1
Q
dynein
A
In cilia and flagella, a large motor protein extending from one microtubule doublet to the adjacent doublet. ATP hydrolysis drives changes in dynein shape that lead to bending of cilia and flagella.
2
Q
actin
A
globular protein that forms the twisted double chains of microfilaments
3
Q
myosin
A
- A type of motor protein that associates into filaments that interact with actin filaments to cause cell contraction. Thicker than actin.
- Like dynein, myosin acts as a motor protein by means of projections that “walk” along the actin filaments.
- Part of contractile apparatus of MUSCLE cells
4
Q
pectin
A
Sticky polysaccharide that makes up the middle lamella.
5
Q
fibronectin
A
- An extracellular glycoprotein secreted by animal cells that helps them attach to the extracellular matrix.
- Fibronectin and other ECM proteins bind to cell-surface receptor proteins called integrins that are built into the plasma membrane.
6
Q
integrin
A
- Cell-surface receptor protein built into the plasma membrane; has 2 subunits.
- Span the membrane and bind on their cytoplasmic side to associated proteins attached to microfilaments of the cytoskeleton.
- Transmit signals btwn ECM and cytoskeleton; thus integrates changes occurring inside and outside the cell.
7
Q
lignin
A
- a complex organic polymer deposited in the cell walls of many plants, making them rigid and woody.
- Present in all vascular plants, but not in bryophytes.
- Relatively indigestible; accounts for more than a quarter of the dry mass of wood.
8
Q
suberin
A
- As cork cells mature, they deposit a waxy, hydrophobic material called SUBERIN in their walls and then die.
- B/c cork cells have SUBERIN and are usually compacted together, most of the periderm is impermeable to water and gases.
