Cells
What is the cell theory?
- all organisms are composed of cell and cell products
- all cells come from previously existing cells
What is the function of the plasma membrane?
- separates living cell from nonliving surroundings
- thin/flexible layer that separates intracellular/inside from extracellular/outside
What is diffusion? What is osmosis? What is facilitated diffusion? These are all kinds of what?
- diffusion: movement of particles from high to low concentration, until we reach equilibrium
- osmosis: transport of water across selective permeable membrane
- facilitated diffusion - transport via specific transport proteins that act as selective corridors
- all kinds of passive transports - no ATP/energy required
What are the organic molecules? Are they alive?
- proteins, carbohydrates, lipids, nucleic acids
- they are NOT alive
What are the 3 main parts of a cell?
- plasma membrane
- cytoplasm
- nucleus
What forms the plasma membrane?
- phospholipids form the phospholipid bilayer
- tail of 2 fatty acid chains → nonpolar/hydrophobic
- head of phosophate group → polar/hydrophilic
- proteins embedded into bilayer → make up 50%
Who was Robert Hooke?
- "father of microscopy"
- coined term "cell" to describe basic unit of life
How many distinct cell types make up the human body?
210
- membrane phospholipids and proteins can drift in plane of membrane
- "fluid" - molecules can move freely within membrane
- "mosaic" - diversity of proteins exists within membrane
- glycolipids - on surface, 10%
- cholesterol - inside/nonpolar, 5-20%
- carbohydrates - the rest
We come from an initial cell. What is it called?
- zygote
- single-celled
- formed by fertilization
How do cells differ from one another?
- morphology - physical appearance (structure, size, shape)
- ability to move
- internal organization (prokaryotic vs eurkaryotic)
- metabolic activities
What are integral membrane proteins? What are peripheral membrane proteins?
- integral: transmembrane, span width of entire membrane, contain hydrophobic and hydrophilic regions, integrated inside membrane
- peripheral: do not span entire membrane, loosely associated with other proteins or lipid molecules, on the surface
List the Hierarchy of Life from smallest to largest.
atom → molecule → cell → tissue → organ → organ system → organism → population → community → ecosystem
Name all the functions of the membrane proteins. What is the main function?
- attachment to cytoskeleton and extracellular matrix - cells join together to form tissues
- cell signaling - proteins cause cell reactions
- enzymatic activity
- transport - allow for things to pass through plasma membrane into cell
- intracellular joining
- cell-cell recognition
- main function - selective permeability: allow some substances to cross more easily than others