Named cells after viewing dead empty cork cells- reminded him of monk rooms, also called cells.
The work of these individuals and others were combined into this theory. 1. cells are the basic units of structure and function in all organisms. 2. all organisms are composed of 1 or more cells. 3. Cells come from pre-existing cells through cell division
Principle that says that cells come from preexisting cells through the orderly process of cell division.
Cells average from 10-50 microns in diameter, they are limited to this size due to their surface area to volume ratio
The cells amount of cell membrane. cells obtain all their needs by absorbing them across their cell membrane
Cells Increase in Size
a cells amount of cell membrane (their surface area) increases by the square but their volume increases by the cube. with increased volume the cell has a greater demand for food, oxygen, and produces more waste but its cell membrane (surface area) its to small to handle these increased demands.
Cell Structure or Shape
varies with function ex: Red blood cells are spherical to move through capillaries with least amount of friction. certain types of white blood cells can change their shape to surround and engulf foreign bacteria.
Cell or plasma membrane
separates cells from external environment. It is said to be semi or selectively permeable. the cell membrane is composed of a lipidbilayer with proteins and carbohydrates all with a significant function.
Water loving lipids orientation
they are orientated so that their polar hydrophilic components are adjacent to aqueous environments.
the non-plar, water fearing hydrocarbon chains are positioned away from water, towards the center of cell membrane.
Proteins in lipids
they act as attachment sites for molecules in the extra cellular fluid and they form channels to transport substances in and out of fells
The position of the lipids, proteins, and carbs
they constantly change due to changes in cellular demands throughout the course of each day. because of this ever-changing patterns of organic components in the cell membrane, it is referred to as fluid mosaic model
Fluid Mosaic Model
The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids.
most numerous of all organelles, unlike most other organelles are not membrane-bound. Their main function is to organize protein synthesis (building)
Endoplasmic Reticulum (E.R.)
folded sacs and tunnels found throughout the cell. Prepares proteins for export and synthesizes steroids
processes and packages substances produced by the cell. ex. Lysosomes are packaged by the golgi apparatus
packages of digestive enzymes that digest food molecules and recycle worn-out cell pars, found only in animal cells. Functionally similar to the vacuoles found in plant cells
carry out cellular respiration- the chemical breakdown of glucose to provide useable energy in the form of ATP which is used to power all cellular activity. These organelles are most numerous in cells with high energy requirements such as muscle cells.
stores DNA and synthesizes RNA. Surrounded by a double walled membrane called the nuclear envelope through which substances may enter and exit via nuclear pores. Contains one or more circular organelles called nucleoli which function to synthesize ribosomes.
plants. found in addition to a cell membrane, cell wall is outermost covering. Composed primarily of polysaccharides Cellulose
store water, wastes, enzymes, toxins. they are functionally similar to lysosomes in animal cells.
Levels of Organization
cells make up tissues, tissues make up organs, organs make up organ systems, and organ systems make up multi cellular organism.
a group of genetically identical cells that live in closely connected groups. Ex: bryozoans
Similarities between colonial organisms and unicellular beasties
Each individual is capable of living independently and do not have tissue and organs
Similarities beween colonial organisms and multicellular beasties
there composed of many cells and do exhibit some cell specialization
Endoplasmic reticulum (E.R.) and Golgi apparatus
Substances produced in a cell and exported outside of the cell would pass through the...
Nucleus, chloroplasts, and mitochondria
organelles that are surrounded by two membranes and contain DNA are the...
short, hair-like structures made of microtubules that enable movement of cells or movement of materials outside a cell
long, thin, whip-like structures, with a core of microtubules, that enable some cells to move
What regulates cell size? Why is this so important? What happens when it changes size?
Surface area to volume ratio; through surface area cell gets food and such; surface area to volume changes
Describe the composition, components, and orientation of organic compounds in region 1. Why is the cell membrane called a fluid mosaic model?
Composed of a lipid bilayer with proteins and carbs all with a specific function. Lipids are oriented so their polar, water- loving, hydrophyllic components are adjacent to aqueous environments. The nonpolar , water-fearing hydrocarbon chains are positioned away from water towards the center of the cell membrane. The proteins act as attachment sutes for molecules in the extracellular fluid + they form channels to transport substances in and out of cells; the position of lipids, proteins, and carbs constantly changes due to changes in cellular demands. This ever changing pattern makes it a fluid mosaic model.
Describe 2 differences between prokaryotic and eukaryotic cells. Examples
Prokaryotic cells lack an organized nucleus and membrane- bound organelles eukaryotic have these. Prokaryotic- bacteria. Eukaryotic- anything but bacteria
has many ribosomes on its surface and is indicative of cells that synthesize numerous proteins for export