hypothesis of bread mould experiment

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A Simple Experiment to Grow and Study Bread Mold

Bread mold experiment is a fun science project, where one can observe the growth of a live organism on household bread! Here is a detailed guide that will help you in conducting this experiment.

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Many people tend to find mold growing on bread disgusting. But, did you know that mold is also one of nature’s cleansers , that breaks down dead organic materials and recycles these nutrients back to the soil, which makes it essential for the ecosystem?

Mold is a type of fungi, which grows on any plant or animal material. Mushrooms and toadstools are a type of fungi. Mold grows on food and other organic matter, and thus, breaks it down into slime by which it extracts nutrient for its growth. This is many times studied in school with a simple experiment.

Bread Mold Project

To study the growth of mold on bread samples every alternate day, for a course of 2 weeks.

If you are allergic to mold, then avoid performing this experiment or use mask and gloves for safety. Seek permission from your parents and teacher before you start with the experiment. Also, after you are done noting down the results of the experiment, dispose off the bags containing moldy bread safely, without opening them.

Here is a list of materials you will need to perform the experiment.

• 5 slices of bread
• 5 transparent sealable bags
• Sticky labels
• Magnifying glass
• 5 – 7 cotton swabs
• A tablespoon
• Lemon juice/water/apple juice/salt/sugar (at least two of these items are required)

Growing mold can be a simple experiment, and performed on a slice of bread. However, to make it interesting and more detailed you can work on 5 samples of breads rather than just one. So, gather the above equipment and follow the below steps.

• Take the cotton swabs and run them over areas which have dust, like under a table, bed, or basement.
• Then rub the dust from cotton swab over the first bread slice.
• Repeat steps 2 for the other four bread slices.
• Seal three bread slices inside three transparent sealable bags.
• Put sticker on the three bags, and write down using a marker on them.
• On the first sticker write “Sample #1 – Dark Closet”; on second write “Sample #2 – Refrigerator”, and on the third write “Sample #3 – Under Light”.
• So, keep the first sample in a dark closet, second in a corner of the refrigerator where it doesn’t gets disturbed, and the third one in an area of the house which is most of the time brightly lit.
• Now, take the remaining two samples. Before you seal them in the bags and mark them with sticker add one of the above mentioned five items to them. For example, on the fourth bread sample you can add some salt, while on the fifth you can add 2 tablespoons of water. Keep these two sample in a place where they don’t get disturbed.

Observations

Wear mask and gloves whenever observing the bread mold samples. Make sure you observe the five bread samples every alternate day at a fixed time of the day, say 2 pm. It is important that you observe them every alternate day without fail, and note down your observations in a table. You can note down their physical appearance like color, shape, amount of growth per day, texture, etc. Another column of your table can be observations of the mold under the magnifying glass. If you want, you can take videos or pictures of the mold every alternate day. This will help in concluding your experiment.

If you are performing this experiment at home, then you might not have access to a microscope. However, when this experiment is performed in school many times the students are asked to observe the mold under a microscope. Note down, the appearance of the mold under the microscope, this can form a part of the observation. Usually, one sees thread like structures on top of which there is a circular shape. Here is a diagram of bread mold in detail.

You will observe different conclusions for different samples. The mold which was kept in a warm, dark, and moist condition will grow the best. However, the sample that was in the refrigerator will have a slower growth. Also, substances like salt tend to slow down the growth of bread mold. Conclusion is an important part of the experiment, so make sure you read your observations carefully before you put down the appropriate conclusion of the project. Here are pictures of mold growth on different types of breads.

Further Experimentation

Once you have tried out this experiment, you can try out further experiments using different materials. You can try growing mold on different types of breads, while maintaining the same temperature. You could also try adding more moisture to the slices of the bread, or use different amounts of lemon juice and sugar on the slices. This way you can vary one element, and note down various observations of the mold growth. So, select a hypothesis and using the appropriate materials perform the experiment again. You can also consider growing mold on soft fruits. Here are pictures of mold growing on a lemon, few strawberries, and a tangerine.

Interesting Mold Facts

The above experiment will help to study bread mold in detail. Here are some fun facts about mold that will add to your knowledge.

Mold is used by various companies to make food and medicine.

