Protein Synthesis Cookies Activity

This was probably our very favorite of this unit's activities. It was fun and it just seemed to really cement the idea of how proteins are formed into the children's memories.

An overview: In this activity, each pan with cookie dough in it is like a ribosome, where the synthesis of proteins takes place. The long chain of code on your paper is a strand of mRNA that codes for a specific protein. Each cookie topping is analogous to a different amino acid. Your hand (I guess?) is like the tRNA that goes and finds the right amino acid floating around in the cytoplasm and carries it back to be placed into the amino acid chain. And, when you are done placing all the toppings in the right order, the chain is analogous to a protein that can be released into your body to build tissue or carry out various other tasks.

And more background:

A video about protein synthesis

A video about types of RNA

Now. Here are the instructions. First, pre-activity preparation. You need to make a code-breaker sheet for each child. This will show which codons (or sequences of three bases) "code" for which amino acids (represented here by the various toppings—chocolate chips, peanut butter chips, marshmallows, etc.). Besides codons for amino acids, you need a start and a stop codon. Just so the children would know them, I used the actual codons for these that our bodies use--AUG for "start," and UAG (among others) for "stop." Then I just made up the other codons. Here was our "code":

• AUG—start
• AGA—chocolate chip
• GCC—peanut butter chip
• AGC—white chocolate chip
• UGU—sprinkle of cinnamon
• CUG—sprinkle of coconut
• AAA—chocolate kiss
• CCA—peanut
• GGU—sprinkle of rainbow sprinkles
• AUU—marshmallow
• UAG—stop

Next, write out the sequence of bases for each "protein." (Remember, proteins are chains of amino acids.) I made a different protein for each child (with a shorter one for Daisy to make it a bit easier for her). I included a sequence of "nonsense" at the beginning of each protein, representative of all the RNA that doesn't code for proteins in our chromosomes. I put in some nonsense at the end, after the "stop" codon, too.

I also made an answer key for myself, listing what the finished protein should look like for each child, so I could quickly check their work. (So for example, "3 chocolate chips, white chocolate chip, sprinkle of cinnamon, peanut, marshmallow, two peanut butter chips.")

And then, of course, you need to make your cookie pizza dough, and gather a bunch of different toppings. Here's the recipe for cookie pizza. We love it.

So, to do the activity, each child starts with a small pie pan and a handful of cookie dough. Press the dough into the pan about 1/2-inch thick. (Of course, you can press your dough in circles straight onto a cookie sheet, or even make a whole cookie pizza and let each child make his protein on a different section of the pizza. It's just easier for everyone to work at once when you use separate pans.)

Then, each child should look at his section of RNA code. Have him scan the sequence until he finds the start codon (AUG in our case). Circle the start codon. Then, with a pencil, make slashes or commas between each group of three bases after the start codon. (Don't divide the bases into groups of three before finding "start," or you might make your divisions in the wrong places and get totally different amino acids than you're supposed to! This does happen sometimes with DNA or RNA—it's called frameshift and can happen if a base is wrongly inserted to or deleted from the gene.) When you get to the stop codon, stop.

The next step is just transcribing each codon into its respective amino acid. So, with our example, if you saw "AGA," you would get a chocolate chip and place it onto your cookie. Line up the amino acids in the correct order, you can curl them around in a spiral or a wavy line if they won't fit in a straight line across your cookie (and this, too, is analogous to real proteins, as each protein has a specific shape which helps it do its job). When you get to a stop codon, you are done. 

Then bake your "protein" at 350 for 8 minutes or so (for small individual cookies) or 15-20 minutes (whole cookie pizza). Remove from oven when edges are just starting to brown. Cool and eat!

We had some extra dough, so we made a full cookie pizza also. We just let each person decorate a piece however they wanted to, but you could also do your mRNA transcription on a section of the pizza if you wanted to.

Family Traits activity

This was an activity I thought of to show how different combinations of traits can produce such differing results in siblings. There are several variations of this idea online, but nothing exactly like what I wanted, so I came up with this spreadsheet for our use. It's vastly simplified from real life, of course, but it was still fun to do.

We started out with a master list of alleles, and which were dominant and which were recessive.

