Cell Biology Flashcards
hypertonic solution
- concentration of H2O is greater in cytoplasm than in the solution
- concentration gradient exists (H2O is in [HIGH] in cytoplasm than in solution)
- net movement of H2O molecules from cytoplasm into solution
- cell shrinks and dies
chromatin: structure & function
function
- contains DNA which has the instructions to control cell activities
- scattered through nucleus in a non dividing cell
structure
- coiled DNA: turned off and cannot make mRNA
- uncoiled DNA: turned on and can make mRNA
cilia
- act in unison to move substances across cell surface in one direction
- extensions of the cell membrane to the exterior
- 9+2 arrangement of microtubules
microvilli
- increase the membrane surface area for absorption purposes
- projections of the cell membrane
nuclear membrane
- semipermeable; selects what enters and exits the nucleus
- encloses nuclear content; a double membrane with pores
rough er
- where proteins produced by its ribosomes enters subway system; transports proteins to smooth er
- throughout cytoplasm
smooth er
- area of subway system where compounds likes proteins leave the er in a membrane bound sac
- produces phospholipids
- in cytoplasm near golgi
cytoskeleton
- support and suspend structures of the cell
- microtubules and microfillaments
active transport
- active transport mechanism
- needs carrier protein
- ATP required
- [LOW]->[HIGH]
- sodium potassium pump
phagocytosis
- cell engulfs a substance within a membrane bound sac
- ATP required
osmosis
- no ATP required
- H2O goes through [HIGH WATER]->[LOW WATER] through semipermeable membrane
exocytosis
- ATP required
- membrane bound vesicle attaches to to the plasma membrane and releases its contents to the exterior
- vesicle membrane becomes part of plasma membrane
ATP
-produced when covalent bonds of glucose are broken and the energy released is stored in the high energy bond of ATP
equilibrium
-no net diffusion
cellular respiration
C6H12O6 + 6O2 -> 6CO2 + 6H2O + 36 ATP
photosynthesis
6CO2 + 6H2O -> C6H12O6 + 6O2
ATP - mitochondria
- controls release of energy from foods
- forms atp through cellular respiration
cell membrane
- external boundary of the cell
- confines cell contents; regulates what goes into and out of cell (semipermeable)
hypotonic solution
- concentration of salt/solute and H2O are not equal on either side of cell membrane
- H2O is in [HIGH] outside the cell and [LOW] within cell
- net movement of H2O molecules into cell
- cell swells and explodes
nucleolus
- dark spherical area within nucleus
- assembly area for ribosomes
receptor proteins
- specific site that allows a specific molecule to bind to it
- chemical messenger of hormone must fit receptor site in order to affect the metabolism of the target cell
sodium potassium pump
- specific carrier protein that is present in neuron cell membranes
- transports 3 sodium ions from the neurons cytoplasm into surrounding interstitial fluid
- 2 potassium ions from the interstitial fluid into the neurons cytoplasm
nucleus
- usually in centre shaped in an oval or circle
- stores genetic info in the form of genes in DNA
- directs cellular activities
fluid mosaic
-based on the changing location (fluid) and pattern of proteins (mosaic) in the phospholipid bilayer
facilitated diffusion
- requires transport protein to move substances faster than normal diffusion
- O2 transport to blood
- [HIGH]->[LOW]
- no ATP required
lysosomes
- scattered throughout cytoplasm
- contains digestive enzymes that break down ingested materials within cell
- also break down worn out organelles
Golgi apparatus
- in cytoplasm near nucleus
- forms membrane bound sac - lysosomes
- also form membrane bound sacs called secretory vesicles
centrioles
- two rod shaped bodies near nucleus
- may be involved with production of spindle fibres that pull apart sister chromatids of each chromosome
ribosomes
- attaches to rough er or scattered into the cytoplasm
- synthesize proteins (enzymes, hormones, structural proteins)
vesicles or vacuoles
- throughout cytoplasm
- transports or stores nutrients, cell waste products, hormones, proteins like hormones and enzymes, etc
peroxisomes
- throughout cytoplasm; a membrane bound sac
- detoxifies alcohol and free radicals that accumulate from normal metabolism in liver
cell wall
- surrounds cell membrane in plant cells (cellulose)
- permeable: allows particles to move freely in either direction; support
chloroplasts
- cytoplasm of plant cells and green algae
- photosynthesis: using solar energy
- H2O and CO2 react to form organic compounds and O2
inter-relationship between Golgi apparatus, etc and secretion
- gene in DNA (nucleus) makes mRNA
- mRNA goes through nuclear pore to cytoplasm
- rough er (ribosomes of rough er)
- polypeptide; must take specific shape to become a functional protein
- enters rough er
- transported to smooth er
- transport vesicle
- golgi apparatus
- lysosomes (hydrolytic enzymes) and transport/secretory vesicle-> contents of vesicle leaves by exocytosis
