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Block 1 Heywood 1-4
forGrayson
137
Microbiology
Graduate
08/28/2010

Additional Microbiology Flashcards

 


 

Cards

Term
(4) LM methods
Definition
bright-field, phase-contrast, Nomarski differential-interference contrast, dark-field microscopy
Term
(5) TEM specimens must be stained using...
Definition
heavy metal atoms, such as osmium, lead, uranium, tungsten and gold
Term
osmium tetroxide
Definition
binds to double bonds between carbon atoms in lipids
Term
uranyl acetate
Definition
binds to nucleic acids, so stains nucleoli, ribosomes, and chromatin
Term
%protein vs. lipid in... myelin?
Definition
80% lipid, 20% protein by weight
Term
%protein vs. lipid in... inner mitochondrial membrane?
Definition
75% protein, 25% lipid by weight
Term
(2) Peripheral proteins normally regulate...
Definition
ion channels and cell signaling
Term
(3) Integral proteins normally function as...
Definition
membrane receptors and transport proteins, and to attach cells to each other/extracellular matrix
Term
Rhodopsin
Definition
a protein with several transmembrane proteins arranged to form a pore across the cell membrane
Term
(2) oligosaccharides are important in...
Definition
cell-cell recognition, e.g. immunology and embryonic development
Term
Epidermolysis bullosa simplex
Definition
mutation in keratin genes, resulting in epidermal cells easily fracturing and causing blistering. (damages desmosomes)
Term
Focal adhesions and hemidesmosomes link to the extracellular matrix via...
Definition
integrins
Term
Focal adhesions / hemidesmosomes anchor to...
Definition
actin / intermediate filaments
Term
(2) What closes / opens connexons?
Definition
Closes - high pH or low Ca2+, opens - low pH or high Ca2+
Term
(3) SER is plentiful in...
Definition
1) cells producing cholesterol -> steroid hormones, 2) cells that detoxify drugs, and 3) in muscle cells, where calcium is sequestered in the sarcoplasmic reticulum causing relaxation of myofibrils and vice versa
Term
(3) Free polyribosomes translate proteins of the...
Definition
cytosol, nuclei, and mitochondria
Term
(5) RER ribosomes translate proteins of...
Definition
plasma membrane, Golgi, lysosomes, ER, cell exterior
Term
What can be made by both RER and free ribosomes?
Definition
peroxisomes
Term
(3) Posttranslational entry
Definition
entry of proteins translated on cytosolic ribosomes into mitochondria, perosixomes and nuclei
Term
ER cisterna
Definition
protein folding site; oligosaccharides added
Term
Stop-transfer signal
Definition
alpha helix which ensures that transmembrane segments of translated proteins in ER are correctly positioned within the ER membrane
Term
COP-II coated vesicles
Definition
hold proteins and lipids; exit the ER and enter the cis-Golgi
Term
COP-I coated vesicles
Definition
transport material from cis to trans
Term
SNARE proteins
Definition
catalyze the fusion of vesicles to the appropriate membranes
Term
t-SNARES
Definition
attached to target membrane
Term
v-SNAREs
Definition
attached to vesicles
Term
Rab proteins
Definition
GTPases that aid SNAREs
Term
ER resident proteins
Definition
function in the ER cisterna, but often are packaged in vesicles because they are soluble. A rentention signal allows them to attach to receptors in the Golgi cisterna to be returned via retrograde COP-I vesicles, which also return membrane to the ER.
Term
What directs proteins to their appropriate vesicles?
Definition
Sorting signals
Term
(3) exocytosis pathways
Definition
signal-mediated diversion to secretory vesicles, signal-mediated diversion to lysosomes, secretion via the constitutive secretory pathway
Term
Regulated secretory pathway
Definition
Golgi products (such as insulin in the beta cells of the pancreas) are stored in secretory vesicles which are released rapidly in response to hormonal or neural stimuli
Term
constitutive secretory pathway
Definition
Golgi products are immediately discharged at the cell surface for production of the extra cellular matrix
Term
extracellular matrix
Definition
a gel of glycosaminoglycans and proteoglycans in which fibrous proteins are embedded
Term
(4) embedded fibrous proteins in the ECM
Definition
fibronectin, laminin, collagen, elastin
Term
fibronectin
Definition
attaches fibroblasts to the ECM
Term
laminin
Definition
to attach epithelium to basal lamina
Term
Leishmania
Definition
a parasite which prevents vacuoles from fusing with lysosomes; uses phagocytosis to enter cells.
