Chapter 3 Flashcards
B) How much does an electron microscope magnify?
100,000 x
Look over table 3.1
pg40
D) How does a bright-field microscope work?
light passes through a specimen then through a sereis of lenses
E) What is the defining characteristic(s) of a compound microscope?
multiple lenses
1) What does a condenser lens do?
F) What is resolving power and what affects it? [Figure 3.2]
1- condenser lense- focuses light on specimin
Resolving power- how close two things can be to see then clearly. light/ na of condenser+na of objective
G) What is the refractive index? [Figure 3.3]
How light is bent or travels through that stuff. Why we use emersion oil
H) What is contrast?
is difference when looking at it.in comparison to others, that is why we stain
J) How does a dark-field microscope work? [Figure 3.4]
dark field stop on end of condenser lense. works like light shining into dark room helps you see dust. cells viewed as bright objects on dark background
H) How does a phase-contrast microscope work? [Figure 3.5]
makes denser material apear darker… does this by amplifying the differences of refractive index of different parts of a cell due to it’s density. uses special optial devices to do this
How does a differential interference contrast microscope work? [Figure 3.6]
provides a 3d image. device seperates light into two beams that pass through a specimen and then recombine
J) How does a fluorescence microscope work and, what is it used for? [Figure 3.7]
used to see cells that are naturally florescent. light doesn’t need to pass through the cells instead project a uv light onto the cells.
K) How does a scanning laser microscope work? [Figure 3.7]
detailed interior view of intact cells. use a florecent stain or tag
L) How does a confocal microscope work?
use a laser beam to illuminate a specific point on a vertivle plane of the specimin and uses mirrors to scan then a computer constructs a 3D image
M) How does a multiphoton microscope work?
uses a lower energy light than the confocal microscope so you can get images of live cells
N) How do electron microscopes differ from light microscopes?
use instead of light wave, uses electron waves. must be in a vacume or the air interferes with the electron waves.
How does a transmission electron microscope work?
used to observed fine detail of cell structure. uses electrons to pass through cell.. the darker segments are denser and electrons do not pass through it. use thin sectioning , or freese fracturing. where you slice the cell to see the inside
How does a cryo-electron microscopy work?
freeze the specimen and then they take different angles to form a 3d image
Q) How does a scanning electron microscope work? [Figure3.11
surface details of a cell. coats the cells with the thin metal film and then electrons are released from the coated cells and the microscope picks up the raditation
How does an atomic force microscope work?
compared to a stylus arm on record player that senses all the bumps on the exterior
A) What is the first step when staining bacteria? [Figure 3.13]
spread specimin on slide
B) What is the defining characteristic of a simple stain?
single dye is used
C) What does a negative stain look like and how is it done?
dye that stains the background…. cell repels the neg charged stain
D) What is a differential stain used for? What are the two most frequently used?
distinguish one group of cells from the other. Gram and acid fast stains
1) How is a gram stain done? [Figure 3.14 and gram stain video]
q
-What is the difference between a gram negative and a gram positive bacterium.
Gram pos- has the thick peptoglycogen membrane over the phospholipid
Gram neg- is 2 lipid layers with small peptogycogen in betweeen
2) What is an acid fast stain used for and how is it done?
detect myobacterium which do not easily take up dies.
put red dye which is really powerful, or you heat it to melt the waxy . Then you apply the acid alchohol….the cells that retain the dye are acid fast cells. and then you add a blue dye as a countersain
E) What does a capsule stain let you see? [Figure 3.16]
use a negative stain and the capsules (gel like outer layer, do not absorb the dye.
