prelim lesson 3 Flashcards
(118 cards)
1
Q
Nathansohn proposes the mosaic model: Membrane is a mosaic with lipid areas and areas with semipermeable gel, which would allow water
A
1904
2
Q
Overton develops concept of a lipid membrane. (Flaw: Lack of explanation for high permeability of water.) Also proposed idea of
active transport requiring energy.
A
1895-1899
3
Q
:Davson-Danielli model proposes that the phospholipid bilayer is surrounded by protein layers on either side.
A
1935
4
Q
Singer-Nicholson’s Fluid Mosaic Model: Membrane is a fluid structure with a “mosaic” of proteins embedded in or attached to the phospholipid bilayer.
A
1972
5
Q
- Semipermeable
- Permeable to water, gases, nonpolar substances
- More permeable to K+ rather than Na+
A
CELL MEMBRANE (PLASMALEMMA)
6
Q
Enveloped delimiting the cell from the surroundings
A
CELL MEMBRANE (PLASMALEMMA)
7
Q
Protects the cell (Guardian of the cell)
A
CELL MEMBRANE (PLASMALEMMA)
8
Q
Regulates movement of substances in/out of the cell
* Attachment for cytoskeleton
A
CELL MEMBRANE (PLASMALEMMA)
9
Q
Receives and sends out stimuli
* Provide binding sites and receptors
* Allow cell to cell recognition
A
CELL MEMBRANE (PLASMALEMMA)
10
Q
FACTORS THAT DETERMINE PERMEABILITY OF THE CELL
MEMBRANE:
A
- Temperature
- Type of solutes present
- Level of cell hydration
11
Q
- 8-10nm thick (Not seen in LM)
- Trilaminar structure
A
CELL MEMBRANE
(PLASMALEMMA)
12
Q
Mainly made up of
phospholipids and protein
molecules
A
CELL MEMBRANE
(PLASMALEMMA)
13
Q
- 1⁄2 the mass of the cell membrane
A
Protein molecules
14
Q
- Perform in transport of substances across the membrane
A
Protein molecules
15
Q
span the whole thickness
A
Integral proteins (Transmembrane proteins):
16
Q
Tight attachment using hydrophobic interactions
A
Integral proteins (Transmembrane proteins):
17
Q
at the outer or inner surface (leaflets)
A
Peripheral proteins:
18
Q
Has loose attachment using electrostatic interactions
A
Peripheral proteins:
19
Q
Found in irregular spaces between phospholipid molecules
A
Cholesterol molecules
20
Q
Confers membrane fluidity and permeability to water-soluble
substances
- Membrane buBer
A
Cholesterol molecules
21
Q
Present in some cells
A
Glycocalyx
22
Q
Loose carbohydrate coat of
the cell surface Thin layer of
amorphous electron-dense
material on cell surface
A
Glycocalyx
23
Q
- Glycolipids + glycoproteins
A
Glycocalyx
24
Q
- Cell-to-cell
recognition - Cell-to-cell
adhesion - Immunological
response
A
Glycocalyx
25
Trilaminar entity that comprises the cell membrane and makes
up or envelopes all the other membrane-containing structures
in the cell
UNIT MEMBRANE
26
Variation in thickness is due to protein content
UNIT MEMBRANE
27
* Disk-shaped
* For tight intracellular adhesion
Macula Adherens (Desmosomes)
28
* Ring-shaped
Zonula adherens
29
Increases surface area for contact
Zonula adherens
30
Equivalent in cardiomyocytes is Fascia adherens
Zonula adherens
31
Stratum basale/germinativum is separated from the dermis by the basement membrane (basal lamina) and attached to the basement membrane by the
hemidesmosomes
32
* Barrier to movement of proteins across membranes
Zonula Occludens
33
Divides cell into apical and basolateral side
Zonula Occludens
34
Bridge for sharing of small molecules between cells
Gap junctions
35
Enclosed in a cell membrane
CYTOPLASM
36
* Homogenous substance
* Viscid, translucent, and colloidal
* Water is 70% or more by volume
Cytoplasmic matrix
37
Permanent structures
Organelles`
38
Perform certain specific functions within a cell
Organelles
39
Temporary fixtures
* Accumulation of pigments, lipids, etc
Inclusions
40
Form the cytoskeleton or supporting framework
Fibrillar structures
41
Increasing in cytoplasmic matrix viscosity = increase in fibrillar elements
Fibrillar structures
42
Powerhouse of the cell
MITOCHONDRIA
43
Aggregate in areas where energy is needed
MITOCHONDRIA
44
delimits
mitochondrion from cytoplasmic
matrix. Freely permeable to most
molecules
Outer membrane/leaflet:
45
infolded to form
shelf-like tubular structures
Inner membrane:
46
Increase surface area
Cristae
47
Space between outer and inner
leaflets
Intermembranous space
48
which extends into cristae as
intracristal spaces
49
Granules rich in magnesium and
calcium
Mitochondrial Matrix
50
Messenger and transfer RNAs
Mitochondrial Matrix
51
cluster of ribosomes connected by mRNA; actively translating the mRNA; this only happens in prokaryotes
Polyribosomes/polysomes
52
* Free in the cytoplasm
Ribosomes
53
* Attached to the surface of the ER
Ribosomes
54
__ is the large ribosomal subunit in prokaryotes, while ___ is the large ribosomal subunit in eukaryotes
50s; 60s
55
__prokaryotes is the small ribosomal unit in prokaryotes while __ is the small ribosomal subunit in - eukaryotes
30s; 40s
