Types of Microscopes and their function
Compound Light Microscope–light shines through specimen on a glass slide
Electron Microscope–used to view dead specimens
Transmission Electron Microscope–electron beam is directed at a very ting slice of the specimen stained with metal ions
Scanning Electron Microscope–electron beam is focused on a specimen coated with a very thin layer of metal
Scanning Tunneling Microscope–uses needle-like probe to measure differences in voltage caused by electrons that tunnel from the surface of the specimen
Cells
Cell Theory–proposed by Schleiden, Schwann, and Virchow
1) All living things are made of one or more cells.
2) Cell is the basic units of structure and function in living organisms.
3) All cells arise from preexisting cells.
Prokaryote Cells
ex: bacteria and archeabacteria
Single cell
Lack nucleus and other membrane-bound organelles
DNA is free-floating in the cytoplasm
No cytoskeleton
Cell Wall
Capsule (usually)
Flagella/Cilia for movement
Eukaryote Cells
ex: plant and animal cells
Single or multi-cellular
Contains nucleus and membrane bound organelles
plant cells contain cell wall, animal cells do not
Flagella/cilia for movement
Cell Organelles
Nucleus–directs cell activities and stores DNA
Cell Membrane–barrier–allows certain things in and out of the cell
cytoskeleton–provides support for the cell
mitochondria-power house of the cell–energy is made here (ATP)
Lysosome–digestion/breakdown of old cell parts, carbohydrates, proteins, lipids, foreign invaders
Golgi apparatus–modifies, packages and distributes proteins throughout the cell
ribosomes–site of protein synthesis
vesicle–small sac that transports materials throughout the cell
Rough Endoplasmic Reticulum (ER)–covered in ribosomes, accepts proteins from ribosomes and packs the proteins then sends to Golgi Apparatus
Smooth ER–no ribosomes–makes lipids and breaks down toxic substances
Unique to Plant Cells
Cell Wall–provides support, protection, and maintains the shape of the cell
Chloroplasts–use light energy to make food (glucose) for the plant
Central Vacuole–stores water and other substances–helps cell keep its rigid shape
Passive Transport
-requires no energy
-works by going with the concentration gradient–from high concentration to low concentration
Types of passive transport–diffusion–osmosis–facilitated diffusion–ion channel
Active Transport
-requires energy to move the materials across the cell membrane
-substances are moved against their concentration gradient–from low to high concentration
Types of active transport–ion pump, exocytosis, endocytosis, membrane receptor proteins
