- 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
- membrane-bound nucleus
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:
- cell structure
- cell movement
- transport of materials
- Helps cell to maintain their shape
- dismantle and reform
- Three types:
- 1. Microfilaments
- 2. Intermediate Filaments
- 3. Microtubules
- 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
- Nuclear pores: 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:
- Waste products
- Hydrogen ions - to keep cell's cytoplasm at a near neutral pH.
- Digestive enzymes
- 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.
- Open only as necessary.