Bio 226- Exam 1

Which of the following in not a distinguishing characteristic of prokaryotic cells?

They lack a plasma membrane

Which cell type produces primarily endotoxins?

E. Coli

Which of the following statements about gram negative cell walls is false?

They have a thick layer of peptidoglycan

Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5% NaCl?

Water will move out of the cell

Which term describes a flagella arrangement that has many flagella surrounding the cell?

Peritrichous

If you have a compartment divided by a membrane, there are 8 molecules of SUCROSE on one side of the membrane and 10 molecules if FRUCTOSE in the other side of the membrane. When will the solution reach equilibrium for FRUCTOSE?

When there are 5 molecules of fructose on each side

The function of pili is for

transfer of genetic material

Which is the best explanation for why antibiotics that inhibit protein synthesis such as tetracycline, in general don't harm the host's cells, but inhibit bacterial cells?

Eukaryotic cells have 80s ribosomes while bacteria have 70s ribosomes

What type of molecules cannot pass across the plasma membrane?

proteins

Which of the following external prokaryotic structures are considered to be a be virulence factors?

Glycocalyx and fimbriae

Cocci that are arranges in grape-like clusters are referred to as

Staphylococci

Which of the following statements is NOT true about Gram negative bacteria?

high resistance to drying

After performing the gram stain procedure you realize that you decolorized with water instead of 95% EtOH. What color would the cells appear under the microscope when observed?

both gram positive and negative would be purple

"Bonus" genes that may be helpful for bacteria to survive in certain environments are often found on small. circular extra chromosomal DNA known as

plasmids

Which of the following statements does NOT explain why gram positive cells retain the primary dye during gram staining?

alcohol dissolves the LPS layer

Name a genus of bacteria that form endospores

bacillus

Which cell type is more susceptible to anionic detergents?

gram positive

Which of the following statements is NOT true about facilitated diffusion?

requires ATP

Which of the following is NOT found in the cell wall of gram positive bacteria?

lipid A

Bacteria that look like "comm" curved rods are called

vibrios

If you wanted to kill a bacterial cell, which solution would be more likely to be lethal by osmotic lysis?

pure water

Which would be a preferred food source to produce ATP?

something highly reduced

Which of the following uses CO2 for carbon and H2 for energy?

chemoautotroph

A strictly fermentative bacterium produces energy in the form of ATP by

glycolysis only

You are trying to culture Bacillus, Clostridium, and Streptococcus. Which one will grow faster?

Bacillus

The intermediate step in metabolism as pyruvic acid is converted into Acetyl CoA is responsible for generating how many ATP via oxidative phosphorylation?

6

How many ATP are generated from the complete oxidation of 1 molecule of glucose during prokaryotic aerobic respiration via the production of NADH by oxidative phosphorylation in the electron transport chain?

30

If a bacterial cell was unable to make Fructose-6-Phosphate. Which of the following would the cell be unable to beat?

Cell Wall

If the Pentose Phosphate Pathway was not operational in a bacterial cell, a major consequence for the cell would be that it could not synthesize which of the following macromolecule?

nucleic acids

If a hypothetical bacteria had a non functional FMN that can pass electrons, but can no longer pump protons. How many ATP could it produce from 1 molecule of glucose?

28

According to chemiostatic mechanism, ATP is generated when

protons are moved across a membrane

Which of the following molecules is further oxidized by directly feeding into the energy conserving stage of glycolysis?

glyceraldehyde-3-Phosphate

The "bubbles" in alcoholic beverages are caused by the production of?

CO2

Which of the following steps in the Kreb's Cycle is the only step that generates FADH2?

succinic acid to fumaric acid

Where is the electron transport chain found in eukaryotic cells?

mitochondrial membrane

Which statement best explains why FADH2 yields less ATP per molecule than NADH in oxidative phosphorylation?

it feeds into the ETC chain at a lower energy level at CoQ

If a prokaryotic organism was unable to utilize its electron transport chain to carry out oxidative phosphorylation how many ATP could it produce from complete oxidation of 1 molecule of glucose?

4

If you wanted to make a nice sweet tasting rye bread, which of the following organisms would you use?

lactobacillus

A decrease in the pH of the medium would be expected to ________ chemiosmosis

increase

In the Kreb's Cycle, the pyruvic acid derivatives are _____ and the co-enzymes become ________

oxidized;reduced

What occurs during fermentation?

fermentation regenerates NAD+ as pyruvic acid is converted to lactic acid or ethanol

If a mutant bacteria could not convert Pyruvic acid to Acetyl CoA, but still had a functional ETC, how many ATP would the organism be able to make form 1 molecule of glucose?

