4-5.9 test notes Flashcards
(45 cards)
high surface area to volume ratio makes
efficient cells
to calculate surface area of a cube you
Length x Width x 6 mm ^2 (squared)
to calculate volume of a cube
Length x Width x Height mm ^3 (cubed)
Cells with odd shapes
have greater surface area to volume ratio
semi/selectively permeable, plasma membrane all mean?
cell membrane
The cell membrane helps
communicate with other cells, creates attachments between cells and protects the cell
is used for transport and maintaining homeostasis
thin, liquid bilayer , that is semi-permeable, regulates movement on materials, entering and exiting the cell
Exocytosis
move stuff out —> vesicle fuses with membrane
typically the secretion of larger molecules
Endocytosis
bring in —> take in macromolecules by forming vesicle around it
Phospholipid bilayer
allows flexibility, prevents water from flooding, allows small non polar molecules through easily (ex. oxygen and co2)
Pinocytosis
cell drinking fluid
non-specific
Phagocytosis
cell eats
targets large structures + not particularly specific
Passive transport
Requires no energy
Movement from a high concentration to a low concentration
Diffusion
particles moving from a high to low concentration
ex. air freshener and perfume 
diffusion across the membrane is too slow
equilibrium
particle/molecules are equal on both sides of the membrane
osmosis 
movement of water from HC to LC across the cell membrane 
isotonic 
equal, both moving in and out 
hypertonic 
solution is greater on the outside water moves out (shrinks)
hypotonic 
solution is greater inside water moves in (bursts) 
turgor pressure 
cell wall sustains shape, otherwise would explode 
Aqua Porins 
Channel proteins, that help transport water across the membrane —> necessary bc water is polar! 
Active transport 
moving from LC to HC —> requires energy 
sodium potassium pump helps
keep ions in place, making a concentration gradient low —> high
Cell theory (3)
- all living things are composed of cells
- cells are the basic unit of structure and function for living things
- All cells come from pre-existing cells 
how do organisms grow
by adding on more cells NOT by increasing the size of their cells