Cell theory Flashcards
all organisms are composed of
one or more cells
are the smallest and basic units of structure and function in organisms
cell
cell arise only from
previously existing cells
organisms are either
prokarykotic or eukaryotic cells
a gel-like substance making up the cells internal
environment and where organelles are suspended in microscopic fibers called—-
Cytoplasm, cytoskeleton
an outer boundary that regulates the passage of materials into and out of the cell
cell membrane / plasma membrane
what are the two main types of cells
prokaryotes and eukaryotes
it is the first cell to develop about 3.8 billion years ago
prokaryotes
a central genetic region containing the genetic material in the form of DNA that provides instructions to make proteins, regulates activities and enables cells to reproduce
nucleus
simple organisms possessing cells that are smaller in size with simple internal structures
prokaryotes
life forms such as bacteria, algae and archeans
prokaryotes
a larger size and more complex structural components that was found 1.8 billion years ago
eukaryotes
have genetic material (DNA) encased within a distinct nucleus
eukaryotes
higher form of organisms such as fungi, plants, animals and protist
eukaryotes
a living system that controls the passage of needed materials into and out of the cell
cell membrane / plasma membrane
a thin barrier that forms a boundary separating an individual cell from an external environment
cell membrane / plasma membrane
have many membrane-bound interior compartments and their organelles are neatly arranged
eukaryotes
molecules help strengthen the cell membrane, making it more flexible but less fluid, which makes the membrane less permeable to water-soluble substances such as ions or simple sugars
cholesterol
attached to membrane proteins serves as identification tags, enabling cells to distinguish one type of cell from another
carbohydrates
a type of membrane protein
extend from the phospholipid layer to help materials cross the membrane
transport proteins
form tunnels that helps cells to import or export needed materials and expel wastes
channel proteins
enables cells to distinguish own cells from that of other organisms such as pathogens that may invade the body
cell recognition proteins
participate in metabolic reactions such as degradative and synthetic reactions
enzymatic proteins
act as a muscle and skeleton to maintain cell shape and motility
cytoskeleton proteins
assist cell to cell adhesion and communication between cells
junction proteins
facilitate exchange of signals with other cells by changing shape to allow a specific molecule, the ligand, to bind to it
receptors proteins
an additional boundary for plants, algae, fungi, and some bacteria
cell wall
first to be credited in publishing of seeing a cell in 1666
robert hooke (1635-1703)
his drawings were collected in a manuscript called—-
robert hooke (1635-1703), micrographia
a dutch naturalist, credited to be the first to study magnified cells
antonie van leeuwenhoek(1632-1723)
first invention was a simple microscope with only one lens
antonie van leeuwenhoek(1632-1723)
most commemorative work came from a thin slice of cork from a bark of an oak tree
robert hooke (1635-1703)
german botanist, focused on the study of plant cells
Mathias Jakob Schleiden (1804-1881)
he did not use the word cells and referred them as “animalcules”
he was the first to observe living cells
antonie van leeuwenhoek(1632-1723)
german physiologist, examined animal cells
Theodor Schwann (1810-1862)
german physician,
proposed a third tenet in the cell theory,
he states that all cells come from other cells through the process of cell division
Rudolf Carl Virchow
