classroom activities
sporte | December 31, 2015"By night all cats are gray" - Miguel Cervantes in Don Quixote
I've always liked Siamese cats. Students do, too. "Why Siamese cats wear masks" is always a favorite story in genetics class. So, when I opened my January copy of The Science Teacher, I was thrilled to see an article on Siamese cat colors and proteins AND molecular genetics (1).
In the article, the authors (Todd and Kenyon) provide some background information on the enzymatic activity of tyrosinase and compare it to the catechol oxidase that causes fruit to brown, especially apples. Tyrosinase catalyzes the first step of a…
sporte | December 17, 2015Imagine a simple hike in a grassy part of South America. You hear a rattle and feel a quick stab of pain as fangs sink into your leg. Toxins in the snake venom travel through your blood vessels and penetrate your skin. If the snake is a South American rattlesnake, Crotalus terrific duressis, one of those toxins will be a phospholipase. Phospholipases attack cell and mitochondrial membranes destroying nerve and muscle function. Without quick treatment, a snakebite victim may be die or suffer permanent damage (1, 2).
The phospholipase from the South American rattlesnake is called crotoxin…
sporte | September 8, 2015We've been fans of the Molecule of the Month series by David Goodsell, for many years. Not only is Dr. Goodsell a talented artist but he writes very clear descriptions of the ways molecules like proteins, RNA, and DNA work together and function inside a cell.
To learn about proteins and their activities, I like to go directly to the Molecule of the Month page, where I can find a list of articles organized by molecule type and name. Many of these articles can also be downloaded in a PDF format.
A really nice of his articles is that he includes PDB IDs for all the structures he discusses. The…
sporte | April 11, 2015To have an effect, a molecule must bind to a receptor and trigger a signal. Studying a receptor's structure can give us insights about the way this triggering process works.
Capsaicin is a fascinating molecule that puts the "pep" into peppers. Curiously, the amount of capsaicin in a pepper is measured with a test devised in 1912 by Wilbur Scoville. Dried peppers are dissolved in alcohol, this liquid extract is diluted in water, and trained people determine the pepper's Scoville value by "tasting" the heat.
I wonder how these people are recruited. I like hot sauce but I can't imagine…
sporte | April 8, 2015National DNA Day has a fun challenge for teachers and classrooms using Pinterest. Your class can join a larger, national, effort to create a National DNA Day Pinterest board by making your own class Pinterest board on DNA, genetics, and genomics. Some possible topics are:
Things to do with DNA
DNA and health
DNA and the Arts
DNA in the News
We're really excited about the topic on DNA and the Arts!
Here's how you can make some lovely DNA Art images for your Pinterest board in Molecule World on an iPad or, if you don't have access to an iPad, you can use Cn3D.
1. Go to our DNA search at…
sporte | September 23, 2009We always see interesting creatures whenever we walk on the beach. Now, a new program from the University of Washington and the state department of Fish and Wildlife is seeking to enlist beach walkers in a community science project where they can help monitor biodiversity.
The program is called NatureMapping and it's mission is to enlist the community and schools in monitoring the health of our beaches and contributing data to a state-managed biodiversity database. If you can get to a beach, you can help survey invertebrate species and intertidal marine fish.
Two free facilitator…
sporte | May 1, 2009No more delays! BLAST away!
Time to blast. Let's see what it means for sequences to be similar.
First, we'll plan our experiment. When I think about digital biology experiments, I organize the steps in the following way:
A. Defining the question
B. Making the data sets
C. Analyzing the data sets
D. Interpreting the results
I'm going intersperse my results with a few instructions so you can repeat the things that I've done below. I've some people writing that only experts should be analyzing data. But I disagree with those who say that sequence…
sporte | April 30, 2009We'll have a blast, I promise! But there's one little thing we need to discuss first...
I want to explain why I'm going to use nucleotide sequences for the blast search. (I used protein the other day). It's not just because someone told me too, there is a solid rational reason for this.
The reason is the redundancy in the genetic code.
Okay, that probably didn't make any sense to those of you who didn't already know the answer. Here it is.
The picture above shows the human genetic code (there are at least 16 variations on this, but that's another story). Each middle cell in the table…
sporte | April 30, 2009We had a great discussion in the comments yesterday after I published my NJ trees from some of the flu sequences.
