Unit 1: MicroBio

Consider the reaction AB-> A + B. What is the product of this reaction?

A and B.

Which statement does NOT describe a catalyst?

A catalyst will decrease the rate of a reaction.

Why is visualization not sufficient to properly identify bacteria?

Bacteria have a limited set of shapes and many unrelated bacteria share the same shape.

Why can't prokaryotic species be defined as a group of similar organisms that could sexually reproduce together?

Bacteria reproduce asexually.

Choose the TRUE statement(s) about binary fission in prokaryotic cells.

Binary fission frequency differs between species and is affected by envriomental conditions. Binary fission results in offspring, which are genetically identical to the parent cell. Binary fission is a type of asexual reporduction that is simpler than mitosis.

Which of the following is (are) organic?

CH4. C6H12O6.

Which of the biomolecules is incorrectly matched with its building block?

Carbohydrate: polysaccharide

Select all of the TRUE statements regarding biomolecules and their building block monomers.

Carbohydrates are built from monosaccharides. Proteins are built from amino acids.

Using the periodic table of elements, select all of the TRUE statements about carbon.

Carbon's atomic number is 6. One carbon atom contains 6 protons and 6 neutrons.

Choose the FALSE statement(s) about biofilms.

Cells within a biofilm are described as "planktonic".

Put the following steps of bacterial replication in the correct order starting from a parent cell.

Chromosome replication. Cell elongation. Septum formation. Separation of daighter cells.

Which of the following does NOT represent a shape or arrangement that a prokaryote can assume?

Clusters of bacilli form a Staph arrangement.

BLANK are molecules made up of more than one type of element.

Compounds.

Choose the TRUE statement(s) about equilibrium.

Equilibrium is not a static situation where the reaction just stops. By definition, equilibrium is a term that mainly applies to reversible reactions. Reactions at equilibrium have the forward and reverse reactions occuring at the same rate.

Which of the following is the correct way to type a scientific name?

Escherichia coli (italicized)

A glycoprotein

is a type of peripheral protein above that can be used as a receptor or in enzymatic functions.

The primary structure of a protein

is the linear sequence of amino acids which are held together by peptide bonds and is dictated by genetic sequence and is unique to that protein and lays the foundation for all higher order structure of that protein.

Activation energy

is the minimum amount of energy needed to get a reaction started and is due to the necessity of collisions between reactants which have enough energy and with the reactants properly oriented and can be lowered by catalysts such as enzymes in biochemical reactions.

The goal of the streak plate technique is to

isolate a pure culture for study from a single colony.

What is meant by light rays being divergent?

it is spreading out.

Immersion oil is required to BLANK.

minimize scattered light when the high-powered lens is used.

Once equilibrium is reached,

molecules move, but there is no NET movement in a particular direction.

Which of the following is NOT a microorganism?

mosquito

Minor mutations and/or gene transfers may lead to the development of a new BLANK and is a term that describes very closely related organisms that are slight genetic variants of one another.

strain

Which of the following arrangements is sometimes referred to as having a beads-on-a-string appearance?

streptococci

Integral proteins are mostly involved in

transport function.

The composition of the cell wall allows for the expansion and contraction of the cell wall in response to the gain or loss of water from the cell.

False

How does the Gram staining procedure differentiate between Gram-negative and Gram-positive bacteria?

It differentiates between Gram-positibe and Gram-negative bacteria based on cell wall composition.

Why is the unknown in this example not Pseudomonas?

It ferments lactose.

What is a hallmark of passive transport across cell membranes?

It occurs along an electrochemical gradient, and may invoolve the use of transport proteins.

Which of the following statements regarding active transport is false?

It powers the diffusion of water across the cell membrane.

How would the results be different if this organism was Salmonella?

It would produce hydrogen sulfide.

What is the role of lensese in microscopy?

Lenses focus either the light or electrons to create a magnified image of a specimen.

Choose the TRUE statement(s) about prokaryotic cells.

Most of the prokayote's nutrients are obtained through diffusion. All prokaryotes lack a membrane-bound nucleus and organelles. All prokaryotes are unicellular organisms.

How long does it take for the daughter cells to initiate or start the next round of replication?

No time is required- they are ready to divide immediately after DNA replication and separation of the daughter cells is complete if conditions are right.

Why are most prokaryotic cells small?

Nutrient diffusion is most efficient for smaller cells.

The ability of certain bacterial cells to take on different cell shapes is known as

Pleomorphism.

Which of the following would NOT move freely across the cytoplasmic membrane?

Positively charged hydrogen ions.

Which particle is described incorrectly?

Proton: Found in shells orbiting the nucleus.

Which of the following is (are) mismatched?

Pure culture: diverse colonies evident Streak plate technique: broth culture

Choose the FALSE statement(s) about acids and bases.

Pure water has more H+ ions than OH- ions. If an acid is added to an acidic solution, the pH will increase.

What color would Gram-positive bacteria be at the end of Gram staining if the decolorizing step was left out of the procedure?

