CHAPTER 3 BIO

• Squamous cells are thin, flat, and scaly
• Cuboidal cells are cube shaped cells that are found in the kidney and the pancreas
• columnar cells are column shaped cells and are taller than wide
• polygonal cells are irregular shaped with multiple sides
• stellate cells are star shaped cells that are found in the dermis and are responsible for wound healing
• spheroid cells are round to oval shaped
• discoidal cells are disc shaped cells
• fusiform cells are thick in the middle, tapered towards the end
• most cells are 10-15 mm in diameter
• an overly large cell cannot support itself and it may rupture
• when cells increase in diameter, volume increases more than surface area
• plasma membrane are the border of the cell
• the plasma membrane control what goes in and out, separate cells from the outside world, and defines cell boundaries
• 98 percent of membrane molecules are lipids
• phospholipids have two fatty acid tails that repel water and one hydrophilic head that attracts water
• phospholipids drift laterally to keep membrane fluid
• cholesterol holds phospholipids still and stiffens membrane
• cholesterol holds 20 percent of membrane lipids
• glycolipids contributes to glycocalyx
• glycocalyx is when carbohydrates coats on cell surface
• In integral protein, the hydrophilic connects to the cytoplasm and the hydrophobic passes through the lipid to the membrane
• In peripheral proteins, it is tendered to the cytoskeleton
• The function of the membrane protein consists of, receptors, being a second messenger, enzymes, cell adhesion molecules, and transport proteins
• the receptor binds
• the second messenger system communicates between cells that are receiving the chemical message
• channel proteins allows solutes to pass in and out of the cell
• ligand-gated channels responds to chemical messengers
• voltage-gated channels respond to charge channels
• mechanically-gated channels respond to physical stress on cell
• the carriers of membrane proteins bind solutes and transfer them across membrane
• cell-identity markers are proteins that are specific to a cell type and are used to identify cells
• cell-adhesion molecules link cell to extracellular material
• the glycocalyx is a fuzzy coat external to the plasma membrane
• carbohydrates are separated into glycoproteins and glycolipids
• glycocalyx main functions are: protection, cell adhesion, immunity to infection, defense against cancer, and embryonic development
• microvilli are best developed in cells specialized in absorption
• microvilli appear as fringe
• microvilli extension of the membrane from 1 to 2 mm
• cilia beats freely within cell layer at cell surface
• the cilia mucus will float on top of the saline layer