Cells

							Cells—the fundamental unit of life
    •   What is life?
    •   Molecules of life
    •   Cell as fundamental unit
    •   Cell membranes and organelles
    •   Cell metabolism
    •   Cells organized into tissues
    •   Types of tissues

                                           Larry M. Frolich, Ph.D.
                             Biology Department, Yavapai College
Cells—the fundamental unit of life

    •What is life?
    •   Molecules of life
    •   Cell as fundamental unit
    •   Cell membranes and organelles
    •   Cell metabolism
    •   Cells organized into tissues
    •   Types of tissues




                                                      Larry M. Frolich, Ph.D.
                                        Biology Department, Yavapai College
What is Life?
• Life needs energy
• Life reproduces
• Life grows and
  develops
• Life maintains a
  stable condition—
  homeostasis
• Life responds to
  stimulus
• Life is organized
  because it has
  evolved                           Larry M. Frolich, Ph.D.
                      Biology Department, Yavapai College
Humans Evolve
• Life is organized
  hierarchically
• Evolution explains
  organization at every
  level of hierarchy
• Humans can be
  understood at every
  level of hierarchy
• Humans have
  evolved and are
  evolving
                        Larry M. Frolich, Ph.D.
          Biology Department, Yavapai College
Cells are fundamental unit of life

• Cells are the basic
  and fundamental
  unit of life
• The first life was
  cellular life
• The Molecules of
  Life are what cells
  and all their
  internal parts are
  made up of


                                                   Larry M. Frolich, Ph.D.
                                     Biology Department, Yavapai College
Cells—the fundamental unit of life
    • What is life?


    •Molecules of life
    •   Cell as fundamental unit
    •   Cell membranes and organelles
    •   Cell metabolism
    •   Cells organized into tissues
    •   Types of tissues




                                                      Larry M. Frolich, Ph.D.
                                        Biology Department, Yavapai College
The Carbon-chain Molecules of Life
MOLECULE        MADE OF         FUNCTION
Carbohydrates   Simple Sugars   Energy

Proteins        Amino Acids     Catalyze
                                reactions
Fats            Fatty Acids     Cell
                                membranes
DNA/RNA         Nucleotides     Information
                (bases)

                                                   Larry M. Frolich, Ph.D.
                                     Biology Department, Yavapai College
Carbohydrates
• Components are
  simple sugars
• Used for energy
  storage in complex
  form
• Broken down to
  simple sugars to fuel
  cellular metabolism
  in mitochondria
• So, why are simple
  sugars bad for us?
  And why do we love
  them so much?
  (p. 29 in text)                       Larry M. Frolich, Ph.D.
                          Biology Department, Yavapai College
 Proteins
• Components are
  amino acids
• Very complicated
• Amino acid chain
  folds up to give
  complex form
• Complex form
  allows for
  catalyzing very
  specific chemical
  reactino
• GenBlue                           Larry M. Frolich, Ph.D.
                      Biology Department, Yavapai College
      Fats/Lipids
• Fundamental to life and
  origins—separate cell
  interior from
  environment as cell
  membrane
• Mammals and other
  vertebrates—long-term
  energy storage
• Role in diet=big
  controversy!
                             Larry M. Frolich, Ph.D.
               Biology Department, Yavapai College
DNA/RNA (Nucleic Acids)




• DNA and RNA store and use information
• Components are nucleotides or ―bases‖ (A,C,T/U,G)
• One DNA molecule can be very long and complex—millions of bases
  long
• DNA duplicates to pass on information
• Transcription to mRNA to be translated into protein’s amino acid chain
• What do proteins do?                                               Larry M. Frolich, Ph.D.
                                                       Biology Department, Yavapai College
Cells—the fundamental unit of life
 • What is life?
 • Molecules of life

 • Cell as fundamental unit
 •   Cell membranes and organelles
 •   Cell metabolism
 •   Cells organized into tissues
 •   Types of tissues




