Enzymes

1. Members of the protein family.2. Called catalysts because…

1. They reduce activation energy and thus…2. Cause chemical reactions to happen faster and thus….3. Allow energy to be used from the chemical bonds

faster.3. Remember…life cannot occur without the use of

enzymes.1. 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.

pHacts?

● 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 earth.

● 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

– with 7 being the neutral point.● Anything below 7 is acidic,

– 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

● Bromelain ● 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 temperature approx.

above 65 °C

– Our Temps were 17 °C in freezer, 30 °C in the fridge and 62 °C in hot bath. Room temp was at 45 °C.

The bottom line

● Water is the universal solvent.● Enzymes are necessary for life to exist but…

– Like all life it has it’s limits and yesterday we tested those limits.

● pH and temperature are two factors that organisms must keep stable (homeostasis)– If stability is not kept, enzymes stop working and the

chemical processes life depends on shut down….death.

● Remember…Survival first…reproduction second. – Enzymes are the link between the living and the non-

living world.