Chapter 6: Cell Structures

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Chapter 6 Cell Structures Their Functions
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6.1 Cell Study Technology

• All living things are made of cells!
• (Remember its one of our characteristics of
  life)
• A living thing can be made of one cell or
  trillions of them.

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6.1 Cell Study Technology

• Examples of multicellular organisms animals,
  plants, fungi
• Examples of unicellular organisms algae,
  bacteria, yeast

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6.1 Cell Study Technology

• THE CELL THEORY
• 1. Cells, or products made by cells, are the
  units of structure function in organisms.
• (All living things are made up of cells)
• 2. All cells come from preexisting cells.
• (Cells can only come from other cells.)

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6.1 Cell Study Technology

• Technological Advances
• Improved microscopes dictated the progress of
  cell study. As microscopes got more advanced,
  scientists could study more complex aspects of
  the cell.

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6.1 Cell Study Technology

• Technological Advances
• Electron microscopes reveal the tiniest cell
  parts with tremendous magnification HOWEVER, you
  can only examine non-living cells

Picture of a hair using an electron microscope
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6.1 Cell Study Technology

• Cell Size
• Cells vary greatly in size, but on average they
  are 10 20 µm (micrometers 10-6m)

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6.2 Two Basic Types of Cells

• All living things fall into one of two categories
  of cells
• 1. Prokaryotes (simple cells)
• Example Any bacteria (E. Coli, Salmonella,
  Streptococcus, etc.)
• Found everywhere
• Size/Structure very small, unicellular, have NO
  membrane-bound organelles so that means NO
  NUCLEUS

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6.2 Two Basic Types of Cells

• All living things fall into one of two categories
  of cells
• 2. Eukaryotes
• More complex than prokaryotes
• Examples Animals, Plants, Fungi
• Have many parts that each have their own function
  advantageous
• Biggest difference presence of NUCLEUS other
  membrane-bound parts
• Nucleus membrane-bound structure that contains
  DNA

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6.3 Prokaryotic Cell Structure
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6.3 Prokaryotic Cell Structure

• Nucleoid the nuclear region of a prokayrotic
  cell, in which the chromosome is attached to the
  plasma membrane

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6.3 Prokaryotic Cell Structure

• Plasmid Circular DNA molecules found in
  prokaryotic cells that contain a few genes that
  help the bacteria survive under specific
  conditions.

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6.3 Prokaryotic Cell Structure

• Bacterial cells typically come in 3 shapes
• 1. Bacilli rod shaped

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6.3 Prokaryotic Cell Structure

• 2. Coccus spherical

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6.3 Prokaryotic Cell Structure

• 3. Spirillum corkscrew shaped

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6.3 Prokaryotic Cell Structure

• Many prokaryotic cells have flagella.
• Flagella long, whiplike extensions made of
  protein that rotate like propellers, allowing
  cells to swim through water or other fluids

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6.4 Eukaryotic Cell Structure

• Organelles small functional cell parts each
  have their own structure function
• Compartmentalization makes eukaryotic cells more
  efficient b/c processes can be separated which
  allows for division of labor.

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6.4 Eukaryotic Cell Structure

• Cell Wall
• A rigid structure that surrounds plant fungal
  cells (NOT ANIMAL CELLS) used for support
  protection
• One of the biggest differences between plant
  animal cells.

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6.4 Eukaryotic Cell Structure

• Centriole
• Tubular structures in animal, algae, some
  fungal cells (NOT IN PLANTS) that play a role in
  cell division/reproduction
• Another difference between plant animal
  cells)

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6.4 Eukaryotic Cell Structure

• Chloroplast
• Double-membrane organelle in plant cells (NOT IN
  ANIMAL CELLS) in which photosynthesis occurs
• Another major difference between animal
  plant cells

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6.4 Eukaryotic Cell Structure

• Cilia
• Short flagella surrounding the cell that are used
  for movement of the cell or moving material along
  a cell/tissue

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6.4 Eukaryotic Cell Structure

• Cytoplasm (Cytosol)
• The gel-like substance that fills the cell in
  which the organelles are bathed

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6.4 Eukaryotic Cell Structure

• Cytoskeleton
• Fine protein fibers that help shape the cell
  organize the cytoplasm can help move eukaryotic
  cells can hold organelles in place or move them
  around

