Assignment 3

Peptidoglycans are composed of sugars and _____. amino acids nucleic acids lipids teichoic acids

Amino acids. Amino acids combine to form the peptide portion of the peptidoglycan

The peptidoglycan cell wall of bacteria is most analogous to _____. an impenetrable brick wall a rain coat a chain-link fence a sugary candy shell

A chain-link fence The peptidoglycan cell wall is meshlike, allowing for easy passage of ions, amino acids, and nutrients and maintaining structural integrity.

Which of the following would contain teichoic acids? a pseudomurin cell wall a Gram-negative cell wall the glycocalyx a Gram-positive cell wall

A gram-positive cell wall

Why is ATP necessary for active transport?

ATP provides energy to transfer material against its concentration gradient

Bin 1 - Image of a single round bacterium. Bin 2 - Image of a single rodishaped bacterium. Bin 3 - Image of a cluster of round bacteria. Bin 4 - Image of a string of rodishaped bacteria. Bin 5 - Image of a vibrio (commaishaped) bacterium. Bin 6 - Image of a corkscrewishaped spirochete bacterium. Drag the descriptive terms to the pictured bacterial shapes.

Bin 1: cocci Bin 2: bacilli Bin 3: staphylococci Bin 4: streptobaccili Bin 5: vibrio Bin 6: spirochete

Amoxicillin is an antibiotic that inhibits the formation of peptide cross-links. Amoxicillin, therefore, would most likely inhibit the growth of __________.

Both gram-positive and gram-negative organisms

How does water enter and exit a cell? By simple diffusion or by use of an integral transport protein By use of a peripheral transport protein By simple diffusion across the membrane By use of an integral transport protein

By simple diffusion or by use of an integral transport protein

Which of the following is NOT a characteristic of a eukaryotic cell? presence of a nuclear envelope presence of membrane-bound organelles can undergo transcription and translation simultaneously contain chromosomes composed of DNA and histones

Can undergo transcription and translation simultaneously

Which of the following is classified as a nonmembranous organelle of eukaryotic cells? centriole peroxisome mitochondrion Golgi body endoplasmic reticulum

Centriole

The structural framework in a cell is the extracellular matrix. endoplasmic reticulum (ER). cytoskeleton. endomembrane system. plasma membrane.

Cytoskeleton

A patient is infected with Gram-negative bacteria and is experiencing only mild symptoms. When the patient is given an antibiotic causing lysis of the bacterial cells, he suddenly experiences an increase in inflammation and fever, as well as the formation of blood clots. What explanation best describes what happened?

The lysis of the cells releases lipid A from the lipopolysaccharide layer. Lipid A is known to cause inflammation, fever, and blood clots.

Why is no energy required in passive transport?

concentration gradient drives the movement

Which of the following is NOT a function of the Streptococcus pyogenes cytoplasmic membrane? diffusion active transport endocytosis selective permeability

endocytosis This is a function of eukaryotic cytoplasmic membranes and is not found in bacterial membranes.

Endocytosis and exocytosis are means of transport used by bacteria. eukaryotes. archaea. all prokaryotes. nothing; no cells use both processes.

eukaryotes

Which of the following statements about bacterial flagella is true? Flagella can rotate 360 degrees. Flagella work by undulating. Bacteria can only rotate flagella clockwise. Bacteria can only rotate flagella counterclockwise.

flagella can rotate 360 degrees

Which of the following is part of the endomembrane system? cytoskeleton mitochondria Golgi apparatus flagellum ribosomes

golgi apparatus the endomembrane system includes the ER, golgi apparatus, lysosomes, and vesicles. It manufactures, processes, and transports lipids and proteins. The golgi apparatus processes and packages porteins.

amphitrichous flagella

have a single flagellum on each end

A glycoprotein

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

Bacteria of the genus Mycoplasma lack cell walls. What sort of environment do they require for survival?

isotonic

lipid A is a component of

lipopolysaccharides *this is only in gram-NEGATIVE bacterial cell walls*

Which of the following organelles breaks down worn-out organelles? Golgi apparatus mitochondria lysosomes smooth endoplasmic reticulum (ER) rough endoplasmic reticulum (ER)

lysosomes

What carries instructions for making proteins from the nucleus into the cytoplasm?

mRNA

Where in a cell is ATP made? chloroplasts nucleus ribosomes mitochondria lysosomes

mitochondria

Penicillin is used to treat Streptococcus pyogenes infections. Treatment is successful when the pathogen is killed, but the medication does not harm the host cells. Penicillin disrupts the peptide bridges between NAM units. This results in __________.

