Cell biology; Biology part 1

-all living things are made of cells

-cells contain all the basic units needed for life

-all cells come from other cells

-cells are small and tend to maximize their surface area

as cell size increases, the surface area to volume ratio decreases

-thus rates of chemical exchange may then be inadequate for cell size.

refract visible light passing through a specimen such that projected image is magnified

focuses a beam of electrons through the specimen

Transmission electron and scanning electron

electron beam scans the surface of specimen.

-image appears 3-D

a beam of electrons passed through a thin section of specimen stained with atoms of heavy metals and electromagnets

-in nuceoid region

-usually smaller

-usually single-cell

-may not need oxygen

- no membrane-bound organelles

-within membrane bound nucleus

-usually larger

-often multicellular

-usually need oxygen to exist

-membrane-bound organelles

-complex, dynamic structures made of lipid and proteing molecules

• *communicates with other cells
• *regulates passage of materials
• *transmits signals between cell interior and the environment

know parts!!

-Passive transport

-active transport

-Exocytosis

-Endocytosis

-diffusion and Osmosis

-channel proteins and carrier proteins

movement of molecules out of cell using membrane fusion

ex)removing cellular waste; exporting proteins

movement of molecules into the cell using membrane fusion

net movement of a substance from a region of greater to lower concentration

net water movement into the cell

net water movement out of water

no net water movement