Then I drew about eight different "parents." If Sam hadn't been so busy, I would have had him draw them, and then we would have had something worth sharing here. But since the focus was more on individual traits than a lovely artistic whole, it worked out okay. I made the parents very exaggated-ly have their phenotypes (big nose, hair color, etc.) and then I wrote their genotypes on the page so you could tell if they were homozygous or heterozygous.

Then we put tape on coins to show D for dominant and R for recessive. (You could just say "heads is dominant" or whatever, but actually putting the letters on helped make it more clear, I thought.)

Each set of parents had six "children." I made a spreadsheet with a list of all the alleles for each child, plus a place to write the genotypes and circle the phenotypes. Then there was a large space to draw the phenotypes for each child.

To make your "family," you would go through the following steps:

1. Choose (at random) two parents from the "parents" pile.
2. Flip a coin to determine the first child's sex. (E.g., assign female to heads/"D" and male to tails/"R")
3. Check the genotypes of the parents. If either parent is homozygous dominant, write down one dominant allele for the child to inherit. If either parent is homozygous recessive, write down one recessive allele for the child. If a parent is heterozygous, flip a coin to see which allele the child will inherit. (So, if both parents are heterozygous, flip the coin twice to see which two alleles the child gets.)
4. Once the genotype for the child is determined, circle the phenotype.
5. Repeat steps 3-4 for each trait on the list.
6. Draw what the child will look like.
7. Repeat steps 2-6 for each child of these parents.

Even though it's a little bit involved, this isn't hard to do once you understand what you're doing. I had the children work in pairs so the bigs could help the littles, but everyone had fun flipping the coins and drawing the results.

Two related videos we enjoyed:

What is a gene?

Which genetic traits are dominant?

Punnett Square Cookies

Punnett Squares are fun. Cookies are even more fun. We got the idea to combine the two from this blog post.

Here are two videos that explain how to use Punnett Squares. Because we are very attached to bears after our bear unit, we also liked this Punnett Square showing how the white bears called "spirit bears" come by their white coloration.

For this activity, I just made our favorite chocolate chip cookie dough recipe, and left out the chocolate chips. Then, for the chocolate dough, I made another batch of the same dough and added 1/2 cup of cocoa to it instead of 1/2 cup of the flour. Sugar cookie dough, obviously, would work fine too, but we quite liked the flavor of these.

One of the things I liked about this activity was how well it demonstrated the idea of the dominant allele "masking" the recessive allele. If you take a ball of light dough and a ball of dark dough (representing the two forms of the gene), and mix them together (just squish them around until they are combined), you can see that the resulting phenotype is dark, just like the original dominant allele.

After trying that, though, we didn't actually mix the two alleles together. We just left both alleles showing in our Punnett squares, so we could see the genotypes and not just the phenotypes.

And when we had finished filling out the Punnett squares, we mixed the dough together somewhat randomly to make the cookies. It resulted in some nice marbling. :) Fun!

Mitosis Cupcakes

Here is a good video about Mitosis.

This was a really simple activity, but a fun review after learning about mitosis. We were inspired by this picture here. I put the children into teams (one older and one younger child together) and each team had to show each step of mitosis on a cupcake "cell". We used colored frosting in a plastic bag with the corner cut off to pipe on the yellow frosting, and we used chocolate sprinkles to make the chromosomes. (I guess the middle two steps are kind of a zoomed-in view of just the nucleus, really.)

Everyone especially liked the splitting cell in telophase. It does look especially cute, for some reason.

DNA Replication Activity/Snack

I bet someone could come up with a better version of this activity, with foods that fit together more…naturally? I felt like there were things that would go perfectly together (like, I don't know, olives and fingers :)) but I just couldn't think of what they were! Anyway, I wanted the children to demonstrate the way DNA "unzips" and replicates, so I came up with this snack/activity. 

Before you start, learn about how DNA replication works. We really liked this video showing the process.

Then, you need four different snack foods to be your "bases". They should fit together in pairs somehow. I used square pretzels and square soda crackers for one pair (Adenine and Thymine, perhaps) and elliptical wheat crackers and slices of cheese for the other pair (cytosine and guanine, say). I tried to cut little semi-circle-shapes out of one side of each piece of cheese, so the cheese and the crackers would fit together like puzzle pieces. (Just to demonstrate more visually that they were meant to fit together.) You put a bunch of each of these "bases" onto a tray to represent the bases that are floating around free inside the cell's nucleus.

