Cell Structure & Function Flashcards
The 6 primary tenants of cell theory are:
- All living organisms are made of cells.
- Cells are the basic unit of life.
- All cells arise from preexisting cells.
- Hereditary information is passed from cell to cell.
- All cells have the same basic chemiclal composition.
- Energy flow occurs within cells.
A set of defining principles that describes the characteristics of cells.
Cell Theory
Every cell shares at least 4 key components:
- Every cell has a plasma membrane that separates the cell’s interior environment from its exterior environment.
- Every cell has cytosol, a jelly-like fluid in which intracellular organelles are suspended. Organelles are specialized cellular structures that have specific functions within the cell. The space within the cell that contains cytosol is called cytoplasm.
- Every cell contains chromosomes that carry genes in the form of DNA.
- Every cell also contains ribosomes, which synthesize proteins.
A jelly-like fluid in which intracellular organelles are suspended.
Cytosol
Specialized cellular structures that have specific functions within the cell.
Organelles
The space within the cell that contains the cytosol.
Cytoplasm
Synthesize proteins.
Ribosomes
Simpler of the 2 cell types.
Lack internal division and organization (don’t have a nucleus or other membrane-bound organelles).
Unicellular.
2 major domains —> Archaea and Bacteria.
Prokaryotes
Structures of a prokaryotic cell include:
Pili
Flagellum
Cell Wall
Capsule
Plasma Membrane (Cell Membrane)
Cytoplasm
Ribosomes
Nucleoid
Hair-like appendages found on the cell surface of many bacteria.
Help bacteria adhere to extracellular surfaces.
Pili (Pilus)
Tail-like appendage (found on many bacterial cells) that enables movement.
Flagellum
A rigid layer of sugar-based molecules (surrounding most archaea and bacteria).
Provides structural support and protection to the cell.
Cell Wall
Sugar-containing layer associated with the virulence of bacteria.
Capsule
Microscopic membrane compose of fats and proteins that forms the external boundary between the cell and the outside world.
Composed of phospholipid bilayer —> Selectively permeable membrane that controls the flow of molecules, ions, and proteins into and out of the cell.
Helps protect the cell and helps it to maintain proper internal physiology.
Cell Membrane
Material within a cell enclosed by the cell membrane.
Cytoplasm
Sphere-shaped structures composed of RNA and protein that serve as the site of protein synthesis.
Suspended in the cytoplasm.
Ribosomes
The irregularly shaped region (within prokaryotes) that contains most of the genetic material of the cell —> Have a single circular chromosome.
Nucleoid
Much more complex than prokaryotic cells.
Most are multicellular, some are unicellular.
Contain a membrane-bound nucleus.
Contain membrane-bound organelles.
Contain multiple rod-shaped chromosomes where DNA is stored.
Eukaryotes
Every cell shares at least 4 key components:
Plasma Membrane
Cytosol
Chromosomes
Ribosomes
Phospholipid bilayers with embedded glycoproteins.
Semipermeable and function as an internal regulator (into and out of the cell).
Plasma Membranes
Cells that serve to absorb nutrients from food/blood have ______ along the plasma membrane.
Fingerlike projections that increase the cell’s surface area.
Microvilli
Space between the cell wall and the nucleus —> Fills the cell inside the cellular membrane and holds all cellular material in place.
Organelles are suspended in cytosol within the _______.
Cytoplasm
Specialized subunits that are often enclosed within their own lipid bilayers and are suspended in cytosol in the cytoplasm.
Organelles
Acts as the brain of the cell. —> Directing all cellular activities within other organelles, controlling DNA transcription/synthesis, determining which proteins will be made.
Cellular DNA stored within.
Has its own lipid bilayers that separates it from the cytoplasm.
Nucleus
Double membrane that surrounds the nucleus and offers an extra layer of protection.
Necessary to protect the nucleus (where the cell’s only copy of DNA is housed).
Allows for the passage of RNA, ions, and molecules between the nucleoplasm and cytoplasm.
Nuclear Envelope