Damage to the bacterial cell wall. Gram-positive bacteria have thick layers of peptidoglycan as part of their cell wall. These layers are stabilized by peptide bridges between NAM units. Without these cross bridges, the cell wall "crumbles".

Lipid-soluble molecules would be expected to cross the cytoplasmic membrane by which of the following processes? group translocation diffusion facilitated diffusion active transport osmosis

Diffusion

Which of the following statements concerning osmosis is FALSE? Osmosis stops when the system reaches equilibrium. Cells placed in hypotonic solutions will gain water. Osmosis requires a selectively permeable membrane. During osmosis, water crosses to the side of the membrane with a lower solute concentration. Crenation results when cells are placed in a hypertonic solution.

During osmosis, water crosses to the side of the membrane with a lower solute concentration

A bacterial cell stains positive with the acid-fast stain. Which of the following is FALSE? It has a cell wall that contains endotoxin. It will be difficult to stain this cell with the Gram stain. It may be a member of the genus Mycobacterium. It has a cell wall that contains waxy lipids.

It has a cell wall that contains endotoxin. Endotoxins are found in gram-negative cells, none of which are acid fast.

What is a hallmark of passive transport across cell membranes? It requires the use of ATP. It may involve the use of transport proteins. It occurs along an electrochemical gradient. It cannot occur without assistance from an integral membrane protein. It occurs along an electrochemical gradient, and may involve the use of transport proteins.

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

Which of the following statements regarding active transport is false? It requires the use of a transport protein. It requires ATP. It powers the diffusion of water across the cell membrane.

It powers the diffusion of water across the cell membrane

A bacterial cell possesses a glycocalyx. Which of the following is FALSE? It will be more pathogenic. It will be engulfed more quickly by defensive cells of the host. It will be less likely to dry out. It will be able to attach to surfaces.

It will be engulfed more quickly by defensive cells of the host

Which of the following would NOT be expected to be present in a biochemical analysis of an archaeal cell? phospholipids peptidoglycan ribosomes membrane proteins

Peptidoglycan

once equilibrium is reached...

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

which of the following types of bacterial cells would have only a single flagellum?

monotrichous

which of the following types of bacterial cells would have flagella located at only one end of the cell?

monotrichous and lophotrichous

taxis

movement towards or away from a stimulus

PHB is NOT associated with which of the following words? ribosome inclusion biodegradable plastic

ribosome

the basal body is comprised of which structural components of flagella?

rod and rings

as a bacterium approaches a food source, one would expect...

runs to become more frequent

What is the composition of the peptidoglycan layers found in the cell wall of bacteria? Pick the answer that lists the composition of the bacterial cell wall

short amino acid chains, NAG, NAM, and some lipid protein

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

simple diffusion does not require a permease

Where are lipids made in the cell? ribosomes Golgi apparatus rough endoplasmic reticulum (ER) smooth endoplasmic reticulum (ER) mitochondria

smooth ER

What type of transport uses two transport proteins?

symport

Which of the active transport types employs diffusion?

symport

which type of active transport protein moves two molecules into the cell at one time?

symport

A bacterial cell is placed in distilled water. Which of the following will happen? There will be no net gain or loss of water in the cell. The cell will gain water. The cell will lose water. The cell will shrink.

the cell will gain water

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

tumbles occur when

the flagella rotate clockwise

peritrichous flagella make a run when

the flagella turn counter clockwise and become bundled

Nadia has an infection caused by Streptococcus pyogenes, which has a Gram-positive cell wall. What distinguishes Gram-positive bacterial cell walls from Gram-negative bacteria cell walls?

the presence of teichoic acids Teichoic acid is unique to Gram-positive organisms and anchors the peptidoglycan layer to the cell membrane.

why are receptors on the cell surface necessary for bacterial movement?

the receptors sense the stimulus and send signals to the flagella

Hydrophobic molecules would enter a cell...

through integral transport proteins

Which transport protein employs transporters that move molecules only in one direction?

uniport and symport

Bacterial cell walls that are resistant to drying contain

waxes

A positively charged sodium ion...

