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Cytology 1 flash cards
Flash cards for cytology lecture 1
75
Histology
Professional
08/22/2011

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Term
Four basic tissue types
Definition
1. epthelia
2. connective tissue
3. muscle
4. nerve
Term
four common features of cells
Definition
1. surrounded by membrane
2. have zero - many nuclei
3. contain organelles
4. contain inclusions
Term
2 major components of cell (name the third that some times included)
Definition
1. nucleus
2. cytoplasm
3. plasmamella/ plasma membrane (sometimes)
Term
four important concepts about plasma membrane
Definition
1. not homogeneous
2. constant dynamic flux
3. highly asymmetrical
4. shame of surface is formed by cytosketetal components
Term
thickness of plasma membrane
Definition
8-10 nm
Term
three layers of unit membrane ( and what do they face)
Definition
1. inner leaflet - faces cytoplasm
2. outer leaflet - face extracellular environment
3. electron lucent intermediate zone
Term
three components of all cell membranes
Definition
1. lipids
2. proteins
3. carbohydrates
Term
what are the 3 membrane lipids?
Definition
1. phospholipids
2. cholesterol
3. glycolipids
Term
phospholipids - summary
Definition
1. most abundant
2. arranges symmetrically
3. amphipathic
Term
cholesterol - summary
Definition
1. second major lipid
2. restricts diffusion through membrane
3. reduces membrane fluidity at high temperatures
4. prevents crystallization at low temperatures
Term
glycolipids - summary
Definition
1. found on outer leaflet
2. cell-cell/matrix interactions
Term
four major membrane phospholipids and leaflet they're on (name the fifth and what it's important in as well)
Definition
1. sphingomyelin - outer leaflet
2. phosphatidylcholine - outside leaflet
3. phosphatidylserine - inside leaflet
4. phosphatidylethanolamine - inside leaflet
5. phosphatidylinositol - important in cell signaling
Term
what happens if a phosphatidylethanolamine is on the outer leaflet
Definition
cells is signaling for apoptosis
Term
what region of the membrane does cholesterol accumulate
Definition
cholesterol stiffening region, below the polar head groups
Term
what structural attributes help cholesterol perform its functions
Definition
rigid ring structure
Term
glycolipids are found on what leaflet?
Definition
outer leaflet
Term
blood group antigens A, B, & O are examples of what membrane lipid?
Definition
glycolipids
Term
specialized membranes with high concentrations of sphingolipids and cholesterol that associate with different protein or signaling molecules
Definition
lipid rafts
Term
three functions of lipid rafts
Definition
1. Membrane sorting and trafficking
2. Cell polarization
3. Signaling molecules
Term
lipid rafts are associated with what diseases?
Definition
1. Alzheimers
2. Parkinsons
3. HIV
4. Bacterial infections
5. cancer - pathogens hijack these to get into cells
Term
Is the lipid raft thicker or thinner than rest of the plasma membrane and why?
Definition
thicker - longer fatty acid tails
Term
two functions of membrane lipids
Definition
1. responsible for semi-permeable characteristics of membrane
2. serve as signaling molecules - usually phosphorylation involved.
Term
___ perform specialized functions of membranes
Definition
proteins
Term
two types of membrane proteins
Definition
1. integral proteins - majority; single or multi pass
2. peripheral - associate via ionic interactions
Term
examples of peripheral proteins (a) outside of cell and (b) inside of cell
Definition
(a) fibronectin
(b) spectrin
Term
Name of method in which integral proteins can be visualized
Definition
freeze-fractured
Term
4 things that membrane protein mobility is effected by
Definition
1. self-assembly of proteins into large aggregates
2. interactions with molecules outside of the cell
3. interactions with molecules inside cell - i.e. cytoskeleton
4. interaction with surface proteins of other cells
Term
denervation supersensitivity example
Definition
If motor nerve is severs, ACh receptors are spread over plasma membrane instead of at motor end plate with a intact nerve
Term
6 functions of membrane proteins
Definition
1. receptors
2. pumps
3. channels
4. enzymes
5. linkers
6. structural proteins
Term
____ are confined to the outer leaflet and associate with membrane proteins and lipids
Definition
carbohydrates
Term
on the cell surface, the carbohydrate component forms the ____
Definition
glycocalyx
Term
the glycocalyx consists of __(a)__ ___(b)___ side chains link to most __(c)___ and only some __(d)___
Definition
(a) polar
(b) oligosccaride
(c) proteins
(d) lipids
Term
glycocalyx are extremely prominent on what cells?
Definition
those lining the GI tract
Term
four functions of glycocalyx
Definition
(1) trapping and digestion of molecules
(2) cell-cell recognition in development and immune response
(3) cell-cell communication
(4) protection of cell surface
Term
5 general functions of plasmalemma
Definition
1. preserves cell's integrity
2. permeability
3. conduction of action potential (nerve and muscle)
4. respond to external stimuli
5. contains receptors for cell-cell/matrix interactions
Term
basic function of nucles
Definition
synthesis of nucleic acids (DNA and RNA)
Term
Basic morphology of nucleus
(a) shape
(b) size
(c) number per cell
(d) location
(e) DNA content
(d) DNA complexed with proteins = ______
Definition
(a) round, ellipsoid, unfolded, lobulated
(b) varies
(c) none - multi
(d) central, basal, eccentric
(e) haploid, diploid, polyploid
(d) chromatin
Term
5 components of nucleus
Definition
1. nuclear envelope
2. nuclear pores
3. nuclear lamina
4. chromatin
5. nucleolus
Term
three components of nuclear envelope ( and faces where)
Definition
1. outer nuclear membrane - faces cytoplasm
2. inner nuclear membrane - faces nuclear matrix
3. perinuclear cisternae - space between two
Term
outer nuclear membrane
Definition
1. faces cytoplasm
2. continuous and shares biochemical and functional properties with rER
3. CAN have ribosomes
Term
inner nuclear membrane
Definition
1. faces nuclear matrix
2. distinct from outer NM and rER
supported by nuclear lamina
Term
inner and outer nuclear membranes are continuous where?
