Across
- 4. the passive movement of molecules or ions across a membrane with the help of specific transport proteins. It does not require energy. (2 words no space between the words)
- 5. the rapid side-to-side movement of phospholipids and proteins within the same layer of the membrane.
- 7. the process by which a cell secretes molecules by fusing a vesicle with the plasma membrane, releasing its contents to the outside.
- 14. the property of a membrane that allows some substances to pass through more easily than others, while blocking the passage of certain molecules. 2 words no space between the words)
- 15. are lipids with covalently attached carbohydrates.
- 16. a model that describes the structure of the plasma membrane as an assortment of various proteins embedded in a phospholipid bilayer.
- 17. Transport proteins that bind to specific molecules, undergo a conformational change, and then release the molecule on the other side of the membrane. (2 words no space between the words)
- 20. a cell placed in a ________________________ solution will gain water and swell.
- 21. fatty acids have straight tails that can pack together more closely, making the membrane more viscous and less fluid.
- 24. proteins that have both hydrophilic (water-loving) and hydrophobic (water-fearing) parts.
- 25. a type of endocytosis where a cell engulfs large particles, such as bacteria or debris, by extending pseudopods around them to form a vesicle. (2 words no space between the words)
- 26. fatty acids have double bonds that cause kinks in their tails, preventing them from packing tightly and increasing membrane fluidity.
Down
- 1. the spontaneous movement of a substance from a region of high concentration to a region of low concentration.
- 2. The combined effect of an ion's concentration gradient and its electrical gradient across a membrane. (2 words no space between the words)
- 3. the process by which a cell takes in molecules and other substances by forming new vesicles from the plasma membrane. (2 words no space between the words)
- 6. this molecule has hydrophilic heads that face the aqueous environment, and hydrophobic tails are tucked in the interior, away from water.
- 8. Transport proteins that form a pore through which specific ions can pass. They can be gated, opening or closing in response to certain stimuli. (2 words no space between the words)
- 9. is a type of steroid lipid found in animal cell membranes. It acts as a "fluidity buffer" by making the membrane less fluid at warmer temperatures (by restricting phospholipid movement) and preventing it from becoming too solid at colder temperatures (by preventing tight packing).
- 10. The two sides of a cell membrane, the inner and outer leaflets, have different lipid and protein compositions. This is called what? (2 words no space between the words)
- 11. a cell in an ________________________ solution will not experience a net movement of water.
- 12. a highly specific type of endocytosis where a cell takes in specific molecules by binding them to receptors on the cell surface, which then cluster and are internalized in a vesicle. (3 words no space between the words)
- 13. proteins with covalently attached carbohydrates
- 18. proteins that span the membrane and provide a passageway for specific molecules or ions to cross.
- 19. The movement of substances across a membrane against their concentration gradient (from low to high concentration), which requires energy (usually from ATP). (2 words no space between the words)
- 22. the diffusion of water across a selectively permeable membrane from an area of high water concentration to an area of low water concentration.
- 23. a solution with a higher concentration of solutes compared to another solution.