Purple

What step of binary fission is the reason for genetically identical daughter cells?

Replication of the bacterial chromosome.

BLANK is the ability to distinguish two distinct points as separate.

Resolution.

Which of the following types of microscopy would be the best to provide information about 3-D surface structures of a virus?

Scanning electron microscopy.

Which level of protein structure can involve hydrogen bonds?

Secondary and tertiary.

How is simple diffusion different from other types of passive transport?

Simple diffusion does not require a permease.

A positvely charged sodium ion

would require the use of integral protein channels to pass through a cell membrane.

What test result indicates that the unknown can utilize citrate as its sole carbon source?

The medium turns blue.

What is the role of the ocular lens?

To recreate the image in the viewer's eye.

Starting with three cells, how many cells would result from three rounds of replication?

Twenty-four.

How many answers are there to a question in a dichotomous key flowchart?

Two

What results when a single bacterium reproduces?

Two genetically identical daughter cells.

Which of the following lipids tends to be liquid at room temperature?

Unsaturated lipids.

BLANK are usually found in an atom's outermost shell and tend to participate in chemical reactions.

Valence electrons.

Pure water is defined by

a neutral pH of 7 and an equal number of H+ and OH- ions.

Cell shape is determined by which of the following?

cell wall and cytoskeleton components

Which of the following characteristics would NOT be used to aid in classifying a newly discovered bacterial species?

cellular size.

Normal microbiota are responsible for all of the following EXCEPT

controlling epigenetic expression

Which of the following is NOT one of the four main groups of biomolecules?

electrolytes.

All of the following are or can be produced by microbes EXCEPT

electronics like computer memory

All of the following are examples of inclusion bodies in prokaryotic cells except BLANK.

endospores.

In biological systems, the energy released by BLANK reactions is used to fuel BLANK reactions.

exergonic; endergonic

Which of the following molecules would be blocked by a cell membrane?

Ions.

How many questions are needed in this dichotomous key to determine if the unknown is Bacteroides?

Three

What is the composition of the peptidoglycan layers found in the cell wall of bacteria?

short amino acid chaings, NAG, NAM and some lipid proteins.

Which of the following is NOT a step in bacterial cell division?

Disapperance of nuclear envelope.

Which of the following best describes the tertiary structure of proteins?

3D globular structures stabilized by covalent disulfide bridges.

Select the TRUE statement(s) about a scientific name for an organism.

A scientific name for an organism consists of two names. An organism's name may refer to its discoverer, the organism's shape and/or arrangement, or other distinct traits.

Choose the TRUE statement(s) regarding the pH scale.

A solution's pH decreases as H+ concentration increases. A solution with a pH of 6 has an H+ concentration that is tenfold higher than that of a solution with a pH of 7. Acidosis is a pathological situation in which the body has lower than normal blood pH.

Which of the following is(are) mismatched?

Acid-fast stain: turns acid-fast cells blue. Gram stain: turns Gram-negative cells purple.

Choose the TRUE statement about atoms.

An atom is the smallest unit of an element. The nucleus of an atom contains neutrons.

Why do electron microscopes have a better resolution versus light microscopes?

An electron beam has a wavelength of about 1 nm, and resolution improves with smaller wavelengths.

Select the TRUE statement(s) about ionic bonds.

An ionic bond requires the transfer of electrons from one atom to another. An ionic bond is an electrostatic force that exists between cations and anions.

Choose the TRUE statement(s) about ions.

Anions result when atoms gain and electron. Cations have more protons than electrons.

Why is a specimen smaller than 200 nm not visible with a light microscope?

Anything smaller than 200 nm cannot interact with visible light.

Why aren't Archaea discussed as much as bacteria?

Archaea haven't been linked to human diseases.

Choose the characteristics that separate the archaea from another prokaryotic cell.

Archaea lack true peptidoglycan in their cell walls. The cytoplasmic membrane lipids of archaea have branched or ringform hydrocarbon chains. ​

Choose the FALSE statement about aseptic culturing techniques.

Aseptic technique is unnecessary in most labs because the majority of microbes are not pathogenic.

The pictured molecules both contain six carbon atoms, twelve hydrogen atoms, and six oxygen atoms. However, these atoms are arranged differently in each molecule. What are these molecules called?

Isomers.

Which of the following statements about bright field microscopy are TRUE?

Bright field microscopy is the simplest and most common form of microscopy.

Organisms depend on BLANK, which are compounds that stabilize pH by absorbing or releasing H+ ions.

Buffers.

How does water enter and exit a cell?

By simple diffusion or by use of an intergral transport protein.

BLANK are atoms with the same number of protons but a different number of neutrons.

Isotopes.

How are DNA and RNA different?

DNA is usually double-strained, while RNA is usually single-strained. Deoxyribonucleotides make up DNA, while ribonuclotides make up RNA.

Assume you are a pediatric patient suffering from a severe form of infectious diarrhea. Which of the following condition(s) is/are most likely to develop as a direct result of diarrhea?

Dehydration. Electrolyte imbalance.

