Are the basic unit of structure and function in organisms
all living things are composed of one or more cells
all cell come only from other cells
Bacteria or archaea(another microspic life form)
do not have a nucleus
single - celled organisms
DNA is coiled into a "nucleoid" region that is not separated from the rest of the cell by a membrane
one type of organell
muche smaller, than eukaryote
All plants, animals(humans), fungi
highly organized structures inside teh cells that serve a specialized function
Why are cells so small?
They need a lot of surface area to export and import materials throught the plasma membrane
Small cells have a greater surface area to volume ration than large cells
As a cell grows bigger, its volume increases more rapidly than its surface area
fluid in which organells are immearged
a network of protein filaments that function in:
transport of materials
Helps cell to maintain their shape
dismantle and reform
2. Intermediate Filaments
Changes in cell shape
Provide structural support
Help cell move or capture prey
Maintenance of cell shape
Stabilize the position of the mucleus and other organelles
Are the most permanent element of the cytoskeleton
Maintenance of cell shape, movement of organelles, cell mobility(cilia and flagella)
Act as track to trasport vesicles
guide the movement of chromosomes when cell divide
form the underlying structure for two kinds of cell extensions, cilia and flagella
region of the cell inside the plasma membrane but outside the nucleus
Contains a cell's DNA
The site where new DNA is synthesized
is lined bya double membrane called nuclear envelope
: microscopic channels
Instructions from DNA are copied onto mRNA
mRNA moves to free-stending ribosome
Ribosome reads mRNA instructions and start to build a chain of amino acids
Ribosomes migrate to rough ER and dock, and amino acid chain enters the ER
Inside the ER, amino acid chain folds up and becomes a protein
Proteins are trasported from the rough ER to Golgi complex for additional processing and for sorting.
At golgi complex, a network of membranes that processes and distributes proteins (it edits, sorts, packages, and ships proteins)
Transport vesicles bud off from the golgi complex and transported out of the cell.
through which things exit the nucleus to cytoplasm
organell that serves as the site of protein synthesis in the cell. Ribosomes make a little chain of amino acid and stop becuase there will be a signal saying that "ER processing needed" and it will go to ER to complete the process of making a protein.
Some ribosomes will ramain free-standing and make proteins that will be used in the cell's cytoplasm or nucleus.
are made of mixture of proteins and ribosomal RNA (rRNA)
rRNA is produced in the nucleolus
Only type of organell that is not lined by a membrane
Only type of organell present in prokaryotic cells
a network of membranes that aid in the processing of proteins in eukaryotic cells.
the area within the nucleus of a cell devoted to the production of ribosomal RNA
the membrane lined sphere that move whithin this network, carryiing proteins and other molecules.
These vesicles are propelled along the cytoskeleton.
an interactive group of membrane-lined organelles and trasport vesicles whinin eukaryotic cells. A unique property of a membrane to bud off from one organell and fuse with another releasing its content.
is a network of membranes that processes and distributes protein that come to it from the rough ER.
Act as a distirbution center, putting chemical tags.
Lacks the ribosomes that cover rough ER
Does not participate in protein synthesis
Synthesizes lipids (fats) by the cells of liver and fat cells. (steroids) by cell of ovaries and testes.
Detoxifies harmful substances mostly in the liver cells.
Organelles that digest worn out cellular materials and foreign materials
Fuse with the membrane of a worn-out organelle and engulf it
Filled with numerous enzymes that break down large molecules.
Return smaller usable molecules back to the cytosol
The "powerhouses" of cells
Extract energy from food and convert it into ATP
ATP energy is used to power cellular functions
hair like growths that move back and forth rapidly to move a cell to move material around a cell
long tail like extensions that function in cell movement
Composed mostly of water
Contains many other substances:
Hydrogen ions - to keep cell's cytoplasm at a near neutral pH.
Outer protective lining
Helps cells maintain their shape
Prevents cells from absorbing too much water
Composed primarliy of cellolose, a polysaccharide
Animal cell never have cell walls.
Organelles where photosynthesisi takes place
Only pant and algae cells have them
Interactions between plant cells
Most plant cells are linked together into tissues
PLasmadesmata, tiny pores between cells, allow for the movement of materials ( cytoplasm of one cell continious with the other)
Permanent open chennel between cells.
Interactions between animal cells
Gap junction: clusters of protein strucutres that span tha plasma mabrane of a cell
Tubes of adjacent cells line up and allow for the passage of molecules and electrical signals.