The Cell as a Unit of Health and Disease

Question 1

Structure of the cell primarily responsible for protection and nutrient acquisition

Answer 1

Plasma membrane

Question 2

2 major components of the plasma membrane

Answer 2

Phospholipids and proteins

Question 3

Plasma membrane proteins that are permanently attached to the plasma membrane

Answer 3

Integral membrane proteins (IMPs)

Question 4

Plasma membrane proteins that span the entirety of the plasma membrane, with components extracellularly and components intracellularly

Answer 4

Transmembrane proteins (TPs)

Note: all TPs are IMPs, but not all IMPs are TPs

Question 5

Plasma phospholipid usually found in the inner leaflet, used for scaffolding proteins and involved in intracellular signalling

Answer 5

Phosphatidylinositol

(mnemonic: IN
- INositol
- stays in the INner leaflet
- involved in INtracellular signalling)

Question 6

Plasma phospholipid usually found in the inner leaflet, not usually used in scaffolding proteins and involved in apoptosis when traversing to the outer leaflet

Answer 6

Phosphatidylserine

(mnemonic: SERial killer
- SERine
- escapes from inner leaflet to outer leaflet to KILL cell (apoptosis)

Question 7

Plasma phospholipids usually found in the outer leaflet, highly involved in cell-to-cell and cell-to-matrix interactions (communicators)

Answer 7

Glycolipids and sphingomyelins

Question 8

Cell transport that solely requires movement across a concentration gradient, requiring no energy

Examples: hydrophobic molecules

Answer 8

Passive diffusion

Question 9

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

Answer 9

Carrier transport

Question 10

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

Answer 10

Channel/pore transport

Question 11

Cell transport that involved in continuous endocytotic/potocytotic uptake of molecular/ionic material into the cell

Answer 11

Fluid-phase uptake

Question 12

Cell transport that involved in mediated endocytotic/phagocytotic/pinocytotic uptake of molecular/ionic material into the cell (requires mediated signalling)

Answer 12

Receptor-mediated uptake

Question 13

Type of receptor-mediated uptake endocytosis utilizing clathrin-coating pits, also known as cell “drinking”

Answer 13

Pinocytosis

Question 14

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”

Answer 14

Potocytosis

Question 15

Non-coated plasma membrane invaginations involved in cell adhesion, transmembrane signalling, and potocytosis

Answer 15

Caveolae

Question 16

Type of endocytosis of material into cell for lyses/storage

Answer 16

Phagocytosis

Question 17

Emittance of material from inside the cell to outside the cell

Answer 17

Exocytosis

Question 18

Endocytosis of material for storage and exocytosis of material into another environment

Answer 18

Transcytosis

Question 19

Cytoskeletal proteins encompassing actin and myosin

Answer 19

Microfilaments

Question 20

Cytoskeletal proteins encompassing lamins, vimentin, desmin, neurofilaments, GFAP, and cytokeratins

Answer 20

Intermediate filaments

Question 21

Unique cytoskeletal proteins composed of alpha- and beta-tubulin

Answer 21

Microtubules

Question 22

Unique cytoskeletal protein responsible for anterograde transport

Answer 22

Kinesin

Question 23

Unique cytoskeletal protein responsible for retrograde transport

Answer 23

Dynein

Question 24

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

Answer 24

Tight junctions or:

• occluding junctions
• zonula occludens (pl. zonulae occludentes)

Question 25

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

Answer 25

Anchoring junctions or:

• anchoring spots
• macula adherens (pl. maculae adherentes)

Question 26

Type of cell-cell interaction:

• involves connexins (6 connexins form 1 connexon or hemichannel)
• for cell communication
• found only in animals (plants have plamodesmata)

Answer 26

Gap junctions or:

• communicating junctions
• nexus
• communicating spots
• macula communicans (pl. maculae communicantes)

Question 27

Specific gap junction found in neurons

Answer 27

Synapse

Question 28

Cell signaling to target nearby cells

Answer 28

Paracrine

Question 29

Cell signaling to self

Answer 29

Autocrine

Question 30

Special paracrine cell signaling that involves the transfer of across a synapse/nexus

Answer 30

Synaptic

Question 31

Cell signaling to target cells of distant site via systemic circulation

Answer 31

Endocrine

Question 32

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

Answer 32

Epidermal growth factor (EGF)

Question 33

Growth factor:

• function: STIMULATES proliferation of hepatocytes and other epithelial cells
• source: activated macrophages, keratinocytes, many other cells

Answer 33

Transforming growth factor-alpha (TGF-a)

Question 34

Growth factor:

• function: ENHANCES proliferations of hepatocytes and other epitherlial cells; increases cell motility
• source: fibroblasts, liver stromal cells, endothelial cells

Answer 34

Hepatocyte growth factor (HGF) or scatter factor

the enhancer of TGF-a

Question 35

Growth factor:

• function: proliferation of endothelial cells; increases vascular permeability
• source: mesenchymal cells

Answer 35

Vascular endothelial growth factor (VEGF)

Question 36

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

Answer 36

Platelet-derived growth factor (PDGF)

Question 37

Growth factor:

• function: chemotactic and mitogenic for fibroblasts, stimulates angiogenesis and ECM protein synthesis
• source: macrophages, mast cells, many other cells

Answer 37

Fibroblast growth factors (FGFs)

Question 38

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

Answer 38

Transforming growth factor-beta (TGF-b)

Question 39

Growth factor:

• function: stimulation of keratinocyte migration, proliferation, and differentiation
• source: fibroblasts

Answer 39

Keratinocyte growth factor (KGF)

Question 40

Cells with the properties of SELF-RENEWAL and ASYMMETRIC DIVISION

Answer 40

Stem cells