The Cell as a Unit of Health and Disease Flashcards
Structure of the cell primarily responsible for protection and nutrient acquisition
Plasma membrane
2 major components of the plasma membrane
Phospholipids and proteins
Plasma membrane proteins that are permanently attached to the plasma membrane
Integral membrane proteins (IMPs)
Plasma membrane proteins that span the entirety of the plasma membrane, with components extracellularly and components intracellularly
Transmembrane proteins (TPs)
Note: all TPs are IMPs, but not all IMPs are TPs
Plasma phospholipid usually found in the inner leaflet, used for scaffolding proteins and involved in intracellular signalling
Phosphatidylinositol
(mnemonic: IN
- INositol
- stays in the INner leaflet
- involved in INtracellular signalling)
Plasma phospholipid usually found in the inner leaflet, not usually used in scaffolding proteins and involved in apoptosis when traversing to the outer leaflet
Phosphatidylserine
(mnemonic: SERial killer
- SERine
- escapes from inner leaflet to outer leaflet to KILL cell (apoptosis)
Plasma phospholipids usually found in the outer leaflet, highly involved in cell-to-cell and cell-to-matrix interactions (communicators)
Glycolipids and sphingomyelins
Cell transport that solely requires movement across a concentration gradient, requiring no energy
Examples: hydrophobic molecules
Passive diffusion
Cell transport that requires a membrane transport protein to move molecules or ions against the concentration gradient, as seen in active transport or facilitated diffusion; require action from substrates on their BINDING SITES, and is usually never simultaneously open to the extracellular environment and the intracellular environment
Examples: Na-K pump
Carrier transport
Cell transport that requires a membrane transport protein to move molecules or ions against the concentration gradient, as seen in active transport or facilitated diffusion; these DO NOT require action from substrates as they have NO BINDING SITES, and is usually simultaneously open/closed to the extracellular environment and the intracellular environment
Examples: water movement through an aquaporin
Channel/pore transport
Cell transport that involved in continuous endocytotic/potocytotic uptake of molecular/ionic material into the cell
Fluid-phase uptake
Cell transport that involved in mediated endocytotic/phagocytotic/pinocytotic uptake of molecular/ionic material into the cell (requires mediated signalling)
Receptor-mediated uptake
Type of receptor-mediated uptake endocytosis utilizing clathrin-coating pits, also known as cell “drinking”
Pinocytosis
Type of fluid-phase uptake endocytosis mediated by non-coated plasma membrane invaginations called caveolae, highly involved in the regulation of transmembrane signalling and/or cellular adhesion, also known as cell “sipping”
Potocytosis
Non-coated plasma membrane invaginations involved in cell adhesion, transmembrane signalling, and potocytosis
Caveolae
Type of endocytosis of material into cell for lyses/storage
Phagocytosis
Emittance of material from inside the cell to outside the cell
Exocytosis
Endocytosis of material for storage and exocytosis of material into another environment
Transcytosis
Cytoskeletal proteins encompassing actin and myosin
Microfilaments
Cytoskeletal proteins encompassing lamins, vimentin, desmin, neurofilaments, GFAP, and cytokeratins
Intermediate filaments
Unique cytoskeletal proteins composed of alpha- and beta-tubulin
Microtubules
Unique cytoskeletal protein responsible for anterograde transport
Kinesin
Unique cytoskeletal protein responsible for retrograde transport
Dynein
Type of cell-cell interaction:
- involves occludin, claudin, zonulin, and catenin
- forms liquid-impermeable barriers
- present only in vertebrate organisms (invertebrates have septate junctions)
- maintain “cell polarity”, dividing apical from basal regions
Tight junctions or:
- occluding junctions
- zonula occludens (pl. zonulae occludentes)
Type of cell-cell interaction:
- involves desmosomes, desmoglein, hemidesmosomes, and other proteins of the cadherin family
- for cell adhesion
- major role in resisting shearing forces found in the simple and simple stratified epithelia
Anchoring junctions or:
- anchoring spots
- macula adherens (pl. maculae adherentes)
Type of cell-cell interaction:
- involves connexins (6 connexins form 1 connexon or hemichannel)
- for cell communication
- found only in animals (plants have plamodesmata)
Gap junctions or:
- communicating junctions
- nexus
- communicating spots
- macula communicans (pl. maculae communicantes)
Specific gap junction found in neurons
Synapse
Cell signaling to target nearby cells
Paracrine
Cell signaling to self
Autocrine
Special paracrine cell signaling that involves the transfer of across a synapse/nexus
Synaptic
Cell signaling to target cells of distant site via systemic circulation
Endocrine
Growth factor:
- function: mitogenic for keratinocytes and fibroblasts, stimulation of keratinocyte migration, stimulation of granulation tissue formation
- source: activated macrophages, salivary glands, keratinocytes, many other cells
Epidermal growth factor (EGF)
Growth factor:
- function: STIMULATES proliferation of hepatocytes and other epithelial cells
- source: activated macrophages, keratinocytes, many other cells
Transforming growth factor-alpha (TGF-a)
Growth factor:
- function: ENHANCES proliferations of hepatocytes and other epitherlial cells; increases cell motility
- source: fibroblasts, liver stromal cells, endothelial cells
Hepatocyte growth factor (HGF) or scatter factor
the enhancer of TGF-a
Growth factor:
- function: proliferation of endothelial cells; increases vascular permeability
- source: mesenchymal cells
Vascular endothelial growth factor (VEGF)
Growth factor:
- function: chemotaxis for inflammatory cells, smooth muscle cells, and fibroblasts; activates proliferation of fibroblasts and endothelial cells; stimulates ECM protein synthesis
- source: platelets, macrophages, endothelial cells, smooth muscle cells, keratinocytes
Platelet-derived growth factor (PDGF)
Growth factor:
- function: chemotactic and mitogenic for fibroblasts, stimulates angiogenesis and ECM protein synthesis
- source: macrophages, mast cells, many other cells
Fibroblast growth factors (FGFs)
Growth factor:
- function: chemotactic for leukocytes and fibroblasts, stimulates ECM protein synthesis, anti-inflammatory against acute inflammation
- source: platelets, T lymphocytes, macrophages, endothelial cells, keratinocytes, smooth muscle cells, fibroblasts
Transforming growth factor-beta (TGF-b)
Growth factor:
- function: stimulation of keratinocyte migration, proliferation, and differentiation
- source: fibroblasts
Keratinocyte growth factor (KGF)
Cells with the properties of SELF-RENEWAL and ASYMMETRIC DIVISION
Stem cells
