Ch 6.2: A Tour of the Cell Flashcards
What are microfilaments?
thin solid rods made of actin (globular protein)
What is a cortex?
the outer cytoplasmic layer of a cell
What protein filament interacts with actin filaments?
myosin, which allows the filament to move
What are intermediate filaments?
only found in some animal cells, are specialized for bearing tension , and are permanent fixtures of cells (they do not break apart and reassamble)
What is a cell wall?
an extracellular structure of plant cells
What is the function of a cell wall?
provides protection, maintains shape, and prevents excessive water uptake
What are microfibrils?
made of cellulose (polysaccharide) are synthesized by an enzyme (cellulose synthase) and secreted extracellularly
What are the three layers of a cell wall?
primary cell wall, middle lamella, and secondary cell wall
What is the primary cell wall?
relatively thin and flexible, secreted first
What is the middle lamella?
thin layer between primary walls, containing polysaccharides called pectins
What is the secondary cell wall?
added between the plasma membrane and the primary cell wall
What is the extracellular matrix (ECM)?
the outer cover that surrounds an animal cell
What glycoproteins is the ECM made of?
collagen, proteoglycans, and fibronectin
What is integrins?
a receptor protein in the plasma membrane that binds to fibronectin and other EMC proteins
What is the function of an EMC?
an influential role in the lives of cells, can regulate a cell’s behavior by communication with a cell through integrins, and around a cell can influence the activity of genes in the nucleus
