Unit III

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Unit III Cell

• Celebrating Every Living Link

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CELL

• What is a cell?
• What are cells made of?
• Where do we find cells?

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CELL

• The smallest unit of matter that can carry on all
  life processes
• The basic unit of life

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I. Cell Theory

• A. All living things are composed of cells.
• B. Cells are the basic units of structure and
  function in living things.
• C. New cells are produced from existing cells.

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II. Cells

• A. Size
• 1. large enough to see with the naked eye (2 m)
• 2. to 0.02 micrometers (µm)
• B. Various shapes

Neuron - http//www.emc.maricopa.edu/faculty/farab
ee/BIOBK/neurons_1.gif perenchyma cell -
http//www.emc.maricopa.edu/faculty/farabee/BIOBK/
groundtsa.jpg
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• Types of Cells
• 1. Eukaryote
• a. a cell that contains a nucleus and membrane
  bound organelles
• 2. Prokaryote
• a. a unicellular organism that lacks a nucleus
  and membrane-bound organelles

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• Eukaryotes
• Plants
• Animals
• Fungi
• Protists (algae, slime molds, paramecium)

• Prokayotes
• bacteria

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Prokaryotes
Eukaryotes
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• D. Organelles
• 1. cell component that performs specific
  functions
• E. Cell Membrane (skin)
• 1. thin membrane surrounding the entire cell

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III. Parts of the Eukaryotic Cell

• A. Basic Functions
• 1. take in food
• 2. transform food into energy
• 3. get rid of waste
• 4. reproduce

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• B. 3 Main Components
• 1. Cell Membrane
• a. outer boundary that separates the cell from
  its outer surroundings

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• b. Semipermeable/Selectively Permeable Membrane
• 1) a cell membrane that keeps out some
  molecules, but allows others to pass
• c. 2 lipid layers mixed with protein

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• d. Cell wall
• 1) plants, algae, fungi, and many prokaryotes
• 2) provides support and protection

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• 2. Nucleus (brain)
• a. a large organelle near the middle of the cell
  containing the majority of the cells information
• b. contains DNA and directs the activities of
  the cell
• c. site where nucleic acids are synthesized
  (created)

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• d. Chromatin
• 1) the protein and DNA in the nucleus of a
  non-dividing cell
• 2) when a cell is dividing, the chromatin coils
  up to become the chromosomes

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• 3. Cytoplasm
• a. lies inside the cell and surrounds the
  organelles
• b. gel-like substance (kind of like jello)
• c. contains water, salts, and organic molecules
• d. in constant motion

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• 4. Organelles found in the cytoplasm
• a. ribosomes
• b. endoplasmic reticulum (ER)
• 1) SER
• 2) RER
• c. Golgi apparatus
• d. Mitochondria
• e. Lysosomes
• f. Cytoskeleton (microtubules and microfilaments)

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• g. Cilia
• h. Flagella
• i. Vacuoles
• j. Plastids
• 1) an organelle in which food or pigments are
  stored

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• Chloroplasts
• 1) contain chlorophyll
• 2) the site for photosynthesis
• b) Chromoplasts
• 1) synthesize and store pigments to trap
  sunlight for energy
• c) Leucoplasts
• 1) stores food such as starches, proteins, and
  lipids

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Animal Cells
Plant Cells
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IV. 13 Levels of Organization

• A. Specialization
• 1. cells throughout an organism develop in
  different ways to perform different tasks
• (Cell Theory Cells are the basic units of
  structure and function in living things.)

