Biology Assignment 8: Plasma Membrane
a molecule that has partial positive and negative charges at each end
polar molecule
movement of particles or molecules from higher concentration to lower concentration
diffusion
when cells engulf or ingest substances
endocytosis
when cells expel or get rid of substances from within
exocytosis
a solution with the same salt concentration as the salt concentration inside the cells
isotonic
the diffusion of water across a semipermeable membrane
osmosis
cell engulfs molecules in cell "drinking":
pinocytosis
when cells eat small or dissolved substances
pinocytosis
molecules "pumped" in or out from low to high concentration:
active transport
This transportation process requires the cell to move particles from low concentration to high concentration.
active transport
chemical reactions in plants and animals that break down food molecules into energy (ATP)
cellular respiration
transports glucose, amino acids
facilitated diffusion
transports sodium, potassium
active transport
the high energy chemical compound with three phosphate groups that provides energy for all other cell activities
adenosine triphosphate
Movement of any particle or molecule from higher concentration to lower concentration is called _____.
diffusion
The natural tendency of molecules to move from higher to lower concentrations is____
diffusion
molecules move in and out freely from high to low concentration:
diffusion
molecules helped by protein; move insoluble molecules across plasma membrane:
facilitated diffusion
A plasma membrane and a cell wall _____.
have different structures and different functions
the relatively constant state in the internal environment of an organism
homeostasis
a solution that has a higher salt concentration than the salt
hypertonic
a solution that has a lower salt concentration than the salt concentration inside the cells
hypotonic
Diffusion of water across a membrane from areas of higher concentration to areas of lower concentration is called _____.
osmosis
oxygen, carbon dioxide
passive diffusion
when cells eat other cells or large substances
phagocytosis
a molecule with polar and nonpolar ends that, along with protein, makes up the plasma membrane
phospholipid
What molecule forms the cell membrane?
phospholipids
When is facilitated diffusion necessary?
when molecule is insoluable
Which statements correspond to cellular respiration?
CO2 diffuses passively out of the cell. O2 diffuses passively when converted to CO2.
Why do O2 and CO2 pass through the plasma membrane?
they are nonpolar and soluable
The outer layer of a cell that acts as a gatekeeper to a cell is the _____.
plasma membrane
a large, complex organic molecule consisting of a large number of amino acids linked together by peptide bonds
protein
Glucose will pass through a cell membrane with the aid of .
proteins
The plasma membrane has a double layer of phospholipids with _____ dispersed throughout.
proteins