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

Which of the following is NOT a membranous organelle within a eukaryotic cell? ribosome nucleus chloroplast endoplasmic reticulum

Ribosome

Archaeal flagella __________. rotate as bacterial flagella do grow by the addition of subunits at the tip do not contain a filament are powered by the flow of hydrogen ions across the membrane

Rotate as bacterial flagella do

Which of the following is NOT a basic process of life? sexual reproduction metabolism responsiveness growth

Sexual reproduction Not all living organisms reproduce sexually.

Periplasmic space

Space between the cytoplasmic membrane and the outer membrane of gram-negative bacteria -contains peptidoglycan and periplasm

Which of the following is NOT a component of eukaryotic cell walls? chitin silicates sterols cellulose

Sterols Sterols may be found in cytoplasmic membranes, but not in cell walls.

One chain of alternating NAGs and NAMs is connected to another chain via _____. enzymes tetrapeptides lipids teichoic acids

Tetrapeptides Tetrapeptides are composed of four amino acids and make up the "peptido" portion of peptidoglycan.

Bacterial flagella have a biological motor that spins within the cell wall and is powered by ATP. This allows the flagella to spin in a whiplike motion to propel the bacterium. Is this statement True or False? Choose the answer that you think is correct.

The biological motor that spins the flagella for bacterial propulsion is powered by the electron imbalance across the membrane that generates a gradient that the cell can harness for energy via proton motive force.

Eukaryotic ribosomes are composed of 50S and 30S subunits. True False

False Eukaryotic ribosomes are composed of 60S and 40S subunits. Prokaryotic ribosomes are composed of 50S and 30S subunits.

The short structures on the surface of the cell in the figure are cilia. True False

False. Pili

what structural part of bacterial flagellum is composed of flagellin?

Filament

positive phototaxis

bacterium moving towards a light source

Which of the following bacterial cell structures plays an important role in the creation of biofilms? fimbriae pili flagella glycocalyces both fimbriae and glycocalyces

both frimbriae and glycocalyces

pathogenic bacteria

can be identified and classified by differences in their flagellar proteins

Lipopolysaccharide (LPS)

-Makes up the outer leaflet of the outer membrane of gram-negative bacterial cell walls -union of lipid and sugar -lipid portion is called Lipid A; endotoxin a dead cell releases lipid A when the outer membrane disintegrates, and lipid A may trigger fever, inflammation, vasodilation, shock, and blood clotting in humans. ---so killing large numbers of gram-negative bacteria with antimicrobial drugs release large amounts of lipid A, which might threaten the patient more than the live bacteria itself.

Sodium and potassium ions need to be pumped simultaneously against their concentration gradients. Which one of the transport proteins would be most effective at this?

Antiport; transports two different molecules and in opposite directions

The hami of some archaea are used for which of the following processes? reproduction defense locomotion attachment

Attachment

If a eukaryotic cell suffers damage to its mitochondria, which of the following processes of life would be most immediately affected? reproduction responsiveness energy production growth

Energy production

Which of the following processes can be either specific or nonspecific depending upon the particular molecules that are transported? osmosis diffusion facilitated diffusion active transport

Facilitated diffusion

A cell wall is a requirement for all living bacteria. Choose True or False. True False

False

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. Choose True or False. True False

False

The filament and basal body are associated with which of the following external structures found in some bacterial cells? glycocalyx fimbriae pili flagella

Flagella

Porins are present in ______________bacteria because, in these organisms, molecules entering the cell must pass through an extra layer of ___________.

Gram negative; membrane

Place each attribute into the bin of the bacterial group it belongs to, based on whether the bacterium is a Gram-positive or a Gram-negative cell.

Gram positive: -teichoic acids -thick layer of peptidoglycan -single lipid bilayer membrane Gram negative: -thin layer of peptidoglycan -periplasmic space -lipopolysaccharides -dual lipid bilayer membranes

A periplasmic space is found in which of the following? Gram-negative cells only Gram-positive cells only both Gram-positive and Gram-negative cells neither Gram-positive nor Gram-negative cells

Gram-negative cells ONLY

The accumulation of glucose 6-phosphate inside a bacterial cell via phosphorylation of glucose is an example of

Group translocation

Which of the following molecules would be blocked by a cell membrane? Simple alcohols Water Ions Dissolved oxygen

Ions

Which of the following molecules is shared by both Gram-positive and Gram-negative organisms? lipid A lipopolysaccharide N-acetylmuramic acid lipoteichoic acid

N-acetylmuramic acid

When the nurse practitioner looked into Nadia's throat, she saw white spots on the tonsils. These were white blood cells attempting to fight off the infection. Which of the following statements explains a key difference between Nadia's white blood cells and the Streptococcus pyogenes infecting her throat?

