Chapter 4 HW
Indicate the bacterial structures that are likely to be antigens, to which host antibodies bind, marking the invader for phagocytosis:
-capsule -cell wall -fimbriae -flagella Surface components (capsule, cell wall, fimbriae, flagella) are more likely to be "visible" to the host as antigens. Components in the cell's interior (ribosomes, nucleoid, plasmid), are not as likely to serve as useful antigens for the host since they are sequestered within the bacterial cell. Even though they may be antigenic, antibodies against them will not be able to tag the SURFACE of a bacterial cell.
What structures are found in all bacterial cells?
-cytoplasm -plasma membrane -nucleoid -ribosomes (capsules,fimbriae,pili, and cell wall are NOT found in ALL bacteria)
Identify antibacterial strategies that would likely be selectively toxic for bacteria.
-interfering with translation at 70s ribosomes -inhibition of fimbriae synthesis -inhibition of peptidoglycan synthesis Those structures of processes that are unique to bacterial (prokaryotic) cells make excellent targets for antibacterial drugs. These include the peptidoglycan of the bacterial cell wall, the 70s bacterial ribosome, and potentially the bacterial fimbriae. Lysosomes and microtubules are found in eukaryotic cells and would not be appropriate targets for antibacterial drugs.
Which of the following is NOT a classic sign and/or symptom of a urinary tract infection? Painful urination Abdominal discomfort Blood in the urine Increased urgency to urinate
Blood in the urine. *The classic signs and symptoms of a urinary tract infection are: pain due to inflammation of the urethra and bladder, pain or burning during urination, and an urgency to urinate frequently*
The structural framework in a cell is the: cytoskeleton. endoplasmic reticulum (ER). plasma membrane. endomembrane system. extracellular matrix.
Cytoskeleton *The cytoskeleton is the structural framework in a cell ("cyto" refers to cell and "skeleton" refers to a structural framework).*
Which of the following structural features of E. coli is most responsible for the signs and symptoms of a urinary tract infection?
Fimbriae *E. coli uses its fimbriae to attach to surfaces such as to the epithelial cells that line the urethra. This attachment allows E. coli to colonize the surface, inducing inflammation and causing the signs and symptoms of a urinary tract infection.*
Which of the following is part of the endomembrane system? ribosomes cytoskeleton Golgi apparatus flagellum mitochondria
Golgi apparatus *The endomembrane system includes the ER, the Golgi apparatus, lysosomes, and vesicles. It manufactures, processes, and transports lipids and proteins. The Golgi apparatus processes and packages proteins.*
What is the difference between gram-positive and gram-negative cell walls?
Gram-positive and Gram-negative cell walls differ in several key elements. It is the thickness of the peptidoglycan layer that determines the staining reaction. The outer membrane and more specifically the lipoopolysaccharide (LPS) is responsible for some of the toxic properties of gram negative bacteria.
A strain of Streptococcus pneumoniae is no longer able to synthesize its capsular polysaccharide. What is a likely outcome?
It will be readily phagocytized upon entering the host
A strain of Neisseria gonorrhoeae has been genetically altered and can no longer produce fimbriae. What is a likely outcome?
It will be unable to adhere to host tissue and establish infection *Fimbriae are an important virulence factor of Neisseria gonorroheae. These delicate structures support adhesins which enable Neisseria gonorrohoeae strains to adhere to the tissues of a host and establish infection.*
Which of the following organelles breaks down worn-out organelles? smooth endoplasmic reticulum (ER) mitochondria lysosomes rough endoplasmic reticulum (ER) Golgi apparatus
Lysosomes *Lysosomes contain digestive enzymes and break down worn-out organelles.*
Where in a cell is ATP made? ribosomes lysosomes nucleus chloroplasts mitochondria
Mitochondria
Where is the genetic information of the cell stored? nucleus rough endoplasmic reticulum (ER) lysosomes smooth endoplasmic reticulum (ER) Golgi apparatus
Nucleus *DNA is the genetic information of the cell, and it is stored in the nucleus.*
Why are most Gram-negative bacteria resistant to the actions of penicillin?
Penicillin is unable to pass through the outer membrane of the cell wall. *The highly selective outer membrane of the Gram-negative cell wall prevents the uptake of penicillin, rendering it ineffective in the treatment of most Gram-negative infections*
What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell? endomembrane system nuclear envelope cytoskeleton plasma membrane extracellular matrix
Plasma membrane The plasma membrane surrounds the cell and regulates the movement of materials into and out of the cell.
Prokaryotic cells vs. Eurkaryotic cells contain:
Prokaryotic: -70s ribosomes -peptidoglycan-containing cell wall -circular chromosome, not enclosed within a nuclear envelope -flagella that rotate, composed of flagellin Eukaryotic: -80s ribosomes -cellulose or chitin-containing cell wall -linear chromosomes enclosed within a nuclear envelope -flagella that wave, composed of microtubules -lysosomes -mitochondria -golgi apparatus -endoplasmic reticulum
One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by the extracellular matrix. the cytoskeleton. the Golgi apparatus. ribosomes. mitochondria.
Ribosomes *Ribosomes dock on the rough ER, and proteins are completed inside the rough ER.*
Where are lipids made in the cell? rough endoplasmic reticulum (ER) Golgi apparatus mitochondria ribosomes smooth endoplasmic reticulum (ER)
Smooth endoplasmic reticulum(ER)
Which statement best describes how streptomycin attacks bacterial cells?
Streptomycin targets the 70S ribosome and inhibits protein synthesis *Streptomycin prevents protein synthesis by binding to and disabling 70s ribosomes, which are used primarily by prokaryotic cells*
Membrane transport refers to the mechanisms by which solutes cross the plasma membrane, but there are additional prokaryotic cell structures through which a solute would pass when entering or exiting a cell. Sequence the path of a solute from the external environment to the cytoplasm of a prokaryotic cell.
capsule--> cell wall--> plasma membrane
What carries instructions for making proteins from the nucleus into the cytoplasm? ATP Rough ER mRNA ribosomes DNA
mRNA *The "m" in mRNA stands for "messenger"; mRNA is the messenger that carries genetic instructions from the nucleus to the cytoplasm.*