Chapter 3 Flashcards
Human cells have three basic parts
plasma membrane, cytoplasm, nucleus
Plasma membrane
flexible outer boundary
Cytoplasm
intracellular fluid containing organelles
Nucleus
DNA containing control center
Lipid bilayer is made up of
75% phospholipids
Two parts of phospholipids
phosphate heads and fatty acid tails
Phosphate heads
polar and hydrophilic
Fatty acids tails
non polar and hydrophobic
Integral proteins
firmly inserted into membrane
Integral protein function
transport proteins, enzymes, or receptors
Peripheral proteins
loosely attached to integral proteins
Peripheral proteins function
enzymes, motor proteins for shape change during cell division and muscle contraction, cell-to-cell connections
Glycocalyx function
specific biological markers for cell-to-cell recognition
allows immune system to recognize “self” vs. “non self”
Tight Junctions
integral proteins on adjacent cells fuse to form an impermeable junction that encircles whole cell
Desmosomes
rivet-like cell junction formed when linker proteins of neighboring cells interlock like the teeth of a zipper
Gap Junctions
transmembrane proteins form tunnels that allow small molecules to pass from cell to cell
Passive Tranport
energy or no?
no energy
Types of passive transport
diffusion and filtration
Diffusion
movement of molecules down their concentration gradients (from high to low)
Hydrostatic pressure
pressure of water inside cell pushing on membrane
Osmotic pressure
tendency of water to move into cell by osmosis
Isotonic solution
same osmolarity as inside the cell, so volume remains unchanged
Hypertonic solution
higher osmolarity than inside the cell, so water flows out of cell, resulting in cell shrinking
Hypotonic solution
lower osmolarity than inside cell, so water flows into cell, resulting in cell swelling
Shrinking is referred to as
crenation
Cell bursting is referred to as
lysing
Active Transport
moves solutes against their concentration gradient (from low to high)
-required energy (ATP)
Endocytosis
involves formation of protein-coated vesicles
Phagocytosis
type of endocytosis that is referred to as “cell eating”
Who is phagocytosis used by?
macrophages and certain other white blood cells
Pinocytosis
type of endocytosis that is referred to as “cell drinking” or fluid-phase endocytosis
Receptor-mediated endocytosis
involves endocytosis and transcytosis of specific molecules