                                                   Larry M. Frolich, Ph.D.
                                     Biology Department, Yavapai College
Cells are fundamental unit of life

• Cells are the basic
  and fundamental
  unit of life
• The first life was
  cellular life
• The Molecules of
  Life are what cells
  and all their
  internal parts are
  made up of


                                                   Larry M. Frolich, Ph.D.
                                     Biology Department, Yavapai College
Two types of cells
• Prokaryotic cells
  – Relatively Simple
  – Relatively Small
  – No organelles with Molecules of Life
    distributed throughout cytoplasm
  – Bacteria are all prokaryotic cells
• Eukaryotic cells
  – More complex
  – Much bigger (100 x size of prokaryotic
    cells)
  – Internally organized with membrane-bound
    organelles
  – Multi-cellular organisms, like plants and
    animals, are all made up of eukaryotic cells                 Larry M. Frolich, Ph.D.
                                                   Biology Department, Yavapai College
Eukaryotic cell




                           Larry M. Frolich, Ph.D.
             Biology Department, Yavapai College
Endosymbiotic origin of
mitochondria and
chloroplasts
• Eukaryotic cells evolved from fusion
  or integration of prokaryotic cells
• Best evidence is in bacterial or
  prokaryotic appearance of
  mitochondria and chloroplasts
• These organelles are like little
  bacterial cells within our cells, now
  fully functionally integrated
• They perform fundamental cell
  functions. Mitochondria process
  sugars to produce energy;
  chloroplasts make sugars by
  photosynthesis
• But they maintain their own DNA and
  genetic control

                                   Larry M. Frolich, Ph.D.
                     Biology Department, Yavapai College
    Prokaryotic cells have:
• Cell membrane
• DNA molecule loose in cytoplasm
• Small Ribosomes where proteins are
  assembled from DNA information
• Microtubule structures like flagella and
  cilia
• Mitochondria and chloroplasts share most
  of these features, including their own
  independent DNA
                                                Larry M. Frolich, Ph.D.
                                  Biology Department, Yavapai College
Eukaryotic cells (like our human cells) have:

  WHAT EUKARYOTIC CELLS HAVE:
  • Cell membrane
  • Nucleus
  • Mitochondria (and sometimes chloroplasts for
    photosynthesis)
  • Larger ribosomes for protein assembly from DNA
    information
  • Internal membranes that organize cellular spaces and
    distribution of Molecules of Life within cell (―cytoskeleton‖)




                                                                 Larry M. Frolich, Ph.D.
                                                   Biology Department, Yavapai College
WHAT CAN EUKARYOTIC CELLS                WHAT STRUCTURES ARE
DO?                                      INVOLVED?

Separate inside of cell from external    Cell Membrane
environment and control what
substances pass across membrane
Produce proteins/enzymes that            Nucleus (DNA), Ribosomes on rough
catalyze chemical reactions or control   endoplasmic reticulum
movement across membrane
Break down sugars to form energy         Mitochondria
which is stored in phosphate bonds of
ATP
Organize distribution of Molecules of    Internal membrane system and
Life (macromolecules) and ions           ―cytoskeleton‖ (ER, lysosomes,
throughout cell                          vessicles, microtubules)
Move                                     Flagella, cilia, pseudopods

                                                                           Larry M. Frolich, Ph.D.
                                                             Biology Department, Yavapai College
Cells—the fundamental unit of life
• What is life?
• Molecules of life
• Cell as fundamental unit


•Cell membranes and
 organelles
• Cell metabolism
• Cells organized into tissues
• Types of tissues

                                               Larry M. Frolich, Ph.D.
                                 Biology Department, Yavapai College
A cell membrane or plasma membrane separates cell
from outside world—creates ability to regulate internal
environment (homeostasis)




                                                       Larry M. Frolich, Ph.D.
                                         Biology Department, Yavapai College
          cell membrane




              Larry M. Frolich, Ph.D.
Biology Department, Yavapai College
                                        cell membrane

