Chapter I and II Flashcards
unspecialised animal cells have
- cell membrane
- cytoplasm
- mitochondria
unspecialised plant cells
- a cellulose cell wall
- a permanent vacuole
- chloroplasts (green parts of the cell)
→ chlorophyll for photosynthesis
cells
- all living organisms are based on units known as cells
-most cells share basic features, but the size, shape & specialised features of the cells are tied to their function
organisation levels for nuclear organisms
- organ systems
- organ
- tissue
- cell
- organelles
- molecules
- atoms
organ systems
group of organs working together to perform body functions e.g. digestive system
organ
group of tissues working together to perform a specific function
tissue
group of cells working together (cell same structure)
cell
structural and functional unit of all living organisms
organelles
cell structure having a specific function within the cell
molecules
group of atoms bonded together
atoms
smallest component of an element
movement in and out of cells
- cell membrane shows selective permeability*
- whether a molecule can pass through the cell membrane depends on its SIZE and its ELECTRICAL NATURE
*the ability of a substance to allow gases or liquids to go through it
the phospholipid bilayer is
- highly permeable to small non polar (hydrophobic) molecules like O2, CO2, small lipids
- slightly permeable to small polar molecules like H20
-not permeable to large polar molecules like glucose and ions (charged atoms and molecules)
diffusion
– spontaneous random movements
– (kinetic energy)
– no energy needed
– particles move from a high concentrated region to a less concentrated region
osmosis
osmosis is the diffusion of solvent/water molecules across a partially permeable membrane from a lower to higher solute concentration (→up the solute gradient)
FFFFFfacilitated diffusion
→diffusion of a molecule through a specific transport protein
- channel protein
- carrier protein
active transport
transport of a molecule against the concentration gradient through specific proteins (carriers) requiring energy
macromolecules
a molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer.
macromolecules pass the membrane through endo- and exocytosis
→ mecanism of active transport which allows the enty or exit of big particles & macromolecules