English scientist Robert Hooke created a microscope and saw "little boxes" in a slide of cork which he called cells. (1665)
Anton van Leeuwenhoek Dutch scientist used a microscope and discovered living creatures in a pond water. He called them animalcules, they were single-celled organisms. (1675)
Matthias Schleiden, concluded that every part of the plant was made of cells (1838)
Theodor Schwann, zoologist concluded that animals were made up of cells (1839)
Rudolph Virchow, physician said cells come only from existing cells.
They created the cell theory:
All living things are made up of one or more cells
Cells are the basic unit of structure and function in organisms
All cells arise from existing cells
Cell's shape vary, depending on it's function.
Cells may grow in one or two dimensions but remains smaller in others.
The smaller the cell is more efficiently, nutrients and waste travel faster.
All cells have a membrane, cytoplasm, ribosomes and DNA.
DNA provides instructions to make proteins, regulates cellular activities, enables cells to reproduce.
Prokaryotes are single-celled organisms that lack of nucleus and membrane-bound organelles
Organelles: structure that carries specific function inside the cell.
Prokaryotes may have lived 3.5 billions ago, they were the only organisms on earth for million of years ago.
Eukaryotes: organisms made up of one or more cells that have a nucleus and membrane-bound organelles.
Because of their complex organization, eukaryotes carry out more specialized functions than prokaryotic cells.
DNA is in a nucleus, unlike prokaryotes that lies in the middle.
Cytoskeleton web of protein fiber that provides shape and structure, it helps the cell move and organize it's parts.
Microfilaments: act like muscles, they contract to pull the membrane and expand to push in others.
Microtubules: tubes where molecule information pass through
Intermediate fibers: anchor organelles and enzymes to certain...