   What are some characteristics of
      the plasma membrane?
• It is a phospholipid bilayer
• It is embedded with
  proteins that move in
  space
• It contains cholesterol for
  support
• It contains carbohydrates
  on proteins and lipids
• Selectively permeable


                                               Larry M. Frolich, Ph.D.
                                 Biology Department, Yavapai College
                                    cell membrane
 What does selectively permeable
            mean?
• The membrane allows
  some things in while
  keeping other
  substances out




                                        Larry M. Frolich, Ph.D.
                          Biology Department, Yavapai College
                                        cell membrane
 How do things move across the
      plasma membrane?
1.   Diffusion
2.   Osmosis
3.   Facilitated transport
4.   Active transport
5.   Endocytosis and exocytosis



                                                Larry M. Frolich, Ph.D.
                                  Biology Department, Yavapai College
                                     cell membrane

  What are diffusion and osmosis?
• 1. Diffusion is the
  random movement of
  molecules from a
  higher concentration
  to a lower
  concentration

• 2. Osmosis is the
  diffusion of water
  molecules

                                         Larry M. Frolich, Ph.D.
                           Biology Department, Yavapai College
                                             cell membrane

  How does tonicity change a cell?
• Hypertonic solutions have
  more solute than the inside
  of the cell and lead to lysis
  (bursting)

• Hypotonic solutions have less
  solute than the inside of the
  cell and lead to crenation
  (shriveling)

• Isotonic solutions have equal
  amounts of solute inside and
  outside the cell and thus does
  not affect the cell


                                                 Larry M. Frolich, Ph.D.
                                   Biology Department, Yavapai College
                                          cell membrane
  What are facilitated diffusion and
         active transport?
• 3. Facilitated transport is
  the transport of molecules
  across the plasma
  membrane from higher
  concentration to lower
  concentration via a
  protein carrier

• 4. Active transport is the
  movement of molecules
  from a lower to higher
  concentration using ATP
  as energy; requires a
  protein carrier
                                              Larry M. Frolich, Ph.D.
                                Biology Department, Yavapai College
                                           cell membrane
       What are endocytosis and
             exocytosis?
• 5. Endocytosis transports
  molecules or cells into the
  cell via invagination of the
  plasma membrane to
  form a vesicle

• 6. Exocytosis transports
  molecules outside the cell
  via fusion of a vesicle
  with the plasma
  membrane

                                               Larry M. Frolich, Ph.D.
                                 Biology Department, Yavapai College
           Protein synthesis
• Remember that proteins control cell
  metabolism—how and where are they
  made, or synthesized in the cell?




                                                Larry M. Frolich, Ph.D.
                                  Biology Department, Yavapai College
                            Protein synthesis
  What structures are involved in
       protein synthesis?
• Nucleus
• Ribosomes
• Endomembrane system




                                          Larry M. Frolich, Ph.D.
                            Biology Department, Yavapai College
                              Protein synthesis
        What is the structure and
        function of the nucleus?
• Bound by a porous
  nuclear envelope
• Houses DNA and
  associated proteins
  called chromatin
• Contains nucleoplasm
• Nucleolus region(s)
  that contain ribosomal
  RNA (rRNA)
                                            Larry M. Frolich, Ph.D.
                              Biology Department, Yavapai College
                                  Protein synthesis
 What is the structure and function
           of ribosomes?
• Organelles made of
  RNA and protein
• Found bound to the
  endoplasmic
  reticulum and free
  floating in the cell
• Site of protein
  synthesis


                                          Larry M. Frolich, Ph.D.
                            Biology Department, Yavapai College
                                 Protein synthesis

    What is the endomembrane
              system?
• A series of membranes in which molecules
  are transported in the cell

• It consists of the nuclear envelope,
  endoplasmic reticulum, Golgi apparatus,
  lysosomes and vesicles


                                                Larry M. Frolich, Ph.D.
                                  Biology Department, Yavapai College
How does the endomembrane       Protein synthesis


system function and appear?