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6.4 Eukaryotic Cell Structure

• Endoplasmic Reticulum (ER)
• A system of membranes that form tubes channels
  used to transport proteins other substances

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6.4 Eukaryotic Cell Structure

• Flagella
• Found in some eukaryotic cells found within the
  plasma membrane used for motion

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6.4 Eukaryotic Cell Structure

• Golgi Apparatus
• A series of membranous sacs that packages
  materials in vesicles for movement around the
  cell or export out of the cell

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6.4 Eukaryotic Cell Structure

• Lysosome
• Special vesicle in animal cells (NOT IN PLANT
  CELLS) that contains enzymes to break down food
  digest food

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6.4 Eukaryotic Cell Structure

• Mitochondrion
• A double-membraned organelle which is the major
  site of ATP synthesis power plant of cell

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6.4 Eukaryotic Cell Structure

• Nucleolus
• An area within the nucleus where RNA is
  synthesized

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6.4 Eukaryotic Cell Structure

• Nucleus
• Organelle surrounded by a nuclear membrane
  considered the genetic control center b/c it
  contains chromosomes (strands of DNA)
• Major difference of prokaryotes vs.
  eukaryotes

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6.4 Eukaryotic Cell Structure

• Plasma Membrane
• (Cell Membrane)
• Surrounds all types of cells (prokaryotic
  eukaryotic) is responsible for letting
  substances into out of the cell
• -Not a source of protection.

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6.4 Eukaryotic Cell Structure

• Ribosomes
• Small bodies of RNA that catalyze the synthesis
  of proteins can be found floating in cytoplasm
  or attached to the ER

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6.4 Eukaryotic Cell Structure

• Vacuole
• Vesicles in a cell that store water food (among
  some other substances)
• Make up a huge percentage of volume of plants
  cells (give plants their rigidity) They are
  present in animal cells also, but they are much
  smaller in size.

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6.5 Cooperation among Cells

• Division of unicellular organisms
• When single-celled organisms divide, some remain
  in a cluster (NOT A MULTI-CELLULAR ORGANISM).
• Each cell could break away and live
  individually

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6.5 Cooperation among Cells

• Colonies groups of unicellular organisms living
  together ex Volvox

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6.5 Cooperation among Cells

• Colonies
• Advantage act together do things more
  efficiently than a single cell
• For example Volvox (type of alga) tend to form
  colonies If in a colony, all the cells can use
  their flagella in a certain way to move the whole
  group vs. moving flagella independently moving
  randomly

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6.6 Division of Labor

• Problem of large, multicellular organisms
• Need to transport materials across a large
  surface area (inner cells very far away from
  environment)

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6.6 Division of Labor

• Solution to problem Increase your internal
  surface area (by organizing cells into blood
  vessels, lungs, leaves, intestines, etc.) that
  can help transport materials

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6.6 Division of Labor

• Requirement Need to have many specialized cell
  types
• Examples
• Gland cell makes chemicals
• Nerve cell conducts electric signals
• Muscle cell specialized for movement

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6.6 Division of Labor

• Cells of larger organisms are more distinctive in
  appearance

Red blood cells
Nerve Cell
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6.6 Division of Labor

• Tissue group of cells with same function
• ex epidermal (skin) cells of hydra
• cells lining our stomachs

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6.6 Division of Labor

• Organ group of tissues working together
• Ex lungs, heart, eye, fruits, leaves, stomach

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6.6 Division of Labor

• System group of organs working together
• Ex Circulatory system includes the heart,
  vessels, etc (all organs)

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6.7 Systems

• Why do we need systems?
• In larger organisms, many cells are buried too
  far inside the organism so they cant exchange
  materials with the environment

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6.7 Systems

• Example of system in animals
• The circulatory system in animals delivers
  nutrients and oxygen and takes away wastes from
  cells all over the body.

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6.7 Systems

• Example of system in plants
• Water food are transported around in a plants
  vascular system (a series of vessels found inside
  the plant)

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Levels of Structure in Biosphere pg 180

• Biospherepart of Earth that has life
• Ecosystem Chesapeake Bay
• Community all organisms in Chesapeake Bay
• Population all striped bass in Chesapeake Bay
• Organism a striped bass

Organelles