Did you know that mold is added to flavor certain cheeses? You can observe blue-gray veins on a piece of blue cheese, which appear due to the mold added to it.

Lichens are formed due to an awesome partnership between fungi and algae.

There are over 10,000 species of mold!

Did you know that outdoors, mold is almost everywhere?

To prevent mold from growing on foodstuffs, the food industry spends a lot of money on refrigeration.

I hop you enjoyed reading the above facts on mold. So, gather the equipment necessary for the experiment, perform the experiment, note down the observations every alternate day, and draw the appropriate conclusion. Good luck!

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Science Project Ideas

Bread Mold Experiment

This biology experiment requires you to gather some background information before starting with the research. Once you know what the organisms called molds are, understanding the activity would be easy.

How to Do Mold Bread Experiment

A piece of bread kept under moisture and high temperature develops mold on its surface.

Materials Needed

• Slice of bread
• Plastic zipper bag
• Masking tape
• Camera (optional)
• Sprinkle water on the slice of bread.
• Put the bread in the plastic bag and zip it.
• Use the tape to secure it further.
• Write today’s date on the tape with the marker.
• Leave the bag undisturbed for 7 days in a warm place outside the house.
• Track the growth of the mold by checking the sample every day. Collect data in the notebook on the size and color of the colony. You can also take a photograph of the bread each day.
• In the end, throw away the bag with the moldy bread without consumption or inhalation near it.

You Can Also Try Out

• Instead of just 1 slice, take 3 slices of bread and mark them as A, B and C with the marker on the masking tape. Repeat the process by placing one in the refrigerator, one in a dark room and the last one in a sunny place. Observe and analyze the rate of mold growth under the different conditions of temperature and light.
• Check the results by keeping one of the variables like temperature constant for the 3 samples mentioned above but altering the type of bread in the different samples.
• Instead of adding moisture to the 3 slices as indicated in the steps above add different amounts of lemon juice or sugar to the slices. How does that affect the molding on the bread? What happens if you add salt?

For accurate measurements, you can take the help of a plastic grid to check how many squares or cm of it gets covered by the mold. While creating the lab report for your science experiment you can plot that data along the Y-axis and the no. of days along the X-axis on a graph paper.

Mold on Bread Project Video

What is happening a conclusion.

Mold is a fungus that best grows in dark, moist and warm conditions. It feeds on organic matter like bread while decomposing the same. Hence it is harmful to consume the moldy bread or even inhale the smell as mold spores could enter the body in that way. Adding salt inhibits the development whereas sugar enhances the method. Types of bread with high moisture content like rye, oat, Boston and other dark breads mold faster than the drier and denser varieties.

Some Interesting Facts

Many food industries depend on molds to produce food materials like soy sauce, country cured ham, certain types of cheese, etc. They need to know the favorable conditions for fast culture. On the other hand, there are other food industries that take measures to preserve the produce from molds. They utilize the knowledge of the unfavorable situations of infestation.

If you are planning to demonstrate molds growing on bread at a science fair, it is best to perform the experiment beforehand and exhibit the resulting samples for all to see with due explanation of the method adopted.

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Transformations in Matter and Energy Carbon TIME is an NSF-funded partnership led by Michigan State University

Decomposers | Lesson 3 - Investigating Bread Molding

• Learning Goals
• Background Information

Talk and Writing

Students conduct an investigation to explore what happens when bread molds. They use two process tools in this lesson to record their ideas: The Predictions and Planning Tool and the Evidence-Based Arguments Tool.

Guiding Question

What happens when bread molds?

Activities in this Lesson

• Activity 3.1: Predictions and Planning about Bread Molding (35 min)
• Activity 3.2: Observing Bread Molding (60 min over 2 days)
• Activity 3.3: Evidence-Based Arguments for Bread Molding (50 min)

Target Performances

Ngss performance expectations.

High School

• Chemical Reactions. HS-PS1-7. Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.
• Matter and Energy in Organisms and Ecosystems. HS-LS1-7. Use a model to illustrate that cellular respiration is a chemical process whereby the bonds of food molecules and oxygen molecules are broken and the bonds in new compounds are formed resulting in a net transfer of energy.

Middle School

• Chemical Reactions. MS-PS1-2. Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.

