Kaylee
Cell Membrane/Cell Theory
Early studies led to the development of the cell theory. In 1665, Robert Hooke used a three-lens microscope to examine a cork. The cork is made of tiny, hollow compartments. These compartments reminded him of small rooms, so he called them cells. Anton van Leeuwenhoek's single- tensed, microscope was more powerful than Hooke's compound microscope.
The Cell Theory consist of that all living things are made up of cells. The new cells are produced by other living cells. And that the cell is the most basic unit of life. Prokaryotic cells lack a nucleus and most internal structures of eukaryotic cells. Cells are enclosed by a cell membrane that controls the movement of materials into and out of the cells. There are two different types of cells. Firstly, is prokaryotic cells they do not have a nucleus or other membrane- bound organelles. The cell's DNA is located in the cytoplasm. Most are microscopes, single-celled organisms. Next Eukaryotic cells do have a nucleus and other membrane- bound organelles. The nucleus also has the largest organelle, encloses genetic information. May be multicellular or single-celled and the cytoplasm is a jelly like cell.
This is Robert Hooke and picturede the miscrscope he used to discover cells.
Cell Membrane
Different types of protein are embedded in the lipid bilayer. These proteins can float among the lipids. Some proteins extend all the way through the lipid bilayer and form channels and pumps. Carbohydrates ate molecules are attached to many of these proteins. They extend beyond the cell membrane and outside the the cell into its surroundings.
Purpose
The cell membrane regulates the movement of materials in and out of the cell. If it didn't, it would be unable to maintain homeostasis.
The cell membranes lipids molecules have two hydrophobic "traits" that are "water- fearing" - they are repelled by water. They also have hydrophilic "head" that is "water-leaving" - it is attracted to water.
A lipid bilayer is a flexible double- layered sheet that makes up the cell membrane and forms a barrier between the cell and its surroundings.
The Fluid Mosaic Model
Biologist have developed a conceptual model of what the cell membrane looks like.
The Fluid-Mosaic model describes the cell membrane with a lipid bilayer in which protein and other molecules are embedded. The cell membranes selectively permeable. Selectively permeable is a property that allows some substances to enter through a membrane but hot others. Selective permeability helps a cell maintain homeostasis.