A SpEGGtacular EGGsperiment!

The new unit we are working on is Unit 2: Cell Structure and Function.  So far, we have covered so much vocabulary in learning about all of the organelles and their important jobs inside of the cell.  We made fun analogies to remember these important organelles and their jobs, such as the nucleus is a CEO of a company because they are in charge of the entire cell, making sure it is functioning correctly.  Another organelle discussed was the cell membrane.  This organelle, I believe has one of the most important functions because they are like the security guards of a concert or building as they allow certain things in and out of the cell, and stops the things that shouldn’t enter or leave.  It is the protector of the cell!

Facilitated Diffusion

During class today, we learned about the many functions of the cell membrane and the different ways in which molecules may move in and out of the cell.  These types of molecular transport are passive transport, which includes diffusion, facilitated diffusion, and osmosis, and active transport.  We started our discussion with passive transport, which allows molecules to move freely across a cell membrane and does not require energy as molecules are moving down a concentration gradient, meaning molecules move from where there is high concentration of molecules, to where there is low concentration, until equilibrium is reach.  Osmosis specifically involves the movement of water through a cell membrane from high water to concentration to low water concentration, whereas diffusion includes other particles, with facilitated diffusion using a protein pump to push these particles across.  You can visualize facilitated diffusion as a security guard escorting someone into a building .

Active transport is just how it sounds, it is more active because it requires the use of cellular energy, ATP, to move molecules across a cell membrane.  This type of cellular transport moves molecules from areas of low concentration, to areas of high concentration, moving molecules up the concentration gradient and therefore needing to use energy to do it.  Imagine rolling a ball down a hill, from high to low.  It doesn’t take energy to roll a ball downhill, like it passive transport.  Now imagine rolling a ball up a steep hill.  You probably have to use a lot of ATP to do this!

To practice this new content, a choice activity was created for students.  According to Carol Tomlinson (2001), this form of differentiation allowing for students to have choice in the way they practice mastery of content allows for students to choose what is best fit for their learning style.  The choice activities included working a small group of 2 to 3 students and creating a skit with a cell transport analogy and specific reference to the types of cell transport, writing a rap or song, writing a children’s storybook, or creating a comic strip with text and drawings.  This was a highly successful activity as students were invested because they could choose how to master the material.  This was a great formative assessment as well, as I was able to analyze their choice activity work and depict any misunderstandings that may be occurring with one or several students.

Since students did so well with this new material, it is time for an at-home experiment that will help students visualize osmosis.  Don’t worry, it will be spEGGTacular!  The materials required and procedures are below.

Materials

·         1 large grade A egg

·         150 mL of vinegar

·         Large clear glass

Procedures

1.    Make observations of the egg prior to beginning the experiment

2.    Place the egg inside a large clear glass

3.    Pour 150 mL of water into the glass

4.    Make observations immediately

5.    Make observations after 24 hours of soaking in vinegar (take egg out of class)

6.    Make observations after 48 hours of soaking in vinegar (take egg out of glass)

For extra credit- complete the same experiment with corn syrup instead of vinegar!

After two days, draw conclusions based on your observations and the final result of the egg.  Why did this happen?  In which directions did molecules travel and why?  Use your content knowledge of cellular transport!

Tomlinson, C.A. (2001).  How to Differentiate Instruction in Mixed-Ability Classrooms.  New Jersey: Pearson.

Everyday Enzymes

As we continue with our Chemistry of Life unit, we are further building our knowledge of the importance of molecules as the building blocks of living things and today we learned about enzymes.  As we discussed, catalysts have important jobs in things as they are catalysts that speed up cellular reactions, even in our bodies like when we turn food into energy and oxygen into energy for muscles!  Enzymes work incredibly fast, and can speed up a reaction up to 10 million times faster!  What is really cool about enzymes is that they are made up of proteins and are proteins that are specific to a certain job, and are never used up!  So, once they speed up the reaction they are specific to do, they go back and do it again- they are reusable.

Lock and Key Model of Enzymes

To begin the lesson today, I showed the class a key that had a specific shape.  I then showed students various pictures of a lock and asked students if the key would work to open that specific lock.  Many students thought it was funny to even try to open a door using a key that had a different shape then the lock, and I agree!  Enzymes work just like a lock and key because a specific protein enzyme with only work with a specific substrate to speed up a certain reaction.  As with most lessons, this inquiry activity that also served as a good “hook” to get the attention of all students, worked well to make the information more visual for those that need to see the information being discussed, allowing more opportunities to connect with the new material.  We also learned that in order to be successful in the roles enzymes play, pH levels must be neutral (pH level of 7).  If the pH level is higher or lower than neutral, the enzyme will not work, similarly if the temperature is too hot or cold.  In addition, we discussed that most enzymes end in –ase, such as catalase.

