Chapter 3 Flashcards
Movement of a cell toward or away certain chemicals in the environment
Chemotaxis
Bacteria that have a cell wall characterized by a thin layer of peptidoglycan surrounded by an outer membrane, Pink when gram stained
Gram-negative bacteria
Bacteria that have a cell wall with a thick layer of peptidoglycan contain teichoic acid Purple when stained
Gram-positive bacteria
Which molecule makes up the outer layer of the membrane of Gram-negative bacteria
Lipopolysaccharide
Macromolecule that provides strength to the cell wall and only found in bacteria
Peptidoglycan
Gel-like material that fills the region between the cytoplasmic membrane and outer membrane of Gram-negative bacteria
Also, the cytoplasmic membrane and peptidoglycan layer of atleast some Gram-positive bacteria
Periplasm
Cell surface structure that allows cells to adhere to certain materials; some types are involved in a mechanism of DNA transfer.
Pilli
Extra chromosomal DNA molecule that replicates independent of the chromesome.
Plasmid
Layers surrounding the contents of the cell; they include the cytoplasmic membrane, cell wall, amd capsule (if present)
Cell envelope
Which type of cell most often has a capsule. Which rarely do
Bacteria/ archea
Fluid portion of the cytoplasm is called
Cytosol
Region of the prokaryotic cell containing the DNA
Nucleoid
What determines that cells boundary determining what can go into and out of the cell
Cytoplasmic membrane
This describes the dynamic nature of the cytoplasmic membrane
Fluid mosaic model
What can pass through the cytoplasmic membrane freely
Gases, hydrophobic molecules, water
Osmosis occurs when the concentration of salutes on 2 sides of a membrane is unequal
True or False
True
Water flows from hypotonic to hypertonic
True or False
True
Form of energy generated as an electron transport chain moves protons across a membrane to create a chemiosmotic gradient
Proton motive force
Do prokaryotic cells have an electron transport chain?
If so where is it located
Yes
The cytoplasmic membrane
These transporters move waste products and toxic substances out of the cell
Effux pumps
Transport process that moves compounds across a membrane down a concentration gradient, no ATP required
Facilitated diffusion
Energy-consuming process by which cells move molecules across a membrane and against a concentration gradient
Active transport
Type of transport process that chemically alters a molecule during its passage through the cytoplasmic membrane
Exp.
A phosphate group is added to a sugar- a modification called Phosphorylation
Group translocation
Facilitated transport is commonly used in prokaryotic cells
True or False
False
Active transport
In prokaryotic cells which type of energy is used?
Proton motive force & ATP
In this type of transport mechanism the molecule is chemically altered
Group translocation
How do macromolecules get into prokaryotic cells?
They are first broken down by exoenzymes.
Active transport
Amino acid sequence that directs cellular machinery to secrete a polypeptide
Signal sequence
What serves as the backbone to peptidoglycan?
NAM & NAG
N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)
Attached to the NAM molecule is a _______ (a string of 4 amino acids) that play an important role in the strength of peptidoglycan
Tetrapeptide
In ______ the connection between tetrapeptide chains is direct, whereas in _________ the connection is usually via a peptide interbridge
Gram-negative/ Gram-positive
A cell wall glycopolymer found in gram-positive bacteria.
Teichoic acid
Peptidoglycan is a polymeric macromolecule made up of linear glycan strands attached to each other by ___________
Peptide bridges
In prokaryotic cells, the unique lipid bi-layer of Gram-negative cells that surrounds the peptidoglycan layer
Outer membrane
The outer layer of Gram-negative is made of ….
Lipopolysaccharide LPS
LPS component of the outer membrane of Gram-negative bacteria, lipid A is responsible for the toxic properties of LPS and is called an…
Endotoxin
2 notable parts of the lipopolysaccharide
Describe
Lipid A: anchors the LPS in the lipid bilayer. This is the portion the body recognizes as invading Gram-negative bacteria
O antigen directed away from the membrane these sugar molecule chains are used to identify species or stains
Like the cytoplasmic membrane the _______ serves as a barrier to the passage of most molecules
Outer membrane
Proteins in the outer membrane of Gram-negative bacteria that form channels through which small molecules can pass
Porins
Gram-negative are (more or less) sensitive to medications than gram-positive?
Why
Less
They includes the outer membrane
These play a critical role in the disease process of certain pathogens by allowing proteins across both the outer membrane and cytoplasmic membrane
Secretion systems
Región between the cytoplasmic and outer membrane is called….
In gram-negative bacteria all exported proteins accumulate here unless specifically moved across the outer membrane as well
Periplasm
This interferes with peptidoglycan synthesis by preventing cross-linking by inhibiting the enzymes that make crosslinking possible
Penicillin
This enzyme breaks the bonds that link alternating subunits of glycan chains.
It has trouble getting past the outter membrane on gram-negative so it is more effective on gram-positive bacteria
Lysozyme
Mycoplasma is special because….
It lacks a cell wall
What is a type of bacteria that neither penicillin nor lysozyme can affect?