Nadia's white blood cells have a nucleus, while the Streptococcus pyogenes do not. *Nadia's white blood cells are eukaryotic, while the Streptococcus pyogenes are prokaryotic. The distinctive feature of prokaryotic cells is that they do not have a nucleus.*

Which of the following statements accurately describes a difference between gram-positive and gram-negative cells? Gram-positive cells contain less peptidoglycan than gram-negative cells. Gram-negative cell walls contain teichoic acids. Only gram-negative cells have a lipopolysaccharide (LPS) layer. Only gram-positive cells have peptidoglycan that is made of a carbohydrate backbone.

Only gram-negative cell walls have a lipopolysaccharide (LPS) layer

The region between the outer and inner membranes of a Gram-negative bacterial cell is known as the __________, and it is the location of enzymes that assemble peptidoglycan

Periplasmic space The periplasmic space is an area surrounding the bacterial cytoplasmic membrane

The process of bringing a solid substance into the cell is known as __________. phagocytosis pinocytosis pseudopodia photosynthesis

Phagocytosis

Which of the following statements concerning pili is FALSE? A bacterial cell will usually have only one or two pili. Pili facilitate the transfer of DNA among bacterial cells. Pili are longer than fimbriae and flagella. Pili are long, hollow tubules. Not all bacteria have pili.

Pili are longer than fimbriae and flagella

Which of the following would NOT be found in the cytoplasm of a bacterial cell? nucleoid endospores ribosomes porins

Porins

Which of the following statements concerning prokaryotic flagella is TRUE? Prokaryotic flagella are composed of tubulin. Treponema is an example of a bacterium that has a tuft of polar flagella. Prokaryotic flagella move in a whip-like manner. Prokaryotic flagella are anchored to the cell wall by means of the basal body. A "run" results from clockwise movement of the flagellum.

Prokaryotic flagella are anchored to the cell wall by the basal body

The archaea are similar to bacteria in all of the following aspects EXCEPT __________. their cytoskeleton their ribosomal proteins their lack of membranous organelles their mechanism of cell division

Their ribosomal proteins.

What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass? They are completely hydrophobic. They have both hydrophilic and hydrophobic regions. They are completely hydrophilic. They are positively charged.

They have both hydrophilic and hydrophobic regions

Why are ATPases associated with active transport proteins?

They provide transport proteins with the energy needed to pump molecules against their concentration gradients.

What role do the teichoic acids play within the cell wall of Gram-positive bacteria?

They serve to stabilize the cell wall and hold it in place. *Some of the teichoic acids are anchored to lipids within the cytoplasmic membrane and are thus called lipoteichoic acids*

One of the main differences between a Gram-positive and a Gram-negative bacterial cell wall is that the peptidoglycan portion of a Gram-positive cell wall is _____ as compared to a Gram-negative cell wall.

Thicker

Integral proteins are mostly involved in enzymatic function. receptors. recognition sites. transport function.

Transport function

Efflux pumps can be used to pump antibiotics out of a cell once they enter to protect the cell. This will be done against the concentration gradient of the antibiotic. Which of the active transports would most likely be used?

Uniport A uniport would pump the antibiotic out without needing to bring additonal molecules into the cell, and would not allow the antibiotic to diffuse back in

In a hypotonic environment, the vacuole of a plant cell enlarges and pushes the cytoplasm against the cell wall. Which organelles are most likely able to store that extra water? mitochondria vesicles peroxisomes vacuoles

Vacuoles

How is osmosis different from simple diffusion?

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

how are gram-positive and gram-negative flagella different?

a gram-positive flagellum has only two rings in its basal body; gram-negatives each have four

non-specific permeases...

allow a variety of molecules to cross the cytoplasmic membrane.

the rings...

anchor the flagellum to the cell membrane

Which type of active transport protein uses one protein to pump two different molecules?

antiport and symport

What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell? plasma membrane nuclear envelope cytoskeleton endomembrane system extracellular matrix

plasma membrane

Which of the following would not move freely across the cytoplasmic membrane? Small alcohols Dissolved oxygen Dissolved carbon dioxide Positively charged hydrogen ions

positively charged hydrogen ions

Within the peptidoglycan layer, the crossbridges that connect the chains of alternating sugar molecules extend between _____.

two N-acetylmuramic acid molecules The crossbridges link NAM molecules to one another and provide the structural integrity of the peptidoglycan layer