This lesson will be particularly helpful for students struggling to identify that mass of decaying materials is lost to the air. Students conduct an investigation with bread molding and observe an increase in CO 2 in the air using BTB. Students must explain where the carbon atoms in the CO 2 came from.

In this lesson the students return to the guiding question for the unit about how bread molds. We will consistently focus on the idea that understanding carbon-transforming processes involves answering the Three Questions:

• The Matter Movement Question: Where are molecules moving? (How do molecules move to the location of the chemical change? How do molecules move away from the location of the chemical change?)
• The Matter Change Question: How are atoms in molecules being rearranged into different molecules? (What molecules are carbon atoms in before and after the chemical change? What other molecules are involved?)
• The Energy Change Question: What is happening to energy? ( What forms of energy are involved? What energy transformations take place during the chemical change?)

Matter (the Matter Movement and Matter Change Questions). We find that even students who have learned how to balance chemical equations do not appreciate the meaning of the procedure:

• Conservation of atoms (the Matter Change Question): The numbers of atoms on the left and right side of a chemical equation have to be the same because they are THE SAME ATOMS! A chemical equation just shows how they are being rearranged into new molecules.
• Conservation of mass (the Matter Movement Question): ALL the mass of any material is in its atoms (and none of the mass is in the bonds, which are just attractive forces between atoms). So, the mass of the products is always the same as the mass of the reactants.

Energy (the Energy Change Question). Chemists, physicists, and biologists have many different conventions for describing and measuring chemical energy. We have a deeper explanation of the conventions used in Carbon TIME units and how they relate to conventions used in different scientific fields in a document called Carbon TIME Content Simplifications . Here are some key points:

• All bond energies are negative relative to individual atoms. So, during a chemical reaction, it always takes energy (the activation energy) to break bonds. Then, energy is released when new bonds are formed.
• Whether a chemical reaction releases energy or not depends on the total energy of the reactants, compared with the total energy of the products. So, energy is released when the total bond energy of the products is lower (i.e., more negative relative to individual atoms) than the energy of the reactants.
• In systems like our atmosphere, where excess oxygen is always present, the most abundant sources of chemical energy are substances that release energy when they are oxidized (e.g., substances with C-C and C-H bonds).

Our research has consistently showed that these ideas are extremely difficult for students who have not formally studied chemistry. We therefore use the convention of twist ties to identify bonds that release energy when they are oxidized.

The investigations in all units will make use of two essential tools:

• Digital balances. Students can detect movement of atoms (the Matter Movement Question) by measuring differences in mass. In this activity students will be able to observe changes in the combined system that includes both bread and mold.
• Bromothymol blue (BTB) is an indicator that changes from blue to yellow in response to high levels of CO 2 . Thus, changes in BTB can partially answer the Matter Change Question by detecting whether there is a chemical change that has CO 2 as a reactant or product.

Activity 3.1 is the Predictions and Planning Phase of the instructional model (beginning the climb up the triangle). During this phase, students record their predictions and express ideas about what happens to matter when bread molds. They use the Predictions and Planning Tool to do this.

Activity 3.2 is the Observations Phase of the instructional model (going up the triangle). During this phase, the students record the results of their bread mold investigation and try to identify patterns in their data and observations. The important practices students focus on in this activity are 1) making measurements and observations, 2) recording their data and evidence, and 3) reaching consensus about patterns in results. They use the Observations Worksheet and Class Results Poster to do this.

Activity 3.3 the Evidence-Based Arguments Phase of the instructional model (going up the triangle). During this phase, the students review the data and observations from their investigation of bread molding and develop arguments for what happened during the investigation. In this phase, they also identify unanswered questions: at this point they have collected data and observations about macroscopic scale changes (BTB color change and mass change), but they do not have an argument for what is happening at the atomic-molecular scale (unless they are able to make predictions based on their experiences from the Animals and/or Plants units). They use the Evidence-Based Arguments Tool to record their arguments at this phase.

Key Carbon-Transforming Processes: Digestion, Biosynthesis, and Cellular Respiration

At this stage in the unit, students will complete the inquiry and application sequences for bread molding—they go both up and down the triangle. This means that they will go through the Predictions and Planning Phase, the Observations Phase, and the Evidence-Based Arguments Phase in one lesson. The tables below show specific talk and writing goals for these phases of the unit.