Bio week 1 pt 2

  1. Cell theory:
    What are 3 core principles
    Cell theory: the first unifying theory of biology 

    • Cells are the fundamental units of life
    • All organisms are composed of cells
    • All cells come from preexisting cells
  2. Why are cells so small? What do volume and surface area determine?
    • Cells are small because a high surface area-to-volume ratio is essential. 
    • Volume determines the amount of chemical activity in the cell per unit time
    • Surface area determines the amount of substances that can pass the cell boundary per unit time
  3. Define the plasma membrane
    The outer surface of every cell made up of a phospholipid bilayer w/ proteins and other molecules embedded. It has more or less the same structure in all cells
  4. The phospholipid bilayer is not ____, but more like an ____ fluid in which the _____ & _____ are in constant motion
    • rigid 
    • oily 
    • proteins & lipids
  5. 4 characteristics of the plasma membrane
    • is a selectively permeable barrier 
    • allows cells to maintain a constant internal environment 
    • is important in communicating & receiving signals
    • often has proteins for binding and adhering to adjacent cells
  6. Two types of cells
    • Prokaryotic cells
    • Eukaryotic cells
  7. 2 types of prokaryotic cells
    bacteria & archaea
  8. In eukaryotic cells, the DNA is in a __________ compartment called the ______
    • membrane-enclosed compartment
    • nucleus
  9. Prokaryotes are enclosed by a ____ _____. Their DNA is contained in the _____.
    • plasma membrane 
    • nucleoid
  10. The cytoplasm of prokaryotes consists of _____ and ____
    cytosol (water and dissolved material) & suspended particles
  11. Ribosomes
    sites of protein synthesis found in prokaryotes and eukaryotes
  12. Eukaryotes haves other _____ _____ ____ (____) in which specific chemical reaction occur.
    membrane enclosed compartments (organelles)
  13. State 4 characteristics of the nucleus
    • usually the largest organelle
    • contains the DNA
    • site of DNA replication
    • site where gene transcription is turned on or off
  14. Name an activity that begins in the nucleolus
    assembly of ribosomes
  15. The nucleus is surrounded by a double membrane structure?
    the nuclear envelope
  16. ____ ____ in the envelope control movement of molecules between _____ and _____
    • nuclear pores
    • nucleus and cytoplasm
  17. some large molecules (like _____) must have a certain amino acid sequence known as a _____ ____ _____ to cross the nuclear envelope
    • proteins
    • nuclear localization signal
  18. The endomembrane system consists of (5)
    • plasma membrane
    • nuclear envelope 
    • endoplasmic reticulum
    • golgi apparatus
    • lysosomes
  19. Tiny ____ _____ _____ shuttle substances between various components of the endomembrane system
    membrane surrounded vesicles
  20. Endoplasmic reticulum function:
    • synthesis of new proteins (RER)
    • synthesis of lipids, oils, phospholipids, & steroids (SER).
  21. ____(SER/RER) does NOT have ribosomes
    smooth endoplasmic reticulum (SER)
  22. endoplasmic reticulum
    it is a network of interconnected membranes in the cytoplasm; has large surface area
  23. In ER, newly synthesized proteins are transported into the ____ ____. It then does what to the protien?
    • RER lumen
    • modifes, folds, and transorts protein
  24. Ribosomes consists of more than ___ ____ ____ molecules and are _____ bonded to ______ RNA
    • 50 different protein molecules 
    • noncovalently 
    • ribosomal RNA
  25. ______ are considered little factories for proteins. They also float freely in ______ cells
