Cells and Tissues Flashcards
Cholesterol’s major function in cell membrane:
Fluidity
Hepatocytes have how many nuclei?
up to 2
_______ and ______ are multinucleated
Osteoclasts and muscle fibers
Euchromatin vs heterochromatin
E: Loose and transcribed (stains light)
H: Dense and not transcribed (stains dark)
Standard tissue preparation consists of which staining?
Hematoxylin and Eosin
Hematoxylin
It is basic (+) and is attracted to the negatively charged backbone of DNA/RNA, dyes the nucleus blue
Eosin
it is negatively charged and acidic (-) and will dye the cytoplasm pink
The space between inner and outter membranes of the nuclear envelope
Cisterna
Shelf like folds in mitochondria
What is their function?
Cristae
Increase surface area for ATP production
Microtubules - vs +
- end is closer to the nucleus
+ end grows out towards the cell membrane
Kinesin
Walks from negative to positive end
Dynein
Walks from positive to negative end
Major stuctures made from microtubules
Flagella and cilia
Microtubules are made up of:
Alpha-tubulin
Beta-tubulin
2 types of actin
G-actin - globular
F-actin - FIlamentous
Light microscopy vs electron microscopy magnification
LM: 2,000 X
EM: 1,000,000 X
Transmission vs scanning EM
Transmission: Image viewed on a flouresecent screen, internal structures are viewed
Scanning: Image viewed on monitor, surface is viewed, 3 D specimen
Fixation
Preserve tissue woth formalin
Embedding
Uses paraffin
Order of tissue preparation
Fixation
Embedding
Sectioning
Staining
Histological sections:
Cross
Longitudinal
Tangential - off to the side or at an angle
Cell memranes are not visualized by ______ microscopy but is visualized as ______ in ______ microscopy
Light
a trilaminar structure
Electron
Two molecule types that are not stained by dye
Lipids and glycogen
They appear white or are lost in the process
Which organelle initiates cell apoptosis
Mitochondria
Ribosomes and sub units
Consist of small subunits and large subunits
Small subunit contains 1 mRNA
Large contains 2 mRNA
Ribosomes can be found attacher to:
RER and outer nuclear membrane
Ribosomes sit on the _____ surface of RER
Cytoplasmic
Unfolded protein response
Leads to cell death if there is an accumulation of unfolded or misfolded proteins
the nuclear side of Golgi apparatus and is in close proximity to ER
cis-Golgi network
The portion of Golgi whic is closer to the cell membrane
trans-Golgi network
Function of the Golgi apparatus
Post translational modification - activate proteins
Elaborates membrane lipids
Produces lysosomes
primary, secondary and tertiary lysosomes
1: Newly formed, no digested material
2: larger, heterogeneous, contain ingested material
3: Oldest and present in old cells (nerve and cardiac cells)
Autolysis
When lysosomes spill enzymatic contents which lead to cell death
Peroxisomes
Mainly perform oxidative reactions
Peroxisomes are most prominent in which cell types?
Hepatocytes, proximal tubule cells of kidney
In actin filaments, the fast growing end is referred to as the ___ end and the slow growing is referred to as a the ___ end
+
-
____ are composed of Actin
Microvilli
Anterograde transport
From Golgi to membrane
Retrograde transport
From membrane to Golgi
Smooth ER functions
Lipid synthesis
Detoxification of compunds
_________ association is important in maintaining biconcave shape of red blood cell.
Spectrin-actin
Ribosomal which are docked in the RER are crucial for:
Synthesis and export of proteins
Free ribosomes function
Protien synthesis for local needs
Cytoplasmic basophilia
Ribosomes stain blue because the RNA (-) attracts basic hematoxylin (+)
In cells that actively produce protein, the cytoplasm appears blue because there is an abundance of ribosomes
