Chapter 6: A Tour Of The Cell Flashcards
Light Microscope
An optical instrument with lenses that refract visible light to magnify images of specimens
Electron Microscope
A microscope that uses magnets to focus an electron beam on or through a specimen, resulting in a practical resolution that is 100-fold greater than that of a light microscope using standard techniques
Transmission Electron Microscope
A microscope that passes an electron beam through very thin section stained with metal atoms and is primarily used to study the internal structure of cells.
Scanning electron microscope
A microscope that uses electron beam to scan the surface of a sample, coated with metal atoms, to study details of its topography
Cell fractionation
The disruption of a cell and separation of its parts by centrifugation at successively higher speeds
Plasma Membrane
the membrane at the boundary of every cell that acts as a selective barrier, regulating the cell’s chemical composition
Cytosol
the semifluid portion of the cytoplasm. Sub cellular components are suspended in the cytosol.
Eukaryotic cells
A type of cell with membrane enclosed Nucleus and membrane enclosed organelles
- DNA in Nucleus and has multiple linear chromosomes
- has internal membranes that divide the cell into compartments that provide local environments so incompatible processes can occur simultaneously in a single cell.
Prokaryotic cells
A type of cell lacking a membrane-enclose Nucleus and membrane enclose organelles
- DNA in concentrated in a region that is not membrane enclosed called the nucleoid
- Has a singular, circular chromosome.
Cell Wall
A protective layer external to the plasma membrane in the cells of plants. The cell wall is composed of cellulose. It protects the plant cell, maintains its shape, and prevents the excessive uptake of water
Plasmodesmata
An open channel through the cell wall that connects the cytoplasm of adjacent plant cells, allowing water, small solutes, and some larger molecules to pass between cells
Organelles that plant cells have and animal cells do not
Chloroplast, Plastids, and a central vacuole
Extracellular matrix
The meshwork surrounding animal cells. Regulates cell behavior and communication through integrins
Integrin
A transmembrane receptor protein with two subs units that interconnect the extracellular matrix and the cytoskeleton
Tight Junction
Animal junction that forms a continuous seal around the cell
Desmosomes
Animal junction that functions like rivets, fastening cells into strong sheets
Gap Junctions
Animal cell junction that Provides Cytoplasmic channels from one cell to an adjacent cell
- creates pores which small molecules may pass through
- necessary for communication
Organelles that animal cell have and plant cells do not
Centrosomes and lysosome
Nucleus
The organelle of a eukaryotic cell that contains the genetic material in the form of chromosomes, which are made up of chromatin
Nuclear envelope
The double membrane that surrounds the nucleus, perforated with pores that regulate the traffic within the cytoplasm. The outer membrane is continuous with the ER
Nuclear Laminate
A netlike array of protein filaments that lines the inner surface of the nuclear envelope and helps maintain the shape of the nucleus
Chromosomes
A cellular structure consisting of one DNA molecule and associated protein molecules.
Chromatin
The complex of DNA and proteins that make up eukaryotic chromosomes. When the cell is not dividing chromatin exists in dispersed form, as a mass of very long, thin fibers.
- as the cell gets ready to divide the chromatin coils together and forms distinct chromosomes