F) What does an endospore stain let you see? How does it work? [Figure 3.17]
Dye with a malachite green and heat. Then rinse and add a counterstain to see the rest of the cell( baccilus and clostridium)
G) How can you visualize flagella? [Figure 3.18]
add a flagella stain that coats the flagella making it thicker and more visible
H) When is fluorescence used? [Figure 3.19]
q
1) What is immunofluorescence?
uses an antibody to tag specific protiens with a florescent dye
A) What shapes do bacteria come in and what are their names? [Figure 3.21]
-cocus = round
-rod /baccilus
-vibrio- like a macaroni noodle
-spirillium-
spriochete- like spirillium, but tighter
B) What are the names for typical cell groupings? [Figure 3.22]
Chains, packets and groupings
C) What are multicellular associations?
bacteria live/ work together. ie. group releases a slime that helps break down other organisms
D) What are the structures of the prokaryotic cell? [Figure 3.23]
- Cell envelope
Capsule
Cell wall
Cytoplasmic membrane
-cytoplasm
- nucleiodA) What is the cytoplasmic membrane? How is it’s structured? [Figure 3.24]
thin structure that defines the boundery of the cell and surrounds the cytoplasm.
composed of phospholipids and protiens
B) What is the fluid mosaic model?
refers to the fact that the membrane protiens move around in the phospholipid bilayer
C) What does being selectively permeable mean? [Figure 3.25]
It only allows certain things to pass through the membrane. usually only allowing sm gases, water, and hydrophobic molecules
D) What are aquaporins?
“water gates” that let in water to the cell
electron transport chain
in membrane takes the electons off hydrogens and pumps the hydrogen(protons) out of the cell creating a gradeint.. then cell allows them to come back in and the energy makes atp
A) What mechanism allows things to enter the cell? [Figure 3.28 and Table 3.4]
transport protiens
B) What is facilitated diffusion and how does it work? [Figure 3.29a and How Facilitated Diffusion Works video]
uses transport protien to move something down it’s concentration gradient
C) What is active transport and what are the mechanisms? [Figure 3.29b]
Moves compounds against the concentration gradient.
2 mechanisms
-atp-ABC transport system uses atp these use specific binding protiens on outside of cell to gather and deliver molecules
-proton motive force-uses the movement of the protons to propel pumps to pump things out or come in with the flood of the protons
D) What is group translocation and how is it done? [Figure 3.9c and Active transport by group translocation video]
transport process that as it bring it through the membrane chemically alters it- usually phosphorylating
E) What is the process of secretion? [Figure 3.30]
signal sequence causes cell to secrete it…. during which it takes off teh sequence and the protien will fold into it’s functional shape
1) How does a cell know which polypeptides to secrete?
the aa signal sequence
1) What is peptidoglycan? What is its basic structure and where is it found? [Figure 3.31 and Peptidoglycan Biosynthesis video]
Found in cell walls. It is an alternating of two major subunits NAM n acetylmuramic
(Composed of tetrapeptide chains and link to adjacent glycan chains), and NAG n acetylglucosamine
What are teichoic acids and where are they found? [Figure 3.32]
neg charged chains in gram pos cell walls that stick above the pept. layer and bind to cations. ribitol or glycerol phosphate that attatch to various sugars
3) What kind of bacterium have lipopolysaccharides on it’s outer membrane? [Figure 3.33]
-
Gram neg cell wall outermost lipid layer. lps signals humans defense systems (endotoxin)
-What are the two parts of the LPS molecule?
Lipid a- links to the other bilipid layer
Oantigen chain of sugar molecules on outermost part
4) What are the functions of porins?
Specialized channels that allow many different molecules to pass
B) What is periplasm and where is it found?
gel like substance in the periplasmic space betwwn cytoplamic membrane and outer membrane
C) How does Penicillin work and what is it most effective against?
Penicillin: interferes with peptogylcan synthesis- better affects gram positive bacteria
D) What is Lysozyme and what does it do?
breaks down molecules. is used in the lab to break down peptoglycan layer
E) What is the reason behind why cells are either pink or purple after a gram stain?
purple -gram positive
F) What type of bacteria lack a cell wall? [Figure 3.34]
Mycoplasma cytoplasmic membranes have sterols in it.
