Biology Chapter 3

  1. Prokaryotic Cells
    -characterize the organisms of the domains Bacteria and Archaea, known as Prokaryotes
  2. Eukaryotic Cells
    -Organisms of the domain Eukarya-Protists, plants, fungi, and animals

    • Unlike Prokaryotic Cells:
    • -have organelles
    • -nucleus
    • -more complex
  3. Plasma Membrane
    • -A thin outer membrane that bounds the cell.
    • -Regulates the traffic of molecules between the cell and its surroundings
    • -composed of mostly lipids and proteins
  4. Ribosomes
    • -All cells have this
    • -Tiny structures that build proteins according to instructions from DNA

    • -responsible for protein synthesis
    • -in the eukaryotic cells, the components of ribosomes are made in the nucleus, then transported through the pores of the nucleus into the cytoplasm, making proteins that remain in the fluid
    • -other ribosomes are attached to the outside of an organelle called the Endoplasmic Reticulum, making proteins that are incorporated into membranes or secreted by the cell.
  5. Organelles
    • -"little organs"
    • -membrane-enclosed structures that perfrom specific functions.
    • -Most important is the nucleus
  6. Nucleus
    -Houses most of a Eukaryotic Cell's DNA and its surrounded by a double membrane.
  7. Cytoplasm
    • -The entire region of the cell between the nucleus and plasma membrane
    • -In a Eukaryotic cell it consists of various organelles suspended in fluid
  8. Chloroplasts
    • -Only in plant cells
    • -organelles that convert light energy to the chemical energy of food
  9. Phospholipid
    • -two fatty acid tails and a phosphate head (combo of phosporus and oxygen)
    • -phosphate head makes it hydrophilic on the head part only and it is still hydrophobic on the fatty acid tails.
    • -makes phospholipid bilayer when it forms two layers of phospholipid on the cell wall (inner and out)
  10. fluid mosaic
    -a membrane is a fluid mosaic because the molecules can move feely past one another and a mosaic becaue of the diversity of proteins that float like icebergs in the phospholipid sea.
  11. Extracellular matrix
    • -the sticky coat most animal cells secrete
    • -this layer holds cells together in tissues
  12. Cell Junctions
    • -Most animal cells structures contain these
    • -structures that connect to other cells
    • -allow cells ina tissue to function in a coordinated way
  13. Nuclear Envelope
    • Double membrane that borders the nucleus
    • -each membrane of the nuclear envelope is similar in structure to the plasma membrane
    • -pores in the envelope allow certain materials to pass btwn the nucleus and the cytoplasm.
  14. Chromatin
    • -fibers made from long DNA molecules and associated proteins within the nucleus
    • -each chromatin fiber constitues one chromosome
  15. Chromosome
    • -make up chromatin
    • -the number of chromosomes ina cell depends on the species (ex: humans= 46)
  16. Nucleolus
    • -prominent structure within the nucleus
    • -site where the components of ribosomes are made
  17. How DNA directs Protein Production
    1. Dna programs protein production in the cytoplasm by transferring its coded information to a molecule called messenger RNA (mRNA). Like a middle manager, the RNA molecule then carries the order to "build this type of protein" from teh nucleus to the cytoplasm.

    2. The mRNA exits through pores in teh nuclear envelope and travels tot he cytoplasm, where it then binds to ribosomes.

    3. As a ribsome moves along the mRNA, the genetic message is translated into a protein with a specific amino acid sequence
  18. Endomembrane System
    -this system includes the nuclear envelope, the endoplsmic reticulum, the Golgi Apparatus, lysosomes, and vacuoles.
  19. Endoplasmic Reticulum (ER)
    • -one of the main manufacturing facilities wihtin a cell
    • -produces an enormous variety of molecules
    • -connected to the nuclear envelope
    • -2 components make up the ER: rough ER and smooth ER
  20. Rough ER
    • -roughness is due to ribosoms that stud the outside of the ER membrane.
    • -these ribosomes produce membrane protiens and secretory proteins.
    • -some newly manufactured membrane proteins are embedded right in the rough ER membrane, so it creates new membrane and also secrete protein outside of hte cell
    • -some products manufactured by the rough ER are dispatched to other locations in the cell by means of transport vesicles (membranous spheres that bud form the rough ER)
  21. Smooth ER
    • -this organelle lacks the ribosomes that populate the surface of rough ER
    • -performs many functions because of the diversity of enzymes build into the smooth ER
  22. Golgi Apparatus
    • -refinery, warehouse, and shipping center
    • -recieves, refines, stores, and distributes chemical products of the cell
    • -products made in teh ER reach the Golgi in transport vesicles
  23. Lysosomes
    • -a sac of digestive enzymes found in animal cells
    • -absent from most plant cells
    • -develop from vesicles that bud off from teh Golgi
    • -Enzymes within a lysosome can break down large molecules such as protiens, polysaccharides, fats, and nucleic acids.
    • -the lysosome provides a compartment where the cell can digest these molecules safetly, without unleashing these digestive enzymes ont he cell itself
  24. Vacuoles
    • -sacs that bud from the ER, Golgie, or plasma membrane
    • -come in different sizes and have variety of functions

    • -central vacuole: can account for more than half the volume of a plant cell
    • -cv of a plant cell stores organic nutrients, such as proteins stockpiled in the vauoles of seed cells. also contributes to plant gorwth by absorbing water and causing cells to expand.
  25. Chloroplasts
    • -unique to photosynthetic cells of plants and algae
    • -perform photosynthesis
    • -partitioned into 3 major compartments by internal membranes
    • -one compartment is grana: thick fluid within the chloroplasts, chloroplats solar packs, trap light energy and convert to chemical energy.
  26. Mitochondria
    • -sites of cellular respiration, a process that harvests energy from sugars and other food molecules and converts it to another form of chemical energy called ATP.
    • -cells use molecules of ATP as the direct energy source for most of their work.
    • -found in all eukaryotic cells
    • -an envelope of 2 membranes encloses the mitochondrion
    • -inner membrane has numerous infoldings called cristae many enzymes and other molecules that function in cellular respiration are built into the innermembrane so by increasing the surface area of this membrane, the cristae maximize ATP output.
  27. Cytoskeleton
    • -cells infrastructure
    • -network of fibers extending throughout the cytoplsm.
    • -serves as both skeleton and "muscles" for the cell, so support and movement
    • -contains several types of fibers made from diff types of protein like microtubles: straight, hollow tubes composed of proteins.
    • also intermediate filaments and microfilaments that are thinner and solid.
  28. flagella
    • -eukaryotic flagella propel the cell by an undulating whiplike motion.
    • -ex is sperm tail
  29. Cilia
    • -generally shorter and more numerous than flagella
    • -promote movement by a coordinated back and forth motion
    • -like flagella, propel various protists through water and also core of microtubles wrapped in an extension of the plasma membrane.
    • -in your windpipe to clean mucus trapped in your lungs
Card Set
Biology Chapter 3
Chapter 3 Key Terms and Notes