                                        Larry M. Frolich, Ph.D.
                          Biology Department, Yavapai College
                                               Protein synthesis
Summary of the parts of the endomembrane
                system?
• Rough endoplasmic reticulum – studded with ribosomes
  used to make proteins

• Smooth endoplasmic reticulum – lacks ribosomes but
  aids in making carbohydrates and lipids

• Golgi apparatus – flattened stacks that process, package
  and deliver proteins and lipids from the ER

• Lysosomes – membranous vesicles made by the Golgi
  that contain digestive enzymes

• Vesicles – small membranous sacs used for transport
                                                           Larry M. Frolich, Ph.D.
                                             Biology Department, Yavapai College
    What are cilia and flagella?
• Both are made of
  microtubules

• Both are used in
  movement

• Cilia are about 20x
  shorter than flagella


                                         Larry M. Frolich, Ph.D.
                           Biology Department, Yavapai College
  What do mitochondria do and
    what do they look like?
• A highly folded
  organelle in
  eukaryotic cells
• Produces energy in
  the form of ATP
• They are thought to
  be derived from an
  engulfed prokaryotic
  cell

                                       Larry M. Frolich, Ph.D.
                         Biology Department, Yavapai College
Cells—the fundamental unit of life
    •   What is life?
    •   Molecules of life
    •   Cell as fundamental unit
    •   Cell membranes and organelles

    • Cell metabolism
    • Cells organized into tissues
    • Types of tissues




                                                      Larry M. Frolich, Ph.D.
                                        Biology Department, Yavapai College
          What is cellular respiration?
•   Occurs in the
    mitochondria
•   Production of ATP
    in a cell
•   Usually glucose is
    main ―energy‖
    molecule enters
    cellular respiration
•   Includes:
    –   Glycolysis
    –   Citric acid cycle
    –   3. Electron
        transport chain


                                                Larry M. Frolich, Ph.D.
                                  Biology Department, Yavapai College
What other molecules besides glucose
 can be used in cellular respiration?

• Other carbohydrates
• Proteins
• Lipids




                                           Larry M. Frolich, Ph.D.
                             Biology Department, Yavapai College
How can a cell make ATP without oxygen?

 • Fermentation
   – Occurs in the cytoplasm
   – Does not require oxygen
   – Involves glycolysis
   – Makes 2 ATP and lactate in human cells
   – Is important in humans for a burst of energy
     for a short time



                                                      Larry M. Frolich, Ph.D.
                                        Biology Department, Yavapai College
        All of cell metabolism
• Cell metabolism is much more than simply making
  ATP, or cellular respiration, which is just how the
  cell has an energy supply.
• What does the cell do with that energy?
• Get ready for what you are about to see…
• The cell runs all the reactions that make it alive—
  see the first part of this presentation: grow,
  reproduce, develop, move, maintain internal
  homeostasis, respond to stimuli.
• This involves a LOT of chemical reactions.
• Here it is: most of the reactions involved in
  keeping the simplest of cells—an E. coli bacteria—
  alive!

                                                      Larry M. Frolich, Ph.D.
                                        Biology Department, Yavapai College
Ecocyc—database of complete E. coli metabolism




                                                    Larry M. Frolich, Ph.D.
                                      Biology Department, Yavapai College
             What’s it all mean?
•   Every little box represents a stage in a particular
    chemical reaction. The sum of those reactions is the
    total cell metabolism—what makes the cell alive!
•   You’ll actually visit the ecocyc database under the
    web links for this section as the last thing you do
•   Remember three things:
      1. every one of these reactions is catalyzed by a protein
      2. The amino acid sequence for those proteins are coded for in the
         DNA
      3. The world’s biggest super-computers are trying to figure out how,
         based on their unique amino acid sequence, all the different cellular
         proteins take on the particular shape they have, and control the
         particular reaction they catalyze. (You’ll also visit the Blue Gene
         IBM super-computer website in the web links for this section.)
                                                                         Larry M. Frolich, Ph.D.
                                                           Biology Department, Yavapai College
Blue Gene




