Enzymes - BartlettScience

Members of the protein family.
Called catalysts because…
They reduce activation energy and thus…
Cause chemical reactions to happen faster and thus….
Allow energy to be used from the chemical bonds
Remember…life cannot occur without the use of
Enzymes also have “thresholds” or a range in which
they can operate in…just like humans have a
“threshold” in the type of environment we can live.
The facts behind the lab
Physical Change
Solution = when one substance is dissolved
into another.
Two parts...the solute and the solvent.
Solute = whatever is being dissolved.
Solvent = the liquid.
Meat Tenderizer into water...what is the solute
and what is the solvent?
Yesterday Water was the solvent.
pH...measurement of concentration of
hydrogen atoms present in a solution.
Hydrogen is the first element on the periodic
table of elements. It is a simple element and
therefore is found in most every substance on
The pH scale Basically tells us how acidic or
basic (alkaline) a substance is.
Water ionization
Two things happen when H2O breaks apart.
Hydrogen is positively charged (H+), and Hydroxide
(OH-) is negatively charged.
An acid is a compound that RELEASES hydrogen ions
(H+) when the water molecule goes through ionization
(breaks apart)
A base is a compound that produces hydroxide ions (OH)
Think of NaOH…the base from yesterdays lab…OH is there!
PH Scale and you
The pH scale ranges from 0 – 14
Anything below 7 is acidic,
with 7 being the neutral point.
anything above 7 is a base.
Your body operates between 6 – 8 pH.
Your blood is at a 7.4. Any more “acidic” or
more “basic” you would die.
Where in your body would you find a very low
pH (an acidic environment)?
Enzyme Lab Results
Found in pineapple, harvested for use in
meat tenderizer for its ability to break apart
protein bonds.
pH levels
– Effective pH 4.0-8.0
– Optimal pH 4.5-5.5
– Ours
was 1 for the HCl, 11 for
the NaOH and 7 for the Water
Temperature Range
– Effective temperature 40-60 °C
– Optimal temperature 50-60 °C
– Deactivation
above 65 °C
temperature approx.
Temps were 17 °C in freezer,
30 °C in the fridge and 62 °C in hot
bath. Room temp was at 45 °C.
– Our
The bottom line
Water is the universal solvent.
Enzymes are necessary for life to exist but…
pH and temperature are two factors that
organisms must keep stable (homeostasis)
Like all life it has it’s limits and yesterday we
tested those limits.
If stability is not kept, enzymes stop working and
the chemical processes life depends on shut
Remember…Survival first…reproduction
Enzymes are the link between the living and the
non-living world.