One the new information was complete following the inquiry activity, a reading was completed in small collaborative groups discussing an enzyme that students encounter all the time!  The short reading is below:

Catecholase is an enzyme present in most fruits and vegetables, such as apples. It is what causes the browning of cut or bruised fruit or vegetables by catalyzing a reaction between the substrate molecule catechol and oxygen. The product of this reaction is polyphenol, which is a brown substance that gathers when fruits and vegetables are exposed to air. This color change is especially apparent in produce that has white flesh, such as apples and potatoes.

There are a few ways to prevent this enzymatic reaction. One is to submerge the fruit or vegetable in water. Water doesn’t affect the enzyme catecholase, but does reduce the availability of oxygen, part of the reactant required for the formation of polyphenol. This is why putting cut fresh potatoes in water delays browning.  Also, if the pH of fruit or vegetable is too high or low, than browning could be delayed as the enzyme does not have the conditions it needs to complete its reaction.

A few reading questions followed completion of this reading, as well as creating a hypothesis of a lab that would be completed at home.  Students were to make a hypothesis as whether a cut apple would brown faster or slower when rubbed with lemon juice, knowing that lemon juice is fairly acidic.

Now, it is the job of students to work with family members on this short experiment at home!  There has been much research completed, including that of Hill & Taylor (2004) that recognize that parent and family involvement in the educational process of students have higher levels of achievement, so this is a chance for both students and families to work together to come up with a scientific conclusion using the information provided.  Students may have to give a mini-lesson to parents of what they learned in class, but that is even better practice of the new content!  Parents/family, make sure to make a hypothesis on the students’ lab sheets!  The materials and procedures are below.

Materials:

·         1 Apple

·         1 lemon

Procedures:

1.    Slice the lemon in half

2.    Slice the apple in half

3.    Immediately rub the lemon wedge onto the open side of one half of the apple.

4.    Leave the other half of the apple flat on the table.

5.    Make observations for about 10 minutes of both slices of the apple onto a table such as the one below.

Observations
Apple Slice with Lemon Juice	Apple Slice without Lemon Juice

What might the different colors mean in terms of the enzyme, catecholase?

Now that you have completed the lab, describe your observations and explain why there were different results from each apple slice.  Make sure the use the content that we learned about enzymes!  What do your results tell you about how lemon juice may effects enzymes such as catecholase?  What happened the other apple slice?  Why did this happen?

Hill, N.E. & Taylor, L.C. (2004).  Parental School Involvement and Children's Academic Achievement.  Current Directions in Psychological Science, 13 (4).

Slippery Hydrogen Bonds!

As we continue our unit of “The Chemistry of Life,” we learned today about the amazing properties of water.  Before we started the lesson, we brainstormed as a class as many words as we could come up with that begin with the prefix co-.  You all did a great job!  Words such as cooperative, co-worker, or co-exist were among the most common.  From there, students had the task of deciding what they thought this prefix co- meant.  Based on the words that we brainstormed, students built on this knowledge to define co- as meaning “together.”  Awesome job once again!  This was a great COllaborative inquiry activity as students worked together positively to make their own learning by working with what they already knew.

How does a bug walk on water?

The reason why we needed to know what this prefix meant was because we were introducing the concept of cohesion, a property of water.  Students had already learned that a water molecule, H₂O, is made up of two hydrogen molecules, and one oxygen molecule.  But, when we see water, we don’t just see one molecule, we see millions of them together!  Well, how do these molecules work together?  Have you ever seen a bug walk on water?  Pretty cool, right?  But, why don’t they fall right through like we do when we jump in water?  We later learned that this is because of COhesion!  A property that only water can do.

Hydrogen bonds between water molecules

All I had to do was show students this word and they already knew the basics of what it most likely meant, as they took their knowledge of the prefix co- and decided it must mean the water is together.  This was great as students easily translated this basic definition to a formal scientific definition of cohesion- molecules sticking together.  From there, students were extremely invested as they have almost been the teacher for most of the lesson already!  We next learned that cohesion is when the opposite charges of a water molecule, oxygen being negatively charged and the two hydrogen atoms being positive, attract to each other, forming a strong hydrogen bond.  So, when you see a bubble of water on a plant, it is tons of hydrogen bonds forming between oxygen molecules and sticking together.  From this, students were then asked to work in small groups and justify how a bug may stand on top of water without falling in.  Several groups were correct in that the legs of a bug do not break the strong hydrogen bonds between water molecules, allowing them to stand on top!