8

All of the following are direct methods to measure microbial growth except

measuring glucose consumption

Which organism lacks the enzymes catalase and superoxide dismutade needed to neutralize harmfyl forms of oxygen?

clostridium

An aerotolerant anaerobe growing in a tube of Thigylcollate media would be expected to be found where in the tube?

evenly throughout the tube

IF you were working with a salmonella spp in the lab, what type of bio safety level precautions would need to be implemented?

BSL 2

AN overnight culture is serially diluted and then plated on BHI agar. You do 5 : dilutions and then plate ml of bacteria from each dilution tube. The first and second plates are TNC. The third plate has colonies counted, the fourth plate has 93 colony forming units and the fifth plate has 15 colonies. What is the titer?

93 x 10,000 CFU/ml

Which bacteria would you expect to grow aerobically on PEA?

bacillus

Which of the following chemical requirements together make up approximately 4% of the dry weight of a bacterial cell?

sulfur and phosphorus

Which of the following could be a possible therapy to treat biofilms?

lactoferrin

During which growth phase will gram positive bacteria be most suspectible to penicillin?

log phase

Where is a capnophile most likely to be found?

throat

The calculation of the most probable number uses lactose broth because

it's calculating the number of normal flora present in the sample

In the microbial succession of milk after microorganisms like streptococcus and Lactobacillus have fermented the milk sugar lactose, what microorganism do you suspect to will increase in number?

saccharomyctes

What is the purpose of doing the streak plate method?

the purpose is to dilute out and seperate the bacteria present to get isolated

At which temperature would a mesophile be at its optimal growth rate?

37 celsius

Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt?

halophiles

You observe a purple colonies from an organism streaked on EMB. What organism do you suspect?

enterobacter

Which of the following solutions would cause plasmolysis?

9& NaCl

A number of colorless colonies appear on a plate of MacConkey's agar after streaking a stool sample. What is your interpretation?

A fecal pathogen is suspected and needs to be further identified.

If you were doing a throat screen, what toe of hemolysis would you look for to determine if your patient has a strept throat?

beta hemolysis

Cells that are in the log phase of growth would be expected to be at their _____ generation time?

minimum

If you were trying to select for Staphylococcus from a culture containing both Staphylococcus and Streptococcus, which of the following media would you use?

MSA agar

The lowest temperature at which all cells in a culture are killed in 10 minutes is the

thermal death point

Which of the following affects the elimination of bacteria from an object?

all of the above

Which of the following organisms would be expected to survive pasteurization?

thermophiles

Which of the following bacteria have an innate resistance to penicillin?

mycoplasma pneumoniae

Bacterial populations die at a constant logarithmic rate, therefore a one log decrease would result in what % of the population killed?

90%

Which of the following treatments would achieve sterilization?

both are equivalent treatments

Which of the following could be used to sterilize surgical instruments wrapped in a plastic wrapper?

gamma rays

Foods are preserved with all of the following except

biguanides

lowering the microbial counts on eating utensils is referred to as

sanitization

Broad spectrum antibiotic that inhibits protein synthesis, is bacteriostatic and commonly used in animal feed

tetracycline

The effectiveness of chemical disinfectants has historically been compared to that of which of the following?

phenol

If you didn't have an autoclave at home, what could you use to sterilize baby bottles?

pressure cooker

Which of the following is most effective for sterilizing mattresses and plastic petri plates?

ethylene oxide

Which of the following organisms would be the most difficult to disenfect?

bacillus cereus

Which treatment would be expected to be more germicidal?

high temperature

The goal of commercial sterilization protocols is to rid caned foods of

clostridium botulinum endospores

Which of the following is added to ground beef to prevent endospore germination and help retain the meats red color?

nitrates

Hydrogen peroxide is a good disinfectant, but a poor antiseptic

true

Which disinfectant would be the most effective on both endospores and mycobacteria?

gluteraldehyde

Which of the following cannot be used for this disinfection of water?

bisphenols

Which of the following disinfectants works by "oligodynamic action"?

heavy metals

Microwaves kill by heat and are very effective as an antimicrobial

false

what cell is not in a membrane?

prokaryotic

Which cell has histones and organelles?

eukaryotes

Which is larger eukaryotes or prokaryotes?

eukaryotes

rod shaped bacteria

bacillus

spherical shape bacteria

coccus

means single shape

monomorphic

means irregular morphology

pleomorphic

function if flagella

motility

function of fimbriae

allow attachment

semi rigid structure giving characteristic cell shape

cell wall

NAG and NAM makes this up

peptidoglycan

which cell wall has a thick peptidoglycan?

gram positive

smallest known bacteria that can grow and reproduce outside a host cell

mycoplasmas

digests disaccharide in peptidogylcan

lysozome

inhibits peptide bridges in peptidoglycan

penicillin