    • Ribosomes
    • prokaryotes
  26. 3 characteristics of ribosomes in eukaryotes
    • found in cytoplasm free or attached to the ER
    • found inside mitochondria and chloroplasts
    • in neurons can found over a meter from the cell body
  27. _____ are NOT considered an organelle
    ribosomes
  28. The golgi apparatus is composed of?
    • flattened sacs (cisternae)
    • small membrane enclosed vesicles
  29. 3 functions of golgi apparatus
    • receives proteins from RER (can further modify them)
    • concentrates, packages & sorts proteins
    • adds and modifies carbohydrates to proteins
  30. The cis region receives _____ (a piece of the ER that buds off) from the ___
    • vesicles
    • ER
  31. In the golgi apparatus, what occurs at the trans region?
    Vesicles bud off from the golgi apparatus and are moved to the plasma membrane or other organelles
  32. Primary lysosomes originate from the ___ ____. They contain ____ ____ (also state function)
    • golgi apparatus 
    • digestive enzymes that hydrolyze macromolecules into monomers
  33. Food molecules enter the cell (lysosomes) via _____. What is formed?
    • phagocytosis
    • phagosome
  34. Phagosomes fuse with ____ _____ to form ____ _____. Enzymes in the ____ ____ hydrolyze the ____ ____
    • primary lysosomes 
    • secondary lysosomes 
    • secondary lysosomes 
    • food molecules
  35. Lysosomes also digest cell materials (what is this process called?)
    autophagy
  36. Cell components of lysosomes are frequently?
    destroyed and replaced by new ones
  37. In the ______, energy in fuel molecules is transformed to the bonds of ____ ___ ___. This process is called ____ ____
    • mitochondria
    • energy rich ATP 
    • cellular respiration
  38. Cells that require of energy have a lot of _____
    mitochondria
  39. Two membranes of mitochondria
    • inner membrane: folds inward to form cristae
    • outer layer
  40. The cristae creates?
    a large surface area for proteins involved in cellular respiration reactions
  41. the mitochondrial matrix consists of: (3)
    • enzymes
    • DNA
    • ribosomes
  42. Chloroplasts have a ___ ____ & are the site of ______. During this process, what occurs.
    • double membrane 
    • photosynthesis
    • energy is converted to the energy of chemical bonds
  43. Three major structures within chloroplasts
    • grana
    • thylakoids 
    • stroma
  44. _____ are stacks of thylakoids (what are thylakoids made of?)
    • grana
    • made of circular compartments of the inner membrane
  45. Thylakoids contain _____ and other ____ that harvest light energy for photosynthesis
    • chlorophyll 
    • pigments
  46. Define stroma and state 2 things it contains
    • fluid within chloroplasts in which grana are suspended
    • contains DNA and ribosomes
  47. Some organelles may have arose via ______ (living together)
    symbiosis
  48. The endosymbiosis theory
    proposes that mitochondria and plastids arose when one cell engulfed another cell
  49. 2 factors that support the endosymbiosis theory
    • The discovery of a single-celled eukaryote, hatena, that ingests a green alga (Nephroselmis)
    • The green alga loses most of its structures and acts as a chloroplast
  50. 4 functions of cytoskeleton
    • holds organelles in position or moves them 
    • cytoplasmic streaming 
    • changes the shape of the cell
    • interacts with extracellular structures to stabilize the cells
  51. The cytoskeleton's ability to change the shape of the cell is critical for?
    Neurons (development, injury, learning and memory)
  52. 3 components of the cytoskeleton
    • microfilaments
    • intermediate filaments
    • microtubules
  53. 4 characteristics of microfilaments
    • help a cell or parts of a cell to move 
    • determine cell shape 
    • made from the protein actin
  54. Actin has _ & _ ends and polymerizes to form?
    • + and - ends
    • long helical chains (reversible)
  55. In some cells, microfilaments form a ______ just inside the ____ ____
    • meshwork
    • plasma membrane
  56. Purpose of the meshwork
    provides structure, for example in the microvilli that line the human intestine
  57. 4 characteristics of intermediate filaments
    • tough, ropelike protein assemblages
    • anchor cell structures in place 
    • resist tension 
    • axon growth
  58. 4 characteristics of microtubules
    • form rigid internal skeleton in some cells
    • made from the protein tubulin (a dimer)
    • have + and - ends 
    • can change length rapidly by adding and losing dimers
Author
chikeokjr
ID
323385
Card Set
Bio week 1 pt 2
Description
Working units of life
Updated