Choose the TRUE statement(s) about micelles.

Detergents can form micelles. Micelles contain both water-loving and water-fearing regions. Micelles are made by amphipathic molecules.

Choose the FALSE statement about cellular transport mechanisms.

Diffusion is the passive movement of substances from areas of low concentration to areas of high concentration.

Choose from the following statements the ones that correctly discuss reproduction using binary fission in a bacterial cell.

Each daughter cell is an exact copy of the other, both genetically and morphologically. Due to the stretching of the cytoplasmic membrane, both cells will contain a complete genome.

BLANK are formed when ionic compounds dissolve in solution and have a role in regulating blood volume.

Electrolytes.

Choose the TRUE statement(s) about activation energy.

Enzymes lower the activation energy of a reaction. Activation energy is teh minimum amount of energy needed to start a reaction.

A cell wall is a requirement for all living bacteria.

False.

Bacterial flagella have a biological motor that spins within the cell wall and is powered by ATP. This allows flagella to spin in a whiplike motion to propel the bacterium.

False.

If you begin with six cells, how many cells would you have after three rounds of division?

Forty-eight cells.

The first question in this dichotomous key addresses

Gram stain differences.

BLANK bacteria lack an outer menmbrane, have a thick layer of peptidoglucan, contain teichoic acid, and lack mycolic acid.

Gram- positive.

Choose the MISMATCHED pairing(s).

Hydrophilic: Oil. Hydrophobic molecules: Polar

Choose the FALSE statement regarding prokaryotic plasma membranes.

Ions and large polar substances can diffuse through the plasma membrane without assistance.

Which type of bond links amino acids together to form a protein's primary structure?

Peptide bonds.

Choose the TRUE statement(s) about prokaryotic external appendages.

Pili allow for adhesion, movement, and aid in gene transfer through conjugtion. Flagella allow for motility. The glycocalyx promotes adhestion and interferes with phagocytosis.

BLANK bacteria can create sticky communities called BLANK, which are made up of single microbial species.

Plaktonic; biofilms.

Choose the TRUE statement about the Domain Bacteria.

The Domain Bacteria is made up of prokaryotes and likely originated 3.8 billion years ago.

What happens to the light rays when they hit the specimen?

The are reflected, refracted or absorbed by the specimen.

What will happen to a cell that is placed in a solution containing a high concentration of sugar, a molecule that cannot pass across the cell membrane?

The cell will lose its interior water, causing it to shrivel up and possibly die.

Considering the procces of osmosis, what will occur if a bacterial cell is pit into a hypotonic solution.

The cell will take on water and may lyse if its cell wall is damaged.

What enables the copied chromosomes to seperate during binary fission?

The chromosomes are attached to different parts of the cell membrane, which elongates and thus separates the chromosomes.

Why is no energy required in passive transport?

The concentration gradient drives the movement.

How is fermentation of lactose detected?

The drop in pH turns the indicator dye yellow.

A feature of many of the isotopes that are used in the field of medicine is that the isotopes are radioactive.What does this mean?

The nucleus of the isotope is unstable and breaks down over time.

In a typical brightfield microscope (seen in animation), at which point does magnification begin?

The objective lens.

Which of the following is NOT one of Koch's postulates of disease?

The organism may cause a different disease in some infected individuals.

What would happen if the septum did not form during binary fission?

The parent cell would now have two copies of the chromosome.

Choose the FALSE statement(s) about the simple staining technique.

The simple staining method uses a single acidic dye that stains the slide background.

BLANK is used to isolate individual colonies on a solidified agar surface.

The streak plate method.

Which of the following is an example of bioremediation?

The use of Marinobacter species to degrade oil.

Why are flowcharts useful for dichotomous keys?

They allow the researcher to visualize relationships between different bacteria.

Which statement is TRUE about carbohydrates?

They are a component of the cell wall of different types of organisms.

What is the hallmark of dichotomous keys?

They consist of a series of paired statements, in which only one statement of each pair applies to a given organism.

What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass?

They have both hydrophilic and hydrophobic regions.

How is osmosis different from simple diffusion?

Water movement is driven by the concentration of solutes rather than is own concentration.

Which type of lipid is incorrectly matched to is description?

Wax: Refers to any lipid which is solid at room temperature.

When do opportunistic pathogens tend to cause disease?

When the host is weakened.

Which reaction has X and Y as reactants?

X + Y -> XY

Nonspecific permeases

allow a variety of molecules to cross the cytoplasmic membrane.

Biochemical tests..

are the main methods used to identify unknown bacteria.

Hydrophobic molecules move across a membrane

by passive transport directly across the membrane.

Prokaryotic cells house a single ciruclar chromosome in their BLANK.

nucleoid region.

Compared to a solution with a pH value of 4, a solution with a pH value of 2 has BLANK H+ ions.

one hundred times as many

The type of bond which links the amino group of one amino acid to the carboxyl group of another amino acid is called a(n)

peptide bond.

Which of the following does NOT contribute to shifts in our normal microbiota?

proper hand-washing technique