G) What type of cell walls do Archaea have?
do not have peptoglycogen. they have pseudo pepto. and have slayer which are sheets of proteins
What is the difference between a capsule and a slime layer? [Figure 3.35]
1) What are they both composed of? 2) What function do they serve?
Capsule:distinct and gelatinous layer around cell wall
Slime Layer: irregular gelatinous lauer
mainly composed of polysacharides like glycocalyx
act as adhesion so the cell can stick to other things
avoid host defense systems (phagocytosis)
1) What are the flagella’s three basic parts? [Figure 3.37]
philament, hook, and basal body
2) What type of flagella arrangements are there?
petrichous- all around
polar- 1 flagella at one end of cell
B) What is the phenomenon known as chemotaxis? [Figure 3.38, 3.39 and Chemotaxis—ecol/ video]
bacteria sense a chemical and respond by moving in a certain direction.
C) What are pili and what function do they have? [Figure 3.40]
allow cells to atatch to certain surfaces, and movement
1) What are fimbriae and what do they do?
pilli that attatch to cells
2) What type of pilus is used for DNA transfer?
sex pilus
) What are plasmids?
circular supercoiled dna. smaller than the chromosome.
some code for production of enzymes that resist antibiotics
C) What are ribosomes? What are the different types? [Figure 3.42]
involved in protien synthesis
Prokaryotic 70S
and
Eukaryotic 80s
What are storage granules and what is their use? [Figure 3.43]
accumulation of polymers that cell will use later and so they store it in prep of replication
E) What are gas vesicles and what is their function?
protien bound compartments that provide bouyance to the cell
F) What are endospores? What is special about them? [Figure 3.44 and Bacterial Spore Formation]
?
Endospores released by cells that lack nutrients. Dormant cells produced by baccilus and clostridium. They are almost indestructable!
1) When and how do they germinate?
?
2) What is a vegetative cell?
one that multiplies
3) What is the process of sporulation
cell senses starvation
dna is duplicated
and septum forms
larger compartment engulfs smaller forming a forespore in mother cell
Ppeptoglycan is laid around the forespore
mother cell is degraded and releases the endospore
A) What is a plasma membrane, what function does it serve, and who has one?
Eukaryotic cells!
Typically a phospholipid bilayer
C) What are the active and passive transport mechanisms of the eukaryotic cell?
q
D) What is endocytosis and exocytosis? How is it done? [Figure 3.48]
endo- brings in. membrane invaginates then seals off
exo- kick out,
E) How is secretion done in the eukaryotic cell?
same as eukaryotic
) What type of ribosome does the eukaryotic cell have?
80s
B) What is the cytoskeleton? What is it made of? [Figure 3.49]
Cytoskeleton frame work of a cell
made of actin filaments, microtubules and intermediate filaments
C) What are flagella and cilia made of and how do they differ? [Figure 3.50]
made of microtubules!
A) What is the nucleus? What is it composed of? What events take place there? [Figure 3.51]
Composed of nuclear envelope
- 2 lipid bilayers (inner and outer membranes)
- in the membranes are protiens that create pores
DNA wound in histones is there
Nuleos is where the rna is manufactured and is linear (opposite of inside prokaryotes)
B) What is the function of mitochondria? What is it composed of? [Figure 3.52]
power house
2 lipid bilayers:
1 round and the other folded
contains dna ribosomes and other molecules
1) What is endosymbiotic theory?
That eukaryotes evolved from prokayotes: founded based that the mitochandira divide in a similair fashion to prokaryotic cells.
lysosomes? What process are they involved in?
autophagy ( digestion of uneeded cell components)
G) What are peroxisomes?
detox the cell using o2 and help break down lipids
C) What is the function of chloroplasts and where are they found? What are they made up of? [Figure 3.53]
in plants and algea. harvest sunlight to produce e