Next, for each child, I made a little tray holding one "strand of DNA." It had several base pairs lined up to make a strand (or a gene, perhaps).

Then I just had each child show me what would happen as the DNA replicated. They had to "unzip" or slide the strand apart, and then find the matching bases to complete each side of the unzipped strand. When they were done, they could see how their new DNA strand was an exact copy of the original. And then, of course, they could eat it. Yum! :)

DNA structure/ Making DNA bead necklaces

We absolutely loved making these DNA models with seed beads. In fact we liked it so much that I ended up going back to the store and getting more bead colors so we could all make a bunch more of them on subsequent days. They were just fun to make! And easy enough that, once we got the hang of it, even 5-year-old Daisy was able to do it on her own. (Although, admittedly, Daisy always has been unusually good at—and had a lot of patience for—fine motor activities.) The instructions we used are here. I found I only needed to go through about three rows with the children before they could do it totally independently.

The nice thing about these models is that they are quite accurate, though simple, and they really get across the idea of the matching base pairs. And, if you accidentally pair the wrong bases—just call it a mutation! :) Sebby made quite a few mutations on purpose in his keychains, each causing a different trait ("This one made me have red eyes! This one means I have six fingers!" etc.).

Here is a great overview video that talks about the structure of DNA.

We made both keychains and necklaces out of our bead-DNA. I think the necklaces are so beautiful! The double-helix shape can be flattened if you aren't careful, but it's easily re-twisted if necessary.

To make these, you just need two colors of seed beads in size 6/0. These will make up the sugar/phosphate "backbone" of the DNA's double helix.

And you need two colors of longer bugle beads in size #3. We used the twisted bugles because they are sparkly and pretty. :) These will be your C,T, G, A bases, so before you start, decide which colors will always pair with each other:

 Then you just need some 32-gauge wire:

Then follow the step-by-step instructions here.

Happy makers. As I said, we couldn't get enough of this. It's very relaxing to sit around stringing beads and talking.

Malachi made keychains and necklaces for all his friends in his church class. So cute.

Daisy's pretty necklace

This was my favorite set of colors. I kept one of these to wear myself! I love it.

Extracting DNA from Lentils

Abe adding the cold alcohol layer

Surprisingly (to us, anyway), it's not hard to extract DNA from many types of plant and animal cells. You can find the very simple instructions here. It's pretty cool to see those long stringy white strands and realize that that stuff is actually DNA! We extracted ours from lentils, since that's what the link described. But it sounds like pretty much anything can work. And if you want to see your own DNA, you can extract some from your saliva--instructions here.

I wasn't sure if the contact solution had to be the special "protein removing" type, so we used pineapple juice for our enzymes, and that worked fine. But, based on other tutorials I've seen, the process really is not fussy--it looks like any type of contact solution will work also.

The stringy stuff floating up at the top is the DNA!

DNA and Genetics Unit Schedule and Lesson Plan

 

This was a good unit to do right before our new baby was born, because it gave us lots of chances to talk about who we really are and how much our genes determine what we are like. It was a good time to review some biology basics that we learned last time we had a baby, during our Babies Unit. And it was fun to talk about family traits (both inherited and learned), talk about baby names, tell stories about each of the other children's births, and learn some stories about our ancestors.

 

We really loved the YouTube videos by the Amoeba Sisters. They have very clear explanations of the information, and they're cute and funny too. Really well done. I've linked most of them on the specific post that's most relevant, but I'll put some of the links here as well:

 

Video about Mitosis

Video about Meiosis

Video about Mutations

Video about DNA replication

Video about DNA structure and function

Video about RNA

Video about Protein Synthesis

Video about Punnett Squares

Video about sex-linked traits

Video about the cell cycle and cancer

 

We also liked this video about Gregor Mendel and his pea plants

 

And this video about sex determination in different organisms was fascinating!

 

This movie was pretty good, about mapping individual genomes and potential cures for genetic diseases

 

Lastly, here's my Pinterest Board for our Genetics Unit.