Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
23 Cards in this Set
- Front
- Back
|
Advantage of multicellularity |
-cells can perform different functions -maintain homeostasis + total function -specialization -cooperation |
|
|
Processes required to create tissues and organs (6) |
1. cell connections (ECM + communication - signal transduction) 2. Cell division 3. Cell growth 4. Differentiation 5. Migration 6. Apoptosis |
|
|
Cell connections that allow multicellularity to occur: |
-extracellular matrix (ECM) -Cell junctions |
|
|
Complex meshwork on outside of cells: |
ECM -interstitial ECM -Basal lamina |
|
|
Examples of cells in ECM |
Endothelial cells - attached to ECM on one side, open to vessel lumen on other side Fibroblasts - surrounded by ECM in connective tissues |
|
|
ECM functions (4) |
1. strength 2. structural support 3. organization 4. cell signaling |
|
|
Interstitial fluid |
solution that bathes and surrounds the cells of multicellular animals -nutrients -waste removal |
|
|
Major macromolecules |
Proteins -Adhesive (fibronectin and laminin) -Structural proteins (collagen and elastin) Polysaccharides -gel-like matrix |
|
|
Proteins in the ECM |
Adhesive: -Fibronectin - connects cells to ECM + organizes components -Laminin - Connects + organizes components in basal lamina Structural: -Collagen - forms large fibres/fibrous network - tensile strength -Elastin - elastic fibres in ECM that can stretch and recoil |
|
|
Collagen |
-A family of proteins -made of 3 wound alpha chains -stiff or loose -tensile strength -Main protein in: bones, cartilage, tendons and skin -lines blood vessels and internal organs |
|
|
Elastin |
-provides elasticity -important in lungs and blood vessels -covalent cross links between elastin fibres (keeps attached) |
|
|
GAG's |
Polysaccharides -> major structural component of ECM -most abundant type -highly negative (attracts + ions and water) -linked to core proteins |
|
|
Proteoglycans |
glycosylated proteins |
|
|
Glycosylation |
-occurs in ER and Golgi -Attachment of sugar to protein -how proteoglycans of ECM are made |
|
|
Plant cell wall |
-organized ECM -tensile strength, resistance to compression -thicker, stronger + more rigid than animal ECM |
|
|
How do cells exist as a multicellular community (tissues/organs)? |
-linked together by ECM -cells perform own function, interact to accomplish organism's bodily functions |
|
|
Cell junctions |
cell to cell linkages in ECM |
|
|
Types of anchoring junctions (3) |
1. Anchoring junctions: anchor cells to one another or ECM 2. Tight junctions: seal cells together into a tissue 3. Gap junctions: allow cells to communicate directly with each other |
|
|
What membrane proteins do anchoring junctions rely on? |
Cell adhesion molecules (CAM's) -Cadherin and Integrins |
|
|
Cadherins |
-cell to cell junctions -dimer w/ identical subunits -binding requires Ca2+ -linked proteins inside cell connect cadherins to actin/intermediate filaments |
|
|
Integrins |
cell to cell junctions -bind ECM components -linker proteins inside cell connect integrins to actin or intermediate filaments |
|
|
Tight junctions |
-forms a tight seal between adjacent cells -prevents extracellular leakage -forms impermeable barrier -formed from membrane proteins: occludin and claudin - form interlaced strands in plasma membrane -bind to strands in neighbor cells |
|
|
Gap junctions |
-form intracellular channels that allow the passage of small solutes (ions, small molecules) -allows cells to share metabolites and directly signal eachother -composed of connexin - membrane protein -6-6 connexon |
