Chapter 2 - Membranes and Cell Organelles Flashcards
apoptosis
programmed cell death
self destruction by cells for the good of the whole organism
eukaryotic cells
contain membrane bound organelles
larger
found in animals, plants, fungi
cytoskeleton
prokaryotic cells
lack membrane bound organelles no nuclear membrane no true nucleus unicellular smaller bacteria
basic cell processes
obtain nutrients synthesis materials for growth and repair energy for movement and metabolism eliminate waste carry out cell division
factors that affect cellular activity
composition of extracellular fluid salt concentration temperature nutrients levels pH removal of wastes
plasma membrane / Fluid Mosaic Model
partially permeable boundary of all living cells which acts as a barrier between the internal and external environment and controls the entry of dissolved substances into and out of the cell
partially / selectively permeable
allows only some substances through but not others
structures within the plasma membrane
proteins and glycolipids protrude
embedded protein channels
types of proteins in plasma membrane
transport proteins
receptor proteins
glycoproteins
adhesion proteins
transport proteins
allows some substances to move through the membrane
channel and carrier proteins
receptor proteins
binding sites
hormones and other substances bind to them affecting the cells activities
glycoproteins
act as antigens which enable the immune system to recognise self from non-self cells
adhesion proteins
join cells together in multicellular organisms
diffusion
the net movement of a molecule or ion from a region of high concentration to a region of low concentration
passive
along concentration gradient
stops at equilibrium
facilitated diffusion
type of diffusion where charged particles (ions) and larger particles (glucose) diffuse across a membrane with assistance from transport proteins
along concentration gradient
passive
channel proteins
channels which open and close to allow molecules nd ions through
carrier proteins
combine with the molecule or ion and carry it across the membrane
osmosis
the net movement of water from a weak or dilute solution to a strong or concentrated solution
along concentration gradient
passive
hypotonic
dilute solution with high concentration of solvent (H2O) and low concentration of solute
hypertonic
concentrated solution with a low concentration of solvent (H2O) and a high concentration of solute
isotonic
surrounding fluid is equal concentration to the solution inside the cell
no net movement of water
turgid
external concentration hypotonic to the vacuole
water will move freely into the vacuole via osmosis
vacuole swells and pushes the plasma membrane against the cell well creating turgor pressure
flaccid
external concentration hypertonic to the vacuole
water will move freely out of the vacuole via osmosis
vacuole size reduced and moves the plasma membrane away from the cell well create limp cell
active transport
the movement of molecules or ions from a region of low concentration to a region of high concentration
against concentration gradient
active
involves carrier proteins
endocytosis
the process of bulk transport of material into a cell
requires energy
pinocytosis and phagocytosis
pinocytosis
bulk movement of smaller particles (liquids) into cells
phagocytosis
bulk movement of larger particles (solid material) into cells
exocytosis
bulk transport of material out of cells
requires energy
in small vesicles from golgi
factors affecting movement of materials
concentration gradient
surface area to volume ratio
Golgi
Packages material into vesicles for export
