Chapter 7 Flashcards
Fluid Mosaic Model
The Most Widely Accepted Membrane Model. Fluid refers to the ability of it’s components to move around and Mosaic means it has a Patchy Appearence.
Phospholipids
Arranged in two layers called a BLAYER with the Hydrophillic Heads (Water Loving) pointing in opposide directions because water is in and outside of the cell. The Hydrophobic (Water Fearing) Tails are insulated from the water.
Membrane Proteins
Embedded in the Phospholipid Bilayer and can move about the Bilayer.
Integral Protein
Extends into the Hydrophobic Region
Peripheral Protein
Not embedded but bound to the surface of the membrane. Serve as passages for molecules to move accross the membrane. Transfer Proteins. May be enzymes or send signals.
Signal Transduction
Joins cells together.
Serves as ID tag.
Recognition Proteins
Attach to the ECM.
Attach the membrance to the cytoskeleton.
Cholesterol
Found among hydrophobic tails in animal cells.
Beleived to aid in stabilizing the membrane.
Carbohydrates -
Oligosaccharides
(Short Polysaccharides)
Found attached to Lipids, Glycolipids, or Proteins
Cell to Cell Recognition.
Important in Embryonic development and Immunity.
Diffusion
The net movement of molecules by there own kinetic energy from an area of higher concentration to an area of lower concentration.
Concentration Gradient
Exsists when there is a difference in the concentration of molecules in two areas.
In diffusion moleculs move _________________.
down with the conentration gradient.
Lipid Soluable (Steriods, hormones, oxygen, carbon dioxide) pass ___________________.
directly through the lipid bilayer.
Water soluable molecules and ions ___________________.
pass through pores made of proteins.
Osmosis
The diffusion of water across a differentially permeable membrane.
Differentially Permeable Membrane
Some molecules can pass and some can not.
Hypertonic
(Less Water)
A comparative term used to describe one of two solutions. Has higher concentration of dissolved material than the other solution.
(Less Water)
Hypotonic
(More Water)
One of two solutions having a lower concentration of dissolved materials.
(More Water)
Isotonic
(Equal Water)
Two solutions that are equal in dissolved materials.
(Equal Water)
Facilitated Diffusion
The diffusion of molecules through the transport proteins. Follows Concentration Gradient.
Diffusion, Osmosis, and Facilitated Diffusion are forms of ______________.
Passive Transport
Passive Transport
Does NOT require energy input from the cell.
Active Transport
The process of moving molecules through a protein molecule in the lipid bilayer from low to high area of concentration.
In Active Transport the protein is activated ___________________.
by an energy boost from ATP, provided by the cell.
Exocytosis
Movement of molecules out of the cell by means of a transport vesicle. Vesicle membrane fuses with plasma membrane so that vesicle contents are released. (EX=EXIT)
Endocytosis
The movement of materials into the cell. The material becomes enclosed by a patch of plasma membrane and then sinks into the cytoplasm and forms a vesicle around it. (EN=ENTER)
Phagocytosis
“Cellular Eating” Engulfment of foreign materials by means of Endocytosis. Forms food vesicles. Used by Amoebas and WBC.
Pinocytosis
“Cellular Drinking” The Endocytosis of liquids. Occures on a smaller scale than phagocytosis and form vesicles containing the liquid.
Receptor-Mediated Endocytosis
Proteins with specific receptor sites are embedded in the membrane of a cell. When the right molecule binds with the receptor it triggers the endocytosis of the molecule.