                          Larry M. Frolich, Ph.D.
            Biology Department, Yavapai College
Cells—the fundamental unit of life
•   What is life?
•   Molecules of life
•   Cell as fundamental unit
•   Cell membranes and organelles
•   Cell metabolism

• Cells organized into tissues
• Types of tissues




                                                  Larry M. Frolich, Ph.D.
                                    Biology Department, Yavapai College
               What is a tissue?
•    Multi-cellular organisms are composed of
     millions and millions of cells whose metabolism
     is organized to work together.
•    A tissue is a collection of cells of the same type
     that perform a common function
•    There are 4 major tissue types in the body:
    1.   Connective
    2.   Muscular
    3.   Nervous
    4.   Epithelial


                                                          Larry M. Frolich, Ph.D.
                                            Biology Department, Yavapai College
         How many cell types?
         How many cells?
• Each class of tissue might include a
  number of different cell types. In total, our
  bodies have a few hundred different types
  of cells
• How many total cells are in our body?




                                                    Larry M. Frolich, Ph.D.
                                      Biology Department, Yavapai College
         How many cells are in an adult human? Lots. More than anyone
could count, and the bigger you are the more cells there would be. Growth is
a process of cellular reproduction, so as you grow bigger you are made up of
more cells. Following a similar logic, a larger person is larger because they
have more cells, not because their cells are larger. In fact, cell types have a
fairly uniform size across the entire human species.
         The largest and smallest cells in the human body are the gametes, or
the sex cells. The female sex cell, the oocyte, is about 35 microns in
diameter, which puts it just on the edge of being visible if you have real good
eyes. The male sex cell, spermatozoan, cell is only about 3 microns in
diameter, and therefore is the smallest cell of the human body. Various other
cell types have various other sizes within this range.
         Although no exact number can be given, the order of magnitude of
the number of cells in a human body can be approximated to 10 14 or one
hundred trillion cells.

Source: MadSci Network
http://www.madsci.org/posts/archives/mar98/889221957.An.r.html
                                                                               Larry M. Frolich, Ph.D.
                                                                 Biology Department, Yavapai College
Cells—the fundamental unit of life
    •   What is life?
    •   Molecules of life
    •   Cell as fundamental unit
    •   Cell membranes and organelles
    •   Cell metabolism
    •   Cells organized into tissues


    •Types of tissues

                                                      Larry M. Frolich, Ph.D.
                                        Biology Department, Yavapai College
           1. Epithelial tissue
•   A groups of cells that form a tight, continuous
    network
•   Lines body cavities, covers body surfaces and
    found in glands
•   Cells are anchored by a basement membrane
    on one side and free on the other side
•   Different types of epithelial cells are named
    after the appearance of cell layers and the
    shape of the cells
•   There is transitional epithelium that changes in
    appearance in response to tension

                                                       Larry M. Frolich, Ph.D.
                                         Biology Department, Yavapai College
What does epithelial tissue look
            like?




                                        Larry M. Frolich, Ph.D.
                          Biology Department, Yavapai College
       2. Connective tissue
•   Binds and supports parts of the body
•   All have specialized cells, ground substance
    and protein fibers
•   Ground substance is noncellular and ranges
    from solid to fluid
•   The ground substance and proteins fibers
    together make up the matrix of the tissue
•   There are three main types of connective
    tissue: A. fibrous , B. supportive and C. fluid

                                                      Larry M. Frolich, Ph.D.
                                        Biology Department, Yavapai College
Connective tissue holds things together
 •   Tendon, fascia
 •   Bone
 •   Cartilage
 •   Throughout body
     supporting blood
     vessels, nerves, cell
     populations (like in
     bone marrow, blood)


                                           Larry M. Frolich, Ph.D.
                             Biology Department, Yavapai College
               3. Muscle tissue
•   Allows for movement in the body

•   Made of muscle fibers/cells and
    protein fibers called actin and
    myosin

