Bio 103, Lab 5: Ongoing change at larger scales: chemical reactions and "ferments"/enzymes

Our story is that enzymes are working to keep things stable and neutral. Our experiment showed that more enzymes can better overcome the limitations of the substrate (e.g., more quickly).

Furthermore, in the pH test, the enzyme rate was highest at 7, which is neutral. In the temperature test, the enzyme rate was highest at room temperature.  So, it appears that enzymes rise more quickly/are most efficient at the "averages" of their environment. As a result, we believe that the job of enzymes is to achieve homeostasis in an organism.

<3,

Caitlin and Rachel

Elizabeth Harnett

Kaitlin Cough

What are Enzymes?

Why do they react to the environment the way they do?

When they are at the two extremes they don’t react.

They are extracted from living things and are not known outside of them.

Catalyst enzyme breaks down hydrogen peroxide.

Living things are constantly reacting to their environment…enzymes are used to help stabilize the environment…for example, hydrogen peroxide is very unstable and will blow up if there is nothing to balance it.

The enzyme is breaking down the hydrogen peroxide into water and oxygen.

So enzymes aid in the stabilization of the environment of a living organism

Basically the enzymes only work if you work, if a living organism is too hot or too cold, the enzymes are less effective and efficient. They are also less effective if the pH balance is off kilter. Everything has optimal pH and temperature levels for it to work. For this particular enzyme it seems to be around pH 7 and room temperature. For example, would these enzymes be able to balance things in the stomach, where there is a pH balance of 2?

Enzymes break things down to maintain a balance.

The more enzymes there are the faster they break something down. There’s a direct relationship between the amount of enzymes and the time it takes for them to break something down. The more enzymes there are, the faster the hydrogen peroxide was broken down, the oxygen gas was released more quickly, therefore causing the disc to rise faster.

Enzymes are found in living organisms, and also behave like living beings.

When there are more of them, under normal conditions, they are more productive, like a larger group of people working on a project.

When the temperature is manipulated, the enzymes react much like humans and animals do. When it is too hot, they become lazy and slow down, and when it is too cold they similarly slow down. But if a certain amount of heat is added to the enzyme, a gradual increase in its rate will occur until it reaches its limit of reacting under high temperatures.

If you change the pH, you are affecting the "body" of the enzyme and its ability to work normally. An enzyme at a neutral pH is able to function most efficiently. As with the bell curve of the temperature's effect on enzyme reactions, before reaching the enzyme's limit, its reaction rate will increase with an increase of pH.

Saskia Guerrier, Eurie Kim

Hypothesis
The lower the pH, the faster the "hydrogen peroxide + Catalase B" reaction; the higher the pH, the slower the "hydrogen peroxide + Catalase B" reaction.

Observations
pH2.0
trial 1: 70 secs*outlier
trial 2: 30 secs
trial 3: 30 secs
trial 4: 30 secs
AVG: 30 secs

ph7.4
trial 1: 24 secs
trial 2: 23 secs
trial 3: 19 secs
AVG: 22 secs

ph10.4
trial 1: 21 secs
trial 2: 19 secs
trial 3: 21 secs
AVG: 20.3 secs

At Wil's request, we did pH7.4 & pH10.4 over again.
pH7.4
trial 1: 15 secs
trial 2: 14 secs
trial 3: 14 secs
AVG: 14.3 secs

pH10.4
trial 1: 23 secs
trial 2: 20 secs
trial 3: 20 secs
AVG: 21 secs

Experiment Part 1: Part 1

Experiment 2: Part 3 – pH changes

Kaitlin Cough

Elizabeth Harnett

We studied the effect of different concentrations of catalysts on the dissociation of Hydrogen Peroxide. Our hypothesis was that the highest concentration of enzymes would cause the filter disc to rise the fastest. The data we collected is as follows:

There are three characteristics about enzymes that were somewhat puzzling:

1) Enzymes cause things to break down faster than they normally would.

2) In this process, enzymes do not break down themselves.

3) They break things down the most at room temperature and neutral pH's; they do not function well at extremes.

These are all characteristics of living things. The breaking down of hydrogen peroxide is like the process of consumption and digestion; looking at it this way, it makes sense that they are not broken down themselves in the process. Other living organisms also thrive in inverted "U" scales. Therefor, we think enzymes are very small living organisms.

To test this further, we could observe enzymes under a microscope and see if they appear to be improbable assemblies. Also, we could put them in an environment where there is nothing that can be broken down, and see if they are still around. If they are still present after being "starved," we would know they are not alive.

By Ruth Goodlaxson and Samar Aryani

We were responsible for part IV of the lab, concerning temperature. We tested the time it took for a filter disc, saturated in Catalase B, to rise to the top of 50 ml of hydrogen peroxide. We tested this in chilled water, water at room temperature, and hot water. Our prediction before starting the experiment was that the filter disc would rise slowly in the chilled water, faster in the room temperature, and the fastest in the hot water.

Our times for each temperature were as follows:

Chilled Water:

Trial 1: 15 seconds Trial 2: 12 seconds Trial 3: 13 seconds [average of 13 seconds]

Water in Room Temperature:

Trial 1: 11 seconds Trial 2: 11 seconds Trial 3: 11 seconds

Water in Hot Water:

Trial 1: Did not rise Trial 2: Did not rise Trial 3: Did not rise

As can be seen by our data, our prediction was wrong; the disc did not rise in the hot water.

By Ruth Goodlaxson and Samar Aryani

We were responsible for part IV of the lab, concerning temperature. We tested the time it took for a filter disc, saturated in Catalase B, to rise to the top of 50 ml of hydrogen peroxide. We tested this in chilled water, water at room temperature, and hot water. Our prediction before starting the experiment was that the filter disc would rise slowly in the chilled water, faster in the room temperature, and the fastest in the hot water.

Our times for each temperature were as follows:

Chilled Water:

Trial 1: 15 seconds Trial 2: 12 seconds Trial 3: 13 seconds [average of 13 seconds]

Water in Room Temperature:

Trial 1: 11 seconds Trial 2: 11 seconds Trial 3: 11 seconds

Water in Hot Water:

Trial 1: Did not rise Trial 2: Did not rise Trial 3: Did not rise

As can be seen by our data, our prediction was wrong; the disc did not rise in the hot water.

Kyree Harmon

Kerlyne Jean

The rate of catalase activity at pH 2.0 was 44 seconds, 45 seconds, and 44 seconds.

The rate of catalase activity at pH 7.4 was 25 seconds, 23 seconds, and 19 seconds.

The rate of catalase activity at pH 10.4 was 27 seconds, 27 seconds, and 24 seconds.

Our inital hypothesis was that the more acidic the pH, the faster the reaction would be. However, our observations are not consistent with these thoughts. Based on our observations, the more basic the pH, the faster the reaction. However, the discrepancies between neutral and the more acidic pH are not necessarily supportive of this summary and require further observation.