Living 20Factories by vSbWKZ2S


									Living Factories
  Unit 7 - Biotechnology
Saccharomyces cerevisiae

 Single celled
 Type of fungus
 Exist on all living
 16 chromosomes
 Hundreds of
  different species!
            Did you know?
   We may not look much like yeast or they
    like us, but many of the 6,000 genes in
    yeast have counterparts in humans!
Looking at Yeast
    Yeast as a Living Organism
   As a living organism, just like us, yeast needs
    the following to survive and flourish:

   Respiration is the process by which a living
    organism releases energy from its food
   Do you remember the
difference between aerobic
and anaerobic respiration?
         Aerobic Respiration
   Humans produce energy through aerobic

   In aerobic respiration glucose reacts with
    oxygen in the mitochondria of the cells to
    release energy.

   Carbon dioxide and water are by-products
    of the reaction.
      Aerobic Respiration

Glucose + oxygen   carbon dioxide
                   + water
                   + energy
       Anaerobic Respiration
   Anaerobic respiration occurs when oxygen
    is not available.

   In anaerobic respiration the glucose is
    only partially broken down, and lactic acid
    is produced
   Living yeast cells in the absence of oxygen
    are still able to use sugar as their source
    of food to make energy

   This is known as fermentation

   In this case ethanol (alcohol) is produced
    instead of lactic acid
      Anaerobic Respiration

Glucose           carbon dioxide
                  + ethanol
                  + energy
        Aerobic Vs. Anaerobic
   Aerobic
    -oxygen always required
    -efficient method of respiration
    -sugar completely broken down to carbon
    dioxide and water
         Aerobic Vs. Anaerobic
   Anaerobic
    -oxygen never required
    -inefficient method of respiration
    -releases a small amount of energy
    -much of the energy remains locked up in
    the molecules of the end product (e.g. the
                 Quick Quiz

   Can you sort out the following statements
    into aerobic or anaerobic respiration?

   Just fill them into your table!
 Glucose + oxygen         carbon dioxide
                          + water           Glucose reacts in
                          + energy          the mitochondra of
 Much of the                                cells
                      Inefficient method
 energy remains       of respiration
 locked up in the
 molecules of the        Sugar completely broken
 end product             down to carbon dioxide
                         and water
Only releases a
                    Glucose            carbon dioxide
small amount
                                       + ethanol
of energy
                                       + energy
  always                Oxygen             Efficient method of
  required              never              respiration
                Bread Basics!
    Bakers use two simple facts of life to create soft,
     spongy, moist bread:

1.   First, they use the fact that yeast (a single-cell fungi)
     will eat sugar:
     -from the sugar yeast creates alcohol and carbon
     dioxide gas as waste products
     -the carbon dioxide gas created by yeast is what gives
     bread its airy texture, and
     -the alcohol, which burns off during baking, leaves
     behind an important component of bread's flavor.
             Bread Basics!
2.   Second, wheat flour, if mixed with water
     and kneaded, becomes very elastic.
     -the flour-and-water mixture in bread
     becomes stretchy like a balloon because
     of a protein in wheat known as gluten
     -gluten gives bread dough the ability to
     capture the carbon dioxide produced by
     yeast in tiny flour balloons.
       How to make bread….
You will need:

1.   Flour with added salt
     and lard rubbed in to
     make dough
2.   Yeast added to warm
     sugar solution and
     allowed to grow to
     produce bubbles
3.   Mix the yeast and the
     flour together in a bowl
4. Kneading the dough
5. Leaving the mixture to rise

  Mixture left in warm place covered by damp cloth
     6. Proving the dough

Yeast releases CO2 bubbles making dough rise
            7. Baking bread

After dough rises a couple of hours in a warm place, it's ready to
go into the oven.

There, heat causes pockets of gas in the dough to expand
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