56
enzyme
for peptide bond formation
Peptidyl synthetase
57
Most extensive membranous
structure
ENDOPLASMIC RETICULUM
58
Consists of interconnecting
tubules, vesicles, and flattened
sacs (cisternae)
ENDOPLASMIC RETICULUM
59
Supporting structure for the
cytoplasm
ENDOPLASMIC RETICULUM
60
Present in all cells but seen only
in EM and special preparations
ENDOPLASMIC RETICULUM
61
* Thinner than plasmalemma
Membranes
62
* capable of remodeling, disassembly and assembly
Dynamic organelle
63
Synthesis and transport of most membrane- bound proteins
RER (rough)
64
* Proteins transferred to Golgi Complex through transfer vesicles
RER (rough)
65
Lipid synthesis (phospholipids, cholesterol, steroids)
SER (smooth)
66
Semi circularly stacked layers of membrane-bound, flattened tubes
GOLGI COMPLEX/ APPARATUS/ BODY
67
rounded dilatations of cisternae filled with fluid
Vesicles
68
forming face
Cis face
69
maturing face
Trans face
70
Membrane bound Chemical-containing pouches
LYSOSOMES
71
With hydrolytic enzymes (hydrolases) from Golgi
LYSOSOMES
72
Digestion of particulate material (bacteria, dead and senescent
[dying] cells) from environment by phagocytosis
Heterophagy
73
By neutrophils and macrophages (aka phagocytes)
Phagocytosis
74
Digestion of unneeded/senescent cell organelles
Autophagy
75
they contain oxidases and catalases
PEROXISOMES
76
by removing hydrogen atoms that are
transferred to molecular oxygen, producing H2O2
Oxidases-
77
immediately breakdown H2O2- potentially damaging to
cell
Catalase
78
Usually near the nucleus,
surrounded by Golgi
CENTROSOME
79
minute, short,
cylindrical bodies surrounded
by granular structures
(centriolar satellites)
Centrioles
80
Determine the shapes of cell
CYTOSKELETON
81
* Solid in cross-section
* Not easily assembled and disassembled
Intermediate filaments
82
* Can be assembled and disassembled easily
Microfilaments
83
* Involved in cell membrane activities (exocytosis and endocytosis)
* Associated with movement of organelles
Microfilaments
84
* Assembled in the centrosome
* Movement of organelles
Microtubules
85
* Internal support of the cell
* Forms wall of centrioles, axoneme
Microtubules
86
* Surrounded by microtubule- associated proteins (MAPs)
Microtubules
87
main cell type in epidermis; primarily for protection of epithelial cells
Keratin
88
characteristic of muscle cells; often at smooth muscles; forms bundles in smooth muscles; seen around
Desmin
89
differentiated from mesenchyme
Vimentin
90
characteristic of nerve cells; at cell body and neuron processes (extensions);
Neurofilaments
91
- integral support of neuroglial cells
Glial filaments
92
store lipid
Adipocytes
93
* Can be fixed by gulatraldehyde and osmic acid
Fat droplets (lipid droplets)
94
Storage form of carbohydrates
Glycogen (glycogen granules)
95
Abundant in liver and muscle cells
Glycogen (glycogen granules)
96
Two sizes of glycogen
* Large (__) particles: 90nm
* Small (__) particles: 20-30 nm
alpha; beta
97
formed by melanocytes
Melanin
98
Also in nerve cells of substantia nigra, locus coeruleus in the brain, and
pigment epithelium of the retina
Melanin
99
Distinguished by iron stain: Prussian blue
Hemosiderin
100
* Iron-containing pigment
* Brown pigment responsible of RBCs color
Hemosiderin
101
Form of granules in cells such as those in spleen that phagocytose
senescent RBCs
Hemosiderin
102
Aka “secretory granules”
Characteristic of secretory epithelial cells
Zymogen Granules
103
At interstitial cells of Leydig (for testosterone production) and Sertoli cells of testes
Crystals
104
Numerous in cytoplasm of phagocytes of lungs (pulmonary alveolar
macrophages; dust cells)
Dust Particles
105
* Common among smokers and city dwellers
* Brown to black structures
Dust Particles
106
Separated from cytoplasm by a nuclear envelope
NUCLEUS
107
Largest organelle in the cell
NUCLEUS
108
Filled with a homogenous substance (nuclear matrix)
NUCLEUS
109
genes in its chromosomes contain information needed for synthesis of all proteins and nucleic acids
Data bank of the cell-
110
Command center of the cell
NUCLEUS
111
(Largest structure with the cell)
Nuclear envelope/membrane
112
thin film of proteins from nuclear pore complex that covers
the nuclear pore
Pore diaphragm =
113
expressed genes; in the
process of producing mRNAs and tRNAs
Extended
114
areas–condensed because of histones;
“heterochromatin”, not expressed
Condensed
115
Inside the nucleus
Present at interphase ONLY
Nucleoli (Nucleolus)
116
Where chromosomes with nucleolar organizers (gene sequence for rRNA) gather
Nucleolar organizing region
117
Electron-dense filaments
Pars fibrosa
118
Circular pale area surrounded by pars fibrosa
Nucleolar organizing region