Term
(2) what causes the clathrin pit to pinch off as a coated vesicle in receptor-mediated endocytosis?
Definition
Dynamin and GTP
Term
End product of receptor-mediated endocytosis
Definition
endosome
Term
lysosome
Definition
contains proteases, lipases, phosphatases with optimal activity at ph=5, maintained by ATP-driven proton pumps
Term
what protects lysosomal enzymes against autolytic protease digestion?
Definition
glycosylation
Term
How do lysosomes digest things?
Definition
Molecules via receptor-mediated endocytosis, cells and cell fragments via phagocytosis, old cell components from their own cells via autophagy. Lysosomal enzymes break down their substrates into amino acids, sugars and nucleotides which then enter the cytosol via transport proteins in the lysosomal membrane.
Term
What is a lysosome's defining enzyme?
Definition
Phosphatase
Term
What happens to lysosomal enzymes when golgi vesicles containing them fuse with the plasma membrane
Definition
Term
What happens when golgi vesicles containing lysosomal enzymes fuse with the plasma membrane and release their contents?
Definition
Lysosomal enzymes attach to the M6P receptor and re-enter the cell when it is endocytosed.
Term
I-cell disease
Definition
Deficiency of enzyme which phosphorylates mannose = no targeting of enzymes to lysosomes. Substrates (mucolipids and mucopolysaccharides) build up in cytosol causing coarse facial features, mental retardation and skeletal abnormalities.
Term
Tay-Sachs disease
Definition
absence of lysosomal enzyme Hexoaminidase A results in build-up of gangliosides in the brain -> mental retardation, blindness, and death by early childhood in the infantile version of the disease
Term
(4) Peroxisomes
Definition
Single membrane surrounding a granular matrix. Creates hydrogen peroxide, breaks down hydrogen peroxide, inactivates toxic molecules by oxidizing them using hydrogen peroxide, break down fatty acids. Abundant in liver.
Term
Zellweger's Syndrome
Definition
Build-up of toxins in cytosol results from poor coduction of enzymes to peroxisomes. Hepatomegaly and high levels of iron and copper in the blood stream result, often fatal in infancy.
Term
Neonatal adrenoleukodystrophy
Definition
Very long chain fatty acids cannot be broken down in peroxisomes, resulting in a build-up in the brain. This destroys myelin sheaths and causes a deficiency of adrenal steroid hormones in the adrenal glands. = Lack of the degradative proteins needed for beta-oxidation to occur.
Term
catalase
Definition
enzyme by which peroxisomes break down hydrogen peroxide
Term
cristae
Definition
invaginations of the IMM
Term
IMM contains...
Definition
ATP synthases which extend into the matrix
Term
(5) mitochondrial matrix contains...
Definition
enzymes for Krebs cycle and for oxidation of fatty acids and pyruvate. Also ribosomes, tRNAs and mitochondrial DNA.
Term
mitochondrial site where protons accumulate
Definition
intermembrane space
Term
Glycolysis occurs in the
Definition
cytosol
Term
Glycolysis yields
Definition
glucose -> 2 pyruvate + 2ATP + 2NADH
Term
2 pyruvate -> 2 acetyl-CoA occurs where and yields what
Definition
mitochondrial matrix, 2CO2 and 2 NADH
Term
cytochrome c oxidase
Definition
site in electron-transport respiratory chain at which O2 and water are formed
Term
oxidative phosphorylation
Definition
phosphorylation of ADP to ATP driven by the flow of protons across the IMM
Term
TCA cycle yields
Definition
4CO2, 2GTP, 6 NADH (and 2FADH2 after 2 turns)
Term
total mitochondrial yield
Definition
30-38 molecules of energy (ATP and GTP) per glucose molecule
Term
hsp70 chaperone protein
Definition
prevents mitochondrial proteins (which are coded by nuclear genes and translated on cytosolic polyribosomes) from folding, and is necessary for the import of these proteins into the mitochondria.