•   There are 3 types of muscle
    tissue in humans:     A.
    Skeletal
    B. Smooth
    C. Cardiac


                                                    Larry M. Frolich, Ph.D.
                                      Biology Department, Yavapai College
                 4. Nervous tissue
•   Allows for communication
    between cells through
    sensory input, integration
    of data and motor output

•   Made of 2 major cell types:
      A. Neurons—carry
      messages
      B. Neuroglia—support
      neurons



                                                Larry M. Frolich, Ph.D.
                                  Biology Department, Yavapai College
Cells—the fundamental unit of life (review)
      •   What is life?
      •   Molecules of life
      •   Cell as fundamental unit
      •   Cell membranes and organelles
      •   Cell metabolism
      •   Cells organized into tissues
      •   Types of tissues

                                               Larry M. Frolich, Ph.D.
                                 Biology Department, Yavapai College
What is Life?
• Life needs energy
• Life reproduces
• Life grows and
  develops
• Life maintains a
  stable condition—
  homeostasis
• Life responds to
  stimulus
• Life is organized
  because it has
  evolved                           Larry M. Frolich, Ph.D.
                      Biology Department, Yavapai College
The Carbon-chain Molecules of Life
MOLECULE        MADE OF         FUNCTION
Carbohydrates   Simple Sugars   Energy

Proteins        Amino Acids     Catalyze
                                reactions
Fats            Fatty Acids     Cell
                                membranes
DNA/RNA         Nucleotides     Information
                (bases)

                                                   Larry M. Frolich, Ph.D.
                                     Biology Department, Yavapai College
Cells are fundamental unit of life

• Cells are the basic
  and fundamental
  unit of life
• The first life was
  cellular life
• The Molecules of
  Life are what cells
  and all their
  internal parts are
  made up of


                                                   Larry M. Frolich, Ph.D.
                                     Biology Department, Yavapai College
WHAT CAN EUKARYOTIC CELLS                WHAT STRUCTURES ARE
DO?                                      INVOLVED?

Separate inside of cell from external    Cell Membrane
environment and control what
substances pass across membrane
Produce proteins/enzymes that            Nucleus (DNA), Ribosomes on rough
catalyze chemical reactions or control   endoplasmic reticulum
movement across membrane
Break down sugars to form energy         Mitochondria
which is stored in phosphate bonds of
ATP
Organize distribution of Molecules of    Internal membrane system and
Life (macromolecules) and ions           ―cytoskeleton‖ (ER, lysosomes,
throughout cell                          vessicles, microtubules)
Move                                     Flagella, cilia, pseudopods

                                                                           Larry M. Frolich, Ph.D.
                                                             Biology Department, Yavapai College
A cell membrane or plasma membrane separates cell
from outside world—creates ability to regulate internal
environment (homeostasis)




                                                       Larry M. Frolich, Ph.D.
                                         Biology Department, Yavapai College
           Protein synthesis
• Remember that proteins control cell
  metabolism—how and where are they
  made, or synthesized in the cell?




                                                Larry M. Frolich, Ph.D.
                                  Biology Department, Yavapai College
Ecocyc—database of complete E. coli metabolism




                                                    Larry M. Frolich, Ph.D.
                                      Biology Department, Yavapai College
               What is a tissue?
•    Multi-cellular organisms are composed of
     millions and millions of cells whose metabolism
     is organized to work together.
•    A tissue is a collection of cells of the same type
     that perform a common function
•    There are 4 major tissue types in the body:
    1.   Connective
    2.   Muscular
    3.   Nervous
    4.   Epithelial


                                                          Larry M. Frolich, Ph.D.
                                            Biology Department, Yavapai College
This initial review of life and cells is crucial!

 • Please read your book chapters, review
   the web links and get this part of the
   course.
 • We’ll come back to cells and how they
   work again and again.
 • I am aware this is a LOT of information!
 • But master this, and the rest of the course
   will seem easy.

                                                   Larry M. Frolich, Ph.D.
                                     Biology Department, Yavapai College