| A | B |
|---|
| active transport | passage of a substance across a semi-permeable membrane requiring use of energy (chemical) |
| ions or molecules are moved ___________ | against concentration gradient - low to high |
| carrier proteins | cell membrane pumps - moves substances up their concentration gradients |
| an example of carrier proteins is when sodium/potassium pum _______ | mechanism that moves NA+ out of the cell and forces K+ in |
| carrier protein process depends on __________ | ability of carrier to change shape - 3 sodium ions fit into carrier molecule |
| chemical reaction using ATP - changes shape of the carrier and __________ | causes sodium to be released outside cell |
| carrier has shape needed to _______ | accept two K+ ions |
| loss of a phosphate from ATP causes __________ | shape change and releases K+ inside cell |
| In carrier protein section, this change causes build up of ___________ | positive charge outside cell and creates a gradient of electrical charge across membrane |
| in the carrier protein section: nerve impulses and __________ | muscle contraction |
| endocytosis and exocytosis | allow large molecules and large quantities of small molecules to enter and leave cell without passing through membrane |
| endocytosis and exocytosis allows: ___________ | maintaining balance, bringing in foods, exporting proteins and excreting wastes |
| endocytosis | engulf substances bringing them into cell |
| materials in endocytosis are __________ | enclosed by a part of cell and forms a pouch - vesicle |
| in endocytosis, it pinches off ___________ | from membrane and enters cytoplasm |
| in endocytosis....you wrote: digested by __________ | enzymes |
| two kinds of endocytosis (based on materials enclosed): ________ | pinocytosis and phagocytosis |
| pinocytosis | movement of solutes or fluids |
| phagocytosis | movement of large food particles or whole cells (amoebas feed) |
| mammals (WBC) phagocytes ___________ | engulf and digest bacteria (lysomes fuse with vesciles) |
| exocytosis | vesciles fuse with cell membrane and release contents to the outside |
| example of exocytosis | proteins |
