Cell Lecture Flashcards
Plasma Membrane
-Regulates transport into and out of the cell
-Glycocalyx, glycolipids, and glycoproteins (all of these work as cell surface receptors)
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Nucleus (except red blood cells)
-visualization due to heterochromatin (tightly packed DNA); stains darker and creates a dark rim around the nuclear area
-Chromatin packaging will allow us to understand cell activity & see it through H&E staining
-It can indicate the metabolic activity of the cell/protein production in order to see if the cell is malignant or tumorific
-nuclear receptors-steroid hormones
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Nucleolus
-rRNA production
-1-10 per cell (depends on the cell type)
Cytoplasm
- Cells described based on nuclear to cytoplasmic ration (N:C)
- Cytoplasm is distinct color based on organelle content
What’s in the cytoplasm?
- Mitochondria: ATP, Calcium ion storage, detoxification, steroids
- Smooth ER: Calcium ion storage, detoxification, steroid hormones
- Rough ER: protein production, secreted and plasma membrane-bound
- Polyribosomes: protein production, cytosolic and organelles
- Golgi Apparatus: posttranslational modifications, protein packaging
- Cytoskeletal proteins: structure and movement; IHC target
FORM = FUNCTION
Types and density of various organelles within a cell are what give/allow each cell to perform its duties
COLOR = CHEMISTRY
Types and density of various organelles within in a cell are what give it certain staining characteristics via LM
Euchromatin
- white
- open DNA that can be used
- can actively transcript
Heterochromatin
- black
- tightly coiled DNA
- inactive DNA
What colors are RNA and DNA in H&E and TEM?
H&E: RNA & DNA are blue
TEM: RNA & DNA are black
Nuclear Envelope
- paired membranes
- 30-50nm of perinuclear space
- not resolved with LM
- outer membranes is continuous with rER
- Nuclear pores perforate envelope; 70-80 nm openings
Nuclear Pore
Allow components to enter/leave nucleus
Cell Cycle
Visible with light microscope [LM]
Interphase
- Majority of time spent in this phase
- Euchromatin dominates in “busy”cell
- Interphase is when cell is a business cell and it carries out all its functions
Mitosis
- Prophase: chromatin condenses; dark nucleus (round)
- Metaphase: chromosomes align at equatorial plate
- Anaphase: division and separation of chromosomes
- Telophase: cytokinesis
Centrosome
- 2 centrioles arranged orthogonally (means in right angle to each other)
- It connects the microtubules to kinetochores to separate chromosomes
Tumorific cells
Malignant cells can exhibit extreme nuclear changes
Apoptosis
- Rapid programmed death
- Cell membrane remains intact
- Apoptotic bodies form and contain contents
- Phagocytized by macrophages
- Does not alert the immue system
This is a normal cell death
Necrosis
- Caused by trauma, toxins, infections, hypoxia, etc
- Cell membranes becomes leaky
- Mitochondria swell, burst
- Fluid rushes into cytoplasm; cellular contents leak out
- Immune system is alerted
Three Major Cytoskeleton Components
- Microfilaments: actin and myosin
- Microtubule: tubulin
- Intermediate filaments: keratin, vimentin
Cytoskeleton Functions
- Cell Adhesion
- Intracellular transport
- Extracellular transport
- Cell motility
- Cell division
- Cell structure
Microtubules
- All about movement
- 24-26nm diameter
- Found in cytoplasm
- Needs microtubule associated proteins (MAPs)
- Kinesin and dynein are motor proteins
- Examples: Cilia, flagella, centrosome, mitotic spindle, basal bodies
- Centriole: 9 triplets
Cilia
- motile
- movement
- 2 singlets in the center and is surrounded by 9 doublets
- 9+2
Basal Bodies
- Centrioles
- anchor for the cilia
- 9 triplets
Centrosome
- 2 centrioles arranged orthogonally
- Significant in cell division
- MTOC of mitotic spindle
