Chapter 3 Cellular Level Of Organization Flashcards
Cell theory
- all living organisms are made of cells
- all cells come from previously existing cells
History of Cells
1600’s Cell discovered and named by Robert Hooke
- 1800’s Scheiden- all plants made of cells
- Schwann-all animals made of cells
Cells
Smallest unit of life on our planet (unicellular or multicellular life)
-small so that they have a large surface area to volume ratio, allows diffusion to move molecules
Prokaryotic cells
No membrane-bounded nucleus
Eukaryotic
Have a membrane-bounded nucleus
Cell made up of three parts
Plasma membrane- separates inside of the cell from outside, determines what enters or leaves
- nucleus: large structure in the cell that houses genetic material DNA
- cytoplasm: 2 subparts cytosol (fluid) and organelles (structures in fluid)
Plasma membrane structure
Phospholipid bilayer that separates cell from interstitial fluid
- fluid mosaic model=thick potato soup
- selectively permeable: determines what crosses in or out, nonpolar can, polar cant
Passive transport
Diffusion moves through membrane the down conc. gradient, no energy needed
Facilitated diffusion
diffusion occurs using a carrier
Osmosis
diffusion of water from its high concentration to its low
Osmotic Pressure
gradient of water trying to diffuse
Tonicity
measure of a solution’s ability to affect the water content of cell
Hypotonic
solution is less concentrated than cell, water moves into cell from solution, blows up cell
Hypertonic
solution more concentrated than cell, water moves from cell to solution, cell shrinks
Isotonic
solution of same concentration as cell, water net movement is zero
Active Transport
requires energy to move chemical against its concentration gradient
Endocytosis
inward movement of substance
Antiporters
Na+ and substance move opposite direction
Symporters
Na+ and substance move same direction
Exocytosis
outward movement of substance