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p. 191 Bio book

• 2. Red blood cells
• a. transport oxygen
• 3. Pancreatic cells
• a. produces lots of enzymes
• b. has lots of ribosomes and RER
• 4. Muscle cells
• a. contain complex cytoskeleton
• 5. Guard cells
• a. crescent moon shape opens and closes
• b. allowing gases to be exchanged in plants

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• atom of hydrogen
• molecule of protein
• ribosome
• muscle cell

B. All Eukaryotes 1. atom 2. molecule 3.
organelle 4. cell
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• C. Multicellular Eukaryotes
• 5. tissue
• 6. organs
• 7. organ system

Muscle tissue Stomach Digestive system
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Multicellular Organization
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• D/8. Organism (unicellular and multicellular
• 9. population
• 10. community
• 11. ecosystem
• 12. biome
• 13. biosphere

humans at OHS humans/rats/bugs humans/rats/bugs
/ grass/heat temperate deciduous forest
grasslands Earth
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V. Homeostasis and Transport

• A. Passive Transport
• 1. the movement of any substance across a
  membrane without the use of chemical energy
  (osmosis and diffusion)

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Cell Membrane
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• B. Active Transport
• 1. the movement of any substance across a
  membrane with the use of chemical energy

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• C. Homeostasis
• 1. the stable internal conditions of a living
  thing
• 2. cells maintain homeostasis by
• a. eating
• b. drinking
• c. sweating
• d. breathing
• e. excreting

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• D. Passive Transport
• 1. Diffusion
• a. the process by which molecules move from an
  area of greater concentration to an area of
  lesser concentration

Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
Na
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• b. molecules are striving to reach
  equilibrium
• 1) equilibrium the
• concentration of the molecules of a
  substance is the same throughout its space

Na
Na
Na
Na
Na
Na
Na
Na
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• c. Concentration
• 1) the difference in concentration of a
  substance across a space

12 g salt 3 L water
24 g salt 3 L water
24 g salt 6 L water
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8
4
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• 2. Permeable
• a. referring to a membrane through which
  molecules can pass
• b. not all molecules can move through all
  membranes
• 1) depends upon
• a) size of molecule
• b) type of molecule
• c) molecular structure of the
• cell membrane

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• c. Cell membranes are semipermeable
• 1) cell regulates what goes in and out

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• 3. Osmosis
• a. the diffusion of water
• b. solutions
• 1) solute
• 2) solvent
• 3) solution
• c. In organisms
• 1) solute
• a) inorganic and organic compounds
• 2) solvent
• a) water

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Osmosis
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• 4. Direction of flow
• a. depends upon the concentrations of water and
  solutes dissolved in the solutions
• hyper
• hypo
• iso

Higher Lower same
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• b. Hypertonic
• 1) the concentration of solute molecules is
  higher outside than inside a cell
• c. Hypotonic
• 1) the concentration of solute molecules is
  lower outside than inside a cell
• d. Isotonic
• 1) the concentration of solute molecules inside
  and outside a cell are equal

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Hypotonic, Hypertonic, Isotonic
Isotonic
Hypertonic
Hypotonic
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• 5. Facilitated Diffusion
• a. movement of specific molecules across cell
  membranes through protein channels
• b. passive transport uses no energy
• c. uses proteins that are usually specialized
  for one type of molecule
• d. ie glucose is too big to go through many
  cell membranes

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Facilitated Diffusion
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• E. Active Transport
• 1. the movement of any substance across a cell
  membrane with the use of energy from ATP
• 2. Cell Membrane Pumps
• a. movement against the concentration gradient
• b. necessary for the conduction of nerve
  impulses and the contraction of muscles (Na, K)

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Active Transport
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• 3. Endocytosis
• a. the process by which a cell engulfs and
  surrounds large substances
• b. once the contents are inside the cell, they
  are digested by cellular enzymes

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• c. Two types of Endocytosis
• 1) Pinocytosis
• a) the movement into cells of solutes or
  fluids
• 2) Phagocytosis
• a) the engulfing of food by a cell
• b) ie amoeba feeds
• c) ie white blood cell engulfs and digests
  bacteria

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• 4. Exocytosis
• a. the process by which wastes are packaged in
  vesicles and leave the cell
• b. ie proteins are made on
• ribosomes
• and packaged into vesicles by
• golgi apparatus
• the vesicles then fuse with the cell membrane
  and then are dumped out of the cell
• c. used in the nervous and endocrine systems

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CELL

• What is a cell?
• What are cells made of?
• Where do we find cells?