Term
(4) Import of mitochondrial proteins requires
Definition
signal sequence, hsp70 chaperone protein, proton gradient across IMM and ATP.
Term
Mitochondrial DNA
Definition
mtDNA, maternal inheritance in humans, lacks histones. circular double helix in humans.
Term
cycloheximide
Definition
eukaryotic protein synthesis is sensitive to this, but prokaryotic and mitochondrial is not.
Term
chloramphenicol
Definition
eukaryotic protein synthesis is insensitive to this, but mitochondrial and prokaryotic is sensitive.
Term
mitochondrial ribosomes
Definition
are smaller than cytosolic ribosomes, affecting antibiotic efficacy.
Term
Heteroplasmy
Definition
caused by mutations in mtDNA - some fine, some damaged. cell damage or death results if too many are damaged.
Term
Leber's Hereditary Optic Neuropathy
Definition
CGU->CAU = arginine->histidine in NADH dehydrogenase, inactivating the enzyme. ATP formation is blocked in many mitochondria of optic nerve cells, causing them to die -> blindness (maternally inherited)
Term
microtubules in the cilia are stable or dynamic?
Definition
stable (long-lived)
Term
alpha is +/-? beta is +/-?
Definition
alpha = -, beta = +
Term
vinblastine and vincristine
Definition
drugs which depolymerize microtubules
Term
What is F-actin formed from?
Definition
G-actin monomers
Term
ARP complex
Definition
site of de novo synthesis of F-actin. contains two Actin Related Proteins. Pre-existing F-actin is polymerized during normal movements of cells like fibroblasts.
Term
Listeria
Definition
a bacteria which polymerizes actin to get to a host's cytoplasm and cause food poisoning.
Term
2 structures with actin inside
Definition
stereocilia, microvilli
Term
(3) actin-binding proteins
Definition
fimbrin (bundles them together), filamin (cross-links them), gelsolin (fragments them)
Term
myosin moves toward which end of actin microfilaments?
Definition
+ end
Term
Nuclear lamins
Definition
intermediate filaments which occur in the nucleus. lamins A, B, and C are phosphorylated in late G2, causing breakdown of the nuclear lamina.
Term
motor molecules associated with microtubules
Definition
kinesin, dynein
Term
another word for centriole
Definition
basal body
Term
what kind of enzyme is dynein?
Definition
ATPase
Term
what connects subdoublets in cilia?
Definition
nexin
Term
bacterial flagella
Definition
a group of protein filaments the end in a circular motor, the rotor. an intermembrane proton pump fuels the rotor, pushing protons past the filaments to rotate them.
Term
(3) each chromosome consists of specialized DNA for
Definition
the centromere, the telomeres, and the replication origins of DNA.
Term
nuclear lamina
Definition
fibrous layer (intermediate filaments) inside the inner nuclear membrane. disperses when lamins are phosphorylated in late G2 and early prophase; reappears in telophase
Term
nuclear pores are made up of proteins called
Definition
nucleoporins
Term
nuclear transport protein complex
Definition
binds to proteins over 40,000 daltons that need to cross into the nucleus and transports them. a similar process drives export of ribosomal subunits, tRNA and mRNA back into the cytoplasm.
Term
nucleopores have a high/low rate of bidirectional transport
Definition
high
Term
nucleolar organizing regions
Definition
10 groups of rRNA genes which are are located on both homologs of 5 chromosomes (200 total)
Term
which rna polymerase makes pre-rRNA subunits?
Definition
rna polymerase 1
Term
ribosomes are formed in the nucleolus or the cytosol?
Definition
cytosol - the subunits are made in the nucleolus, but they don't come together until the start of translation in the cytosol
Term
phases of the cell cycle
Definition
G1, S, G2, M
Term
G0
Definition
lengthy G1-type phase for cells that are not actively dividing
Term
In late G2, a __________________ causes widespread phosphorylation
Definition
cyclin-dependent kinase
Term
phosphorylation of _________ causes chromosome condensation and this does what?
Definition
histones; stops transcription
Term
what drives polymerization of MTs to form the mitotic spindle?
