MMB - Ch. 3 Assignment

Within the peptidoglycan layer, the crossbridges that connect the chains of alternating sugar molecules extend between ___. - 2 NAM molecules - 2 NAG molecules - a NAG acid and a NAM acid - 2 glucose molecules

2 NAM molecules (provides structural integrity of the peptidoglycan layer)

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

Gram-positive cell wall

Which of the following statements concerning conjugation pili is FALSE? - Pili are longer than fimbriae and flagella - Pili are long, hollow tubules - Not all bacteria have pili - 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

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

a chain-link fence (the peptidoglycan cell wall is mesh-like, allowing for easy passage of ions, amino acids and nutrients while maintaining structural integrity)

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

amino acids (combine to form the peptide portion of peptidoglycan)

Which of the following is a prokaryote? - protozoa - archaea - algae - fungus - both archaea and protozoa

archaea (and bacteria!)

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

both fimbriae and glycocalyces

Which of the following may be a component of bacterial cell walls? - tubulin - carrageenan - lipoteichoic acids - mycolic acids - both lipoteichoic and mycolic acids

both lipoteichoic and mycolic acids

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

can undergo transcription and translation simultaneously

Some bacteria have an outer layer called a ___ which allows them to adhere to surfaces and contributes to their ability to cause disease. - flagellum - capsule - cell wall - pilus - LPS

capsule

Some bacteria have a water-soluble outer slime layer composed of: - lipid - peptidoglycan - carbohydrate - protein - lipoteichoic acid

carbohydrate

Why is using antimicrobial drugs to kill large numbers of Gram-negative bacteria in a short period of time a cause for medical concern? - dead Gram-negative cells release lipid A, which causes fever and other medical problems - Gram-negative bacteria often contain viruses that are released when they die - dead Gram-negative bacteria are more infectious than live Gram-negative bacteria - dead Gram-negative cells transform into Gram-positive cells, which release exotoxins

dead Gram-negative cells release lipid A, which causes fever and other medical problems

Bacteria of the genus "Mycoplasma" lack cell walls. What sort of environment do they require for survival? - a biofilm - hypotonic - hypertonic - low temperature - isotonic

isotonic

A bacterial cell possesses a glycocalyx (capsule). 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 able to attach to surfaces - it will be less likely to dry out

it will be engulfed more quickly by defensive cells of the host (it does the opposite and allows prokaryotes to pass undetected by defenses)

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

peptidoglycan

The region between the out and inner membranes of a Gram-negative bacterial cell is known as the ___, and is the location of enzymes that assemble peptidoglycan. - cytoplasm - intramembranous space - lipopolysaccharide layer - periplasmic space

periplasmic space (an area surrounding the bacterial cytoplasmic membrane)

Using. microscope, you observe an amoeba moving toward a food source. This is an example of: - reproduction - cellular structure - responsiveness - growth - metabolism

responsiveness

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

sexual reproduction (not all living organisms reproduce sexually)

What types of molecules may NOT need transport proteins to be able to cross cytoplasmic membranes? - small hydrophilic molecules - nothing crosses cytoplasmic membranes without transport molecules - ions - large molecules - small hydrophobic molecules

small hydrophobic molecules

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

tetrapeptides (composed of 4 amino acids and make up the "peptide" portion of peptidoglycan)

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

the cell will gain water

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 and the formation of blood clots. What explanation best describes what happened? - the lysis of the cells releases lipid A form the LPS layer - the antibiotic is toxic and is affecting the patient adversely - the lysis of the cells releases NAG and NAM from the cell wall - any part of the bacterial cell wall released during lysis is seen as foreign and thereby elicits a severe immune response by the body's immune system

the lysis of cells releases lipid A from the lipopolysaccharide layer (lipid A "endotoxin" is known to cause inflammation, fever, and blood clots)

Lipid A is a component of: - the outer membrane of Gram-negative bacteria - Gram-positive bacterial membranes - plant cell walls - bacterial glycocalyces - cytoplasmic membranes

the outer membrane of Gram-negative bacteria

What role do the teichoic acids play within the cell wall of Gram-positive bacteria? They serve: - as adhesins, allow bacteria to bind to one another -as cross-bridges, holding the peptides and sugar molecules together - as pores, allowing the passage of ions, nutrients and amino acids into the cell - to stabilize the cell walls and hold it in place

they serve to stabilize the cell and hold it in place (the teichoic acids anchored to lipids within the cytoplasmic membrane are called "Lipoteichoic Acids"

One of the main differences betweem 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. - positively charged - more lipid rich - composed of a greater percentage of NAGS than NAMS - thicker

thicker (it's much thicker than Gram-negative's layer)