Ch 4

• 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
• multicellular

highly organized structures inside teh cells that serve a specialized function

• 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:
• Nutrients
• 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

• 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.

• 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.