Mycoplasma
Archea have this located in the cell wall which are subunits that self-assemble
S-layers (sheets of flat proteins or glycoproteins)
Which type of bacteria has teixhoic acids?
Gram-positive
A distinct, thick gelatinous material that surrounds some microorganisms
Capsule
A diffuse and irregular material that surrounds some microorganisms
Slime layer
Function of the Capsule/ Slime layer
Interferes with the immune system
Protección or to attach to a surface
Capsules and slime layers are commonly referred to as…
Glycocalyx
Polymer-encased community of microorganisms is called
Biofilm
The polymers of biofilm are collectively known as …
Extracellular polymeric substance EPS
What are peritrichous flagella?
Flagella located all around the cell
A single flagella located at 1 end of the cell is called
Polar flagella
3 parts of flagella Start with the one closest to the cell body
Basal body: attaches the structure to the cell wall and cytoplasmic membrane
Hook: flexible curved segment that extends from basal body, connecting it to the filament.
Filament: the part that spins to create motion
The filament of the flagella is made from subunits called…
Flagellin
How do flagella get the energy to propell themselves
Proton motive force
Archaea don’t have flagella they have _____ for locomoción
What are the differences between flagella and Archeas Locomotion systems?
Archaella
Archella use ATP instead of Proton motive force.
They are not hollow and about half the size.
Common pili or ______ allow bacterial cells to attach to specific surfaces
Fimbriae
Pili can be used for sex
True or false
True
Describe the appearance of the prokaryotic chromesome
Single, circular double stranded DNA molecule
Region of the prokaryotic cell that contains DNA
Nucleoid
Extrachromosomal DNA molecule that replicates independent of the chromesome
Plasmid
What accounts for the increasing frequency of antibiotic-resistanant bacteria?
Plasmid transfer between bacteria
What are the ribosomes called in Prokaryotic cells?
Eukaryotic cells?
S70
S80
Bacteria have proteins that are similar to the cytoskeleton, what is the function of the cytoskeleton?
Provide support and structure to the cell
An accumulation of a high-molecular-weight polymer synthesized form a nutrient that a cell has in relative excess.
Storage granule
These small rigid structures physically seperate certain reactions or functions from the cells cytosol.
Give the 3 examples and their functions
Protien based compartments
Gas vesicles: boyence
Bacterial microcompartments: Contain enzymes
Encapsulin nanocompartments: Hold certain proteins in protection, Example is binding of IRON
What causes endospore formulation or sporulation?
Limiting amounts of Carbon or Nitrogen
Layers outside the cell wall, usually made of polysaccharides, often involved in biofilm formation
Capsules and slime layers
This type of bacteria contains teichoic and lipoteichoic acids
Gram-positive
Thin peptidoglycan, surrounded by outer membrane, outer membrane made if lipopolysaccharide
Gram-negative
Lumen is the interior of an organelle
True or False
True
A molecule that specifically binds to a given receptor is called…
Ligand
Interaction between what is important in cell signaling?
Receptor - ligand
What provides strength to Eukaryotic membranes
Sterols
What is ergosterol?
The sterol in the Fungus membrane that makes it stronger.
______ is a type of protein found in the cell membranes that transports certain compounds across the membrane. May also be called permease or transporter protein
Carrier
Cells of multicellular organisms often take in nutrients by facilitated diffusion
True or False
True
Cells use _____ to take in material too large to fit through transport proteins.
Endocytosis
Pinocytosis is a type of endocytosis where the cell…
Drinks
This is used by cells to take up extracellular ligands that bind to the receptors surface
Receptor-Mediated endocytosis
Secretary vesicles inside the cell fuse with the cytoplasmic membrane and release their contents out of the cell
Exocytosis
These proteins allow the cell cytoplasm to move
Actin Filaments
The thickest of the cytoskeleton components is responsible for forming the mitotic spindles, are made of tubulin, and main structures that make up cillia and flagella
Microtubules
This part of the cytoskeleton strength the cell mechanically and allows the cell to resist physical stress.
Intermediate filaments
What is the boundary of the nucleus
Nuclear envelope
What allows large molecules such as ribosomal subunits into and out of the nucleus
Nuclear pores
The nuclear envelope is a phospholipid bilayer
True or False
True
It is a double phospholipid bi layer
Mitochondria has 2 membranes the outer is smooth but the inner is highly folded forming invaginations called….
Cristae
Purpose of the cristae in mitochondria
Increase surface area to increase ATP production
Gel like material of mitochondria that contains DNA, Ribosomes and other molecules necessary for protein synthesis
Matrix
Theory that the ancestors of mitochondria and chloroplasts were bacteria that had been residing with in other cells in a mutually beneficial partnership
Endosymbiotic theory
Which 2 organells are throught to be former bacteria that is now in a symbotic relationship with Eukaryotic cells?
Mitochondria & Chlorophyll
They both have their own DNA & Double membrane cells
The flagella of this type of cell have a 9 + 2 arrangement of Microtubules
Eukaryotes
Where are proteins not designed for the cytoplasm made?