This lesson was successful in using Vygotsky’s (1978) Zone of Proximal Development (ZPD) as the lesson was geared to what the students could do on their own, and then knowledge was pushed using collaboration and teacher mastery guidance to further learn new concepts and vocabulary.  This was seen as successful as students were engaged and motivated, while working with new information and forming deeper comprehension.  Now that students have proven they are true scientists with the simply concepts of cohesion, it is time to take this knowledge a step further by conducting a lab.  This lab is called “The Penny Lab.”  The materials and procedures are below.

Materials

·         1 Penny

·         1 pipette (provided by teacher)

·         Cup of water

·         Cup of water with soap mixed in

Procedures

1.    Place the penny face up on a flat surface

2.    Fill the pipette with the water only

3.    Drop water onto the face of the penny slowly, counting every drop

4.    Continue to count and drop water until the water spills off the penny

5.    Record the number of drops and repeat for a total of 3 trials.

6.    Once you have completed 3 trials using water only, complete the same experiment using the water and soap mixture

7.    Repeat and record for a total of 3 trials

8.    Average the trials for the two groups and draw conclusions

Make this graph in your science journal to keep your data.

Type of Water	# of Drops	# of Drops	# of Drops	Average of 3 trials
Water only
Water and Soap Mixture

Once you are completed with the trials, please conclude as to why you think the water and soap mixture might not be able to hold as much water on top of the penny.  Use your content knowledge from the lesson of hydrogen bonds and cohesion to defend you answer.

I look forward to seeing your conclusions!


Vygotsky, L. S. (1978). Mind in society:  The development of higher psychological processes.  Cambridge, MA: Harvard University Press.

Ooze…What State of Matter?!

Today in class we introduced the concept of the three states in which matter can exist- solids, liquids, and gases.  The unit we are currently in, Chemistry of Life, has discussed several topics including, the structure of atoms, how to use the periodic table to find protons, electrons, and neutrons, and now we are learning how these atoms make up the idea of matter.  This unit is extremely important within our classroom as it gives description to everything around us!  Also, all units will build onto this as atoms are the smallest piece of matter, then cells, then parts, then organs, then systems, then organisms.  During this lesson in the unit, we defined matter as “anything with mass and volume,” which includes all things we can, and even cannot, see!  The table you eat dinner on is matter, your hair is matter, your skin, even the air you breathe is made up of matter!

We began the lesson today through an inquiry activity looking at several different pieces of matter and deciding on our own what state of matter we thought they were.  Everyone did a great job of not only identifying the state of matter before learning what they were and what defines them, and justifying why you believed this.  This was a highly successful activity as many of you were able to form the definitions of the states of matter before you knew them!  The different objects we looked at were vegetable oil, rock, ice cubs, and a balloon filled with air.  Many students concluded that the vegetable oil was “liquidy” or “slippery” and the ice cube and rock were solid in their structure.  The balloon led to more of a discussion as many students stated that the balloon itself was solid, but was still flexible, but was filled with air, which is much different than what the balloon is made out of.

Three States of Matter

When we got to the class-wide discussion of what the three states of matter are, everyone deserved a pat on the back because almost every student was able to identify what they were through the activity and give good justification as to how they are different.  Through the PowerPoint and discussion, we dove into learning more about the properties of each state of matter.  Through a graphic organizer, students were given the following to be filled-in throughout the lesson:

	Shape	Molecule Movement	Volume
Solid	Definite	Rigid,  do not move easily	Definite
Liquid	Takes the shape of the container	Vibrate, move about, slide past each other	Definite
Gas	Takes the shape of the container	Move freely at high speeds	Takes the volume of the container

Many visuals were shown of how the various atoms move through the three different states of matter, including the use of the following website that creates a great visual for simulation showing that increases and decreases in temperature change matter through the three states.  The use of various images and simulations is to ensure there are several ways to work with the new content to allow all learning styles to master the material and to increase engagement during the lesson.

Through the daily exit slip, it was seen that students mastered the material of differentiating between the properties of the three states of matter through knowledge of their particle movement, and could defend various objects’ state of matter using the information, a high verb on Bloom’s taxonomy, showing high understanding of concepts.  Since there was such a great result from the lesson, it is time for students to take their learning home through a fun lab that costs only about $1.00 to complete!  Below are the materials and procedures that must be followed.

Materials needed for the "ooze" lab

The Ooze Lab!

