respiration in terms of electron donor, electron acceptor, type
of ATP production, and relative number of ATP produced.
Respiration uses separate electron donors and acceptors. For example, organic carbon in
the form of glucose can be the electron donor and oxygen the electron acceptor.
Fermentation uses organic molecules as both electron donors and acceptors in stepwise
fashion in order to regenerate NAD+. For example, in lactic acid fermentation, glucose is
oxidized to pyruvic acid, which is then reduced to lactic acid. Fermentation uses
substrate level phosphorylation to generate relatively few ATP, while respiration uses
both substrate level and oxidative phosphorylation to generate more ATP
Compare and contrast the spread plate method and the pour plate method of doing plate
counts. Also describe which group of organisms would not be quantifiable in the pour
plate method but would still be observed in the spread plate method
The pour plate method involves mixing the bacterial sample with liquefied agar, then
pouring this mixture into a petri dish, allowing it to cool, and incubating to allow for
bacterial growth. The spread plate method involves spreading a bacterial sample onto an
already cooled and solidified agar medium. One benefit to the pour plate method is that
larger volumes of cells can be dispensed, whereas large liquid volumes dispensed on the
surface of agar plates is often impractical. Many cells, especially psychrophiles and some
mesophiles, cannot withstand the warm temperature of molten agar (~50°C) and therefore
must be spread on top of an agar plate