Rough ER
Smooth ER does not only lipid synthesis but…
Calcium ion storage
In microscopy, the number of different visible shades in a specimen
Contrast
Microscope that give a 3D appearance
Differential interference contrast DIC
These microscopes project a Lightwave “into” a specimen rather than through
This allows the observer to view microbes attached to opaque substances such as dirt
Fluorscene microscope
Type of microscope that scans laser beams across a specimen, allowing 3D images of a thick structure to be constructed
Scanning laser microscope
Type of scanning probe microscope that has a tip mounted so it can respond to the slightest force between the tip and the sample
Atomic force microscope
Increases contrast by amplifying differences in refractive index
Phase-contrast microscope
2 light beams pass through the sample and recombne for a 3D image
Differential interface contrast
Mirrors scan a laser beam across successive regions and planes of a specimen. From that a computer constructs a 3D image
Scanning laser
Difference between Transmission & Scanning Electron Microscope
Transmission electrons go through sample
Scanning goes back and forth over the surface of a specimen
4 steps in the gram staining technique
- Primary Stain: Crystal violet in this case.
- Rinse, add Gram’s iodine
- Rinse, add 95% Alcohol
- Rinse, 2ndry stain “counter stain” used to dye the Gram-negative. Red safranin is used for this purpose.
A procedure used to stain microbes that don’t take up dyes, Mycobacterium
Acid-fast stain
Acid-fast staining
3 steps
- Red dye Carbol Fuchsin
- Rinse, Acid Alcohol Decoloring agent
- Methy Blue is the counter stain
India ink is added to a suspension of cells to make a wet mount. Only the background is dyed allowing the capsule to be seen
What type of stain is this
Capsule stain
Malachite green is the typical dye used. Gently heated and rinsed with water. Countered stained with safranin red is done to observe these
Endospores
Organic compound is…
Oxygen, Hydrogen, Carbon
What keeps proteins from unwinding
Sulfrhyl Group
Cellulose is aka and is indigestible
Fiber
A bacterial polysaccharide is called…
Dextran
Nucleotides are linked by ________ phosphate groups
Covalent
Which are double rings in the nucleotides.
Single rings
Double rings AG Purine
Single Ring Pyridamine
methylene blue, crystal violet, malachite green, and safranin are this kind of dye
cationic or positively charged dyes bind to negatively charged components in the cell membrane and cytoplasm
Basic dyes
Which dyes are cationic or positively charged.
Which dyes are anonic or negatively charged
Catonic = basic
Anonic = Acid
What is the charge of the bacterial cell membrane
Negative
Acid dyes included
India ink, Congo red, nigrosoine
Which is more negatively charged
Gram Positive or Gram Negative
Gram-positive
Which type of cells always has tightly coiled chromesomes
Prokaryotic
Use _____ to intensify the contrast between the object and the background
Stain
What part of the microscope control the brightness of the light bulb
Rheostat
These are damage caused to the specimen during preparation and can be seen on the microscope slide
Artifacts
What increases the binding of a stain
Mordant
Pleomorphic means ….
Many shapes
This cork-screw shapped bacteria is more rigid
While this type moves with an expanding & twrilling motion
Spirillum / Spirochete
Mrna –> _____, —> Trna
Rrna
What are the anti-codons for
DNA A G C
–|–|–|–
RNA
U C G
What transfers in the Pilli?
Plasmids
Gas vesicles are common in this type of bacteria
Aquatic bacteria
What is special about the archea phospholipid layer
It’s only 1 layer and the tails are not fatty acid
Diffusion of solid or gas through a membrane is called
Dialysis
What will happen to a bacteria in a hypotonic solution?
Hypertonic?
Hypotonic water will enter until a safe point due to the cell wall
Hypertonic the water will leave the cell shriveling it
An effux pump is responsible to this type of movement in and out of the cell by using Proton Motive Force
Active Transport
Polypeptides tagged for secretion via _________ of amino acids
Signal sequence
Why is gram positive more negatively charged?
Teichoic acid makes it more negatively charged
How does penicillin work
Prevents dividing bacteria from forming a cell wall
Where will you find lysozyme
Tears, saliva, bodily fluids
Which type of alcohol for gram stain?
Which type for acid fast stain?
Aceton for Gram
Acid alcohol for fast acid
Mycobacterium is used in which kind of staining? Does it have a cell wall
Mycoplasma does it have a cell wall?
Mycobacterium is used in Acid Fast staining and it does have a cell wall
Mycoplasma does not have a cell wall.
Pilli for attachment =
Fimbriae
The cell wall gives plant cells their shape what give animal cells their shape?
Cytoskeleton
This carries the sequence of Codons while this carries the Anticodons
mRNA CODONS
tRNA AntiCodons
____________ allow the microorganisms to regulate their internal environment by removing toxic substances, including antimicrobial agents, metabolites and quorum sensing signal molecules.
Efflux pumps
