1 / 5

Ch 3, Sec 4 The Cell in Its Environment

Ch 3, Sec 4 The Cell in Its Environment Target: Understand how most small molecules cross the cell membrane, why osmosis is important to cells, the difference between passive & active transport Selectively Permeable (like a strainer)

zihna
Download Presentation

Ch 3, Sec 4 The Cell in Its Environment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ch 3, Sec 4 The Cell in Its Environment Target: Understand how most small molecules cross the cell membrane, why osmosis is important to cells, the difference between passive & active transport Selectively Permeable (like a strainer) - some substances can pass through the membrane while others can’t - needed materials, such as food molecules & oxygen, and waste materials must be allowed to go in & out of cell membrane

  2. Diffusion (particles) - process by which molecules move from an area of higher concentration to an area of lower concentration - main method small molecules move across cell membrane - molecules are constantly moving, the more concentration of molecules, the more they bump into each other, and push away from each other, eventually spread out evenly

  3. Osmosis (water) - diffusion of water molecules through selectively permeable membrane (still moves from higher concentration to lower) - water passes easily through cell membrane - cells cannot function properly without adequate water, many cell processes depend on osmosis Effects of Osmosis on cells - if a cell is in a low salt solution (hypotonic), cell will explode - if a cell is in a high salt solution (hypertonic), cell will shrink

  4. Passive Transport - movement of dissolved material through cell membrane with no cell energy used - osmosis & diffusion both passive transports Active Transport - movement of substance in opposite direction; going from lower concentration to higher - requires cell energy Transport Proteins (like a tunnel) - how calcium, potassium, & sodium are carried in & out of cell - requires cell energy, form of active transport

  5. Engulfing - type of transport, requires energy - cell membrane surrounds a particle and engulfs it - uses cell energy - how cells eat & drink (endocytosis & pinocytosis) Why Cells stay Small and don’t get too big - as a cell gets bigger, it takes longer for molecules to move throughout it. Can’t keep up with demand of growth, so cell divides to keep up with demand but not over tax the cell

More Related