Materials

·         Cup ·         Ziploc Bag

·         Cornstarch ·         Water

Procedures

1.    Pour about ½ cup of corn starch into a Ziploc bag.

2.    Pour water into the cornstarch and mix in the bag.

3     Put the “ooze” through the following tests

       Add color using food coloring if you want!

a.    Pour the ooze out of the bag into a cup

b.    Roll the ooze into a ball in your hand

c.    Poke the ooze with a pen

d.    Place a bean inside of the ooze and try to dig it out

Here is a video if you need more instructions and is pretty cool to see!

(www.youtube.com)

Now that you have complete the lab, it is your job to write a paragraph (at least 5-6 sentences) identifying what state of matter you believe the ooze is and why.  Make sure to use key vocabulary and concepts from the lesson to support your reasoning.  Take a picture of the ooze you made in this lab with a mobile phone and upload it to the class website for extra credit!  The purpose of this activity is to take learning from our current unit outside of the classroom with a fun and engaging lab that you can purchase materials for from the grocery store!  This is sure to be an activity that students and parents will always remember!

A Day in the Life of Mrs.Ritchie’s Scientists!

Welcome to Mrs.Ritchie’s science class at The Academies of Anacostia!  We have a fun-filled semester ahead, with many opportunities to discovering the science affecting your everyday lives and how to investigate and ask questions like a true scientist.  In order to be the most successful in the classroom, there will be expectations for students and parents, as well as myself as the teacher.  I would like to take you all on a journey explaining what students can expect in their science class this year!

Firstly, students will be required to keep a 1 1/2” binder for this class.  This binder will be their organizational tool for the entire semester, with regular binder checks to ensure students have a well-kept and up-to-date binder to check that they have the resources they need from the class to be successful.  Every week, students will get a new “Do Now Activity” (D.N.A.- get it?!) sheet to keep in their binders.  Every class that they come in, students will complete the D.N.A. to practice information learned previously in the unit, and also questions that will lead into the new discussion according to the lesson that will be conducted.  This activity will be referenced throughout the lesson to reinforce and connect the concepts to previous material.

Students working in collaborative groups during an inquiry activity.

Almost all lessons will begin with an inquiry activity.  Inquiry-based learning is seen as the most important in a science classroom.  In this type of learning, students build onto the knowledge that they already have.  So much of science is seen every day in many things that we do, and all students need to do is build onto this previous knowledge.  This has been seen by many theorists, including John Dewey (1916), to create deeper comprehension in students as they are able to connect what they already know.  Some of these inquiry activities may involve using manipulatives.  For instance, when we learn about the nervous system, before learning key vocabulary and concepts, we will first test our nervous system by working with partners and dropping rulers and seeing how quickly and what length on the ruler we catch it.  This not only engages students, but will allow students to connect the idea that the brain controls all movements in our body.  Another way we may begin a lesson through inquiry is placing students into small collaborative groups to work with others and build onto each others’ knowledge to come to a common conclusion.  These activities are highly successful as students commonly learn well through peer interaction, collaboration practices important social skills, and it allows students to take on some of the teaching and learning for themselves, creating an opportunity for students to take ownership of their learning.

Throughout any lesson, there are a variety of learning styles addressed.  As a teacher, it is important to know that no two students learn the exact same way.  As Gartner (1983) states in his theory, there are multiple intelligences and ways in which students may learn material.  It is my goal to use as many of these learning styles as possible in any single lesson to ensure ultimate mastery of content for students.  For example, students will have a hands-on experiment or inquiry activity, then be given graphic organizers differentiated for their various learning strengths while using technology such as a PowerPoint presentation through a SmartBoard in which students may interact with, students will work with partners, will have independent work time, and will be assessed for mastery of the objective to ensure understanding and for planning of the next lesson.  There is also much use of project-based learning in which students will have choice of activity to prove mastery.

Individual student data tracker

As you can see, there is much that I plan to do to ensure the ultimate learning experience for students, including a positive learning environment, and data driven classroom in which students will track their unit mastery data to ensure achievement of 80% or more on all standards covered.  Students will come away from this science class with a passion for asking questions and taking risks with the material.  It is expected that students come to class every day prepared with not only materials, but with a positive attitude, and an open-mind to learn about new things that affect their everyday lives!  This blog is meant to be a resource for both parents and students to use for extension lessons, information of upcoming lessons and activities, and to allow for communication with all!  Please visit this blog often and I am looking forward to a great semester!

Dewey, J. (1916) Democracy and Education. An introduction to the philosophy of education, New York: Free Press.

Gardner, H. (1983). Frames of Mind. New York: Basic Book Inc.