Definition
nuclear pores
Term
Nuclear pore function
Definition
1. channels between nucleus and cytoplasm
2. small polar molecules, ions, proteins, and RNA can pass
3. larger molecules (RNA, ribosomal subunits and proteins) are transported by active transport
Term
number of pores per nucleus corresponds to ___
Definition
cell's metabolic activity
Term
Nuclear pore structure
Definition
cylindrical shape
outer diameter - 120 nm
inner diameter - 70-80 nm
maximum size of passive transport - 9 nm
Term
arrangement of proteins surround a pore between the inner and outer nuclear membranes
Definition
Nuclear Pore Complex (NPC)
Term
subunit of nuclear pore complex
Definition
nucleoporins - 700 - 1000 polypeptide proteins
Term
structure of Nuclear Pore Complex
Definition
(1) 8 protein subunits consisting of (a) annular subunits and (b) column sub units
(2) two rings - one nuclear and one cytoplasmic
(3) luminal subunit - anchors 8 protein subunits
(4) protein filaments to rings - nuclear cage
(5) central granule or plug - aka central transporter
Term
6 functions of Nuclear Lamina
Definition
1. gives shape and stability to nuclear envelope
2. organize interphase nucleus
3. structural link between chromatin and nuclear envelope
4. dissolution and reformation of nuclear envelop during cell division
5. organizing cytoskeleton
Term
Is mutations of Lamin A or Lamin B surivable?
Definition
Lamin B mutations are survivable
Term
Location of the nuclear lamina
Definition
between inner nuclear membrane and peripheral heterochromatins
Term
components of nuclear lamina
Definition
lamins form dimers that associate heat to tell and side by side
Term
what causes dissolution of nuclear lamina during mitosis?
Definition
lamin phosphorylation
Term
Progeria is (a) what and (b) cause by a mutation in what?
Definition
(a) children aging really quickly
(b) Lamin A mutation
Term
What component of the Nucleus is a complex of DNA, histone and non-histone proteins?
Definition
Chromatin
Term
What are the 2 types of chromatin in the interphase nucleus?
Definition
(1) heterochromatin - electron dense portions; not being transcribed
(2) euchromatin - uncoiled that are being transcribed.
Term
3 stages of packaging of chromatin in nucleus
Definition
(1) nucleosome -
(2) 30nm DNA threads
(3) Chromosomes
Term
Nucleosome
Definition
(1) 11nm wide "beads on a string"
(2) 8 proteins - 2pairs of 4 types of histones
(3) DNA makes 1.75 turns around october
(4) string is linker DNA
Term
30 nm DNA threads
Definition
nuclesomes form by coiling 6 nucleosomes per turn of coil
are bounded by another type of histone
Term
genome
Definition
number of chromosomes in somatic cell
(b) species specific
(c) humans have 46
Term
karyotype
Definition
standard map of banding pattern of chromosomes
Term
autosomes
Definition
non sex chromosomes
Term
sex chromosomes
Definition
1 per cell - xx or xy
Term
barr body
Definition
highly coiled extra x chromosome that is inactive. looks like drumstick in light microscopy
Term
number of chromosomes in
(a) diploid
(b) haploid
(c)polyploid
(d) aneuploidy
(e) trisomy
(d) monosomy
Definition
(a) 46
(b) 23
(c) more than one complement of chromosomes
(d) any deviation from the normal number
(e) third chromosome of one type
(d) absence of membrane of a chromosome pair
Term
diseases from aneuploidy - give altered chromo
(a) down's syndrome
(b) klinefelter's syndrome
(c) turners syndrome
Definition
(a) 21
(b) xxy (47 vs 46 total )
(c) absence of sex chromosome
Term
component of nucleus that is the site of ribosomal transcription an synthesis
Definition
nucleolus
Term
composition of nucleolus
Definition
rich in rRNA and protein
Term
Nuclear organizing regions
Definition
(a) regions of 10 interphase chromosomes that contain genes that encode rRNA and reorganize nucleoli
(b) 13, 14, 15, 21, 22
Term
3 regions of nucleolus
Definition
(1) pale staining region - fibrillar center
(2) pars fibrosa - dense fibrillar region
(3) pars granulosa - granular component
Term
Difference between RNA and DNA
Definition
(1) RNA uses ribose sugar instead of deoxyribose
(2) uracil instead of thymine
Term
3 types of RNA
Definition
(1) mRNA - amino acid coding region
(2) tRNA - transfers amino acid to ribosome
(3) rRNA - forms ribosomes
Term
Structure of Ribosomes
Definition
(1) Large subunit (60s) of - 5S, 5.85S, and 28S
(2) small subunit (40s) of 18S and 33 proteins
Term
3 events of ribosome synthesis occurring in nucleolus
Definition
(1) transcription of rDNA to pre-rRNA
(2) association of pre-rRNA with ribosomal proteins to form ribonucleoproteins
(3) cleavage of pre-rRNA into 28s, 18s, and 5.8s
Term
which part of the ribosome is NOT synthesized in the nucleolus
Definition
5s of the large subunit
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