Definition
phosphorylation
Term
3 types of spindle MTs
Definition
aster MTs, overlapping MTs, kinetochore MTs
Term
when is a chromatid a chromosome?
Definition
when the chromatids separate at the metaphase/anaphase transition
Term
anaphase a
Definition
kinetochore MTs depolymerize, pulling the chromatids apart
Term
anaphase b
Definition
sliding occurs between overlapping MTs, pushing apart the poles. astral MTs contribute at the cell periphery (the minus end)
Term
during telophase, the nucleolus is formed from
Definition
10 small nucleoli at the sites of rRNA genes
Term
what forms a contractile ring during cytokinesis?
Definition
actin and myosin II
Term
necrosis features
Definition
an inflammatory response
Term
(2) apoptosis features
Definition
endonucleases and macrophages
Term
(4) similarities between prokaryotes and eukaryotes
Definition
membrane structure, DNA structure, the genetic code and some metabolic pathways
Term
(5) differences between prokaryotes and eukaryotes
Definition
p's are smaller and unicellular. they have no organelles or cytoskeletal components. p's have a nucleiod.
Term
nucleoid
Definition
region of DNA in prokaryotes that has no nuclear envelope or organization
Term
(6) how are specimens prepared for TEM and LM?
Definition
fixed in buffered, isotonic fixative like glutaraldehyde. washed in buffer, dehydrated in ethanol, embedded in plastic
Term
thymidine stain
Definition
used for nuclear DNA only
Term
sodium and glucose symports occur where?
Definition
only the apical surface of intestinal endothelium. glucose passes by passive transport at the basolateral surfaces.
Term
catenin
Definition
links cadherins to actin filaments
Term
what removes signal sequences?
Definition
signal peptidases
Term
glycocalyx
Definition
oligosaccharides extending from proteins in the cell membrane, creating a sugary coat
Term
KDEL
Definition
lysine-aspartate-glutamate-leucine ER retention signal for ER resident proteins at their carboxyl ends
Term
pinocytosis
Definition
"little drinking" = non-selective uptake of extracellular material
Term
transcytosis example
Definition
mother's stuff going to her baby (early endosomes are sorting stations)
Term
example of endocytosed stuff staying in the cytosol
Definition
yolk nutrients (early endosomes are sorting stations)
Term
mtDNA lacks ___________ and is replicated throughout ___________. the universal code varies how?
Definition
histones, interphase. UGA -> tryptophan
Term
TOM and TIM complexes
Definition
protein Translocator on Outer/Inner Mitochondrial membrane
Term
intermediate filament structure
Definition
2 monomers wrap -> dimer, 2 dimers of opposite polarity w/ noncovalent bonds stagger -> tetramer, 8 tetramers! w/ noncovalent bonds
Term
cytoplasmic intermediate filaments
Definition
keratin in epithelium, neurofilaments in nerve cells, vimentin in CT, muscle and neuroglia
Term
Z lines have which types of cytoskeletal help?
Definition
intermediate filaments
Term
progeria
Definition
premature aging in children due to mutations of proteins of the nuclear lamins
Term
what energy form is required for microtubule growth?
Definition
GTP
Term
Taxol
Definition
excessive assembly of tubulin = anti-cancer drug
Term
colchicine
Definition
excessive disassembly drug with bad side effects, so not used for cancer like vincristine and vinblastine
Term
myosin-II
Definition
can slide actin filaments relative to each other, unlike myosin-I. (is important in cytokinesis and muscle contractions. myosin-I is in all cells)
Term
retinitis pigmentosa
Definition
kinesin defect in retinal cells
Term
herpes uses _________ to move along microtubules
Definition
kinesin
Term
lidocaine
Definition
inhibits kinesin movement in axons and therefore anterograde transport of neurotransmitters
Term
myosin-VI
Definition
mutations cause deafness in mammals
Term
primary cilia
Definition
sense and signal - do not move. defects -> polycystic kidney disease -> overproduction of kidney cells.
Term
where is the Na-K pump located in gut epithelial cells?
Definition
basal surface
Term
immunocytochemistry
Definition
using fluorescently-labelled antibodies to identify specific molecules
Term
peripheral heterochromatin
Definition
darker than euchromatin in rest of interphase nucleus
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