If I list all the wonderful pieces of advice that readers shared, I wouldn't have any time to do the searches, but there are a few that I want to mention before getting down to work and posting my BLAST results.
Here were some of the great suggestions and pieces of advice;
1. Do a BLAST search. Right! I can't believe I didn't do that first thing, I think the trees I got surprised me so much all sense flew out of my brain.
2. Show us the multiple alignments. Okay. I'll…
sporte | April 30, 2009Last night, the phone rang at 9:22 pm. I quickly glanced at the caller ID. Hmmm. Why is the Seattle School district calling us at this time of night?
Apparently the swine flu has come to Seattle and the school district thought we should know.
Those messages are helpful if you're a parent, but they don't tell much about the rest of the world.
Health Map is a really wonderful, user-friendly, resource for following the epidemic.
When you get to Health Map , choose Select None to clear the map.
Then select Swine Flu.
You'll see a Google map with markers representing reports. The colors show…
sporte | April 29, 2009What tells us that this new form of H1N1 is swine flu and not regular old human flu or avian flu?
If we had a lab, we might use antibodies, but when you're a digital biologist, you use a computer.
Activity 4. Picking influenza sequences and comparing them with phylogenetic trees
We can get the genome sequences, piece by piece, as I described in earlier, but the NCBI has other tools that are useful, too.
The Influenza Virus Resource will let us pick sequences, align them, and make trees so we can quickly compare the sequences to each other.
This is how I got the sequences that I wrote about…
sporte | April 28, 2009I was pretty impressed to find the swine flu genome sequences, from the cases in California and Texas, already for viewing at the NCBI.
You can get them and work them, too. It's pretty easy. Tomorrow, we'll align sequences and make trees.
Activity 3: Getting the swine flu sequence data
1. Go to the NCBI, find the Influenza Virus Resource page and follow the link to:
04/27/2009: Newest swine influenza A (H1N1) sequences.
2. You'll see a page that looks like this:
Each column heading is a name of a segment of the influenza genome. You can see there are eight of these. Each segment…
sporte | April 28, 2009I'm a big of learning from data. There are many things we can learn about swine flu and other kinds of flu by using public databases.
In digital biology activity 1, we learned about the kinds of creatures that can get flu. Personally, I'm a little skeptical about the blowfly, but...
Now, you might wonder, what kinds of flu do these different creatures get? Are they all getting H1N1, or do they get different variations? What are H and N anyway?
We can discuss all of these, but for now, lets see what kinds of flu strains infect different kinds of creatures.
Activity 2. What flu infects…
sporte | April 28, 2009Genome sequences from California and Texas isolates of the H1N1 swine flu are already available for exploration at the NCBI. Let's do a bit of digital biology and see what we can learn.
Activity 1. What kinds of animals get the flu?
For the past few years we've been worrying about avian (bird). Now, we're hearing about swine (pig) flu.
All of this news might you wonder just who gets the flu besides pigs, birds, and humans. We can find out by looking at the data.
Over the past few years, researchers have been sequencing influenza genomes and depositing those genomes in public…
sporte | March 26, 2009In which we identify unknown human proteins.
Yesterday, I wrote about using the BLOSUM 62 matrix to calculate a score for matches between two proteins. Those scores give us a good start on understanding how blastp determines whether two sequences are matching by chance or because they're more likely to be related. But that's not all there is to calculating a blast score, and there's at least one other statistic to consider as well, the E value.
It all comes down to biochemistry
The BLOSUM 62 matrix is based on the substitutions that really do or do not happen in real protein sequences. I…
sporte | March 25, 2009In which we search for Elvis, using blastp, and find out how old we would have to be to see Elvis in a Las Vegas club.
Introduction
Once you're acquainted with proteins, amino acids, and the kinds of bonds that hold proteins together, we can talk about using this information to evaluate the similarity between protein sequences. We can easily imagine that if two protein sequences are identical, then those proteins would have the same kind of activity. But what about proteins that are similar in some regions, and not others, or proteins that only share some of the same amino acids in similar…
sporte | March 21, 2009Cofactor Genomics is offering to sequence a genome for a few classes for free using Next Generation DNA Sequencing technology (either Illumina GA or via AB SOLiD).
Quoting from their site:
Cofactor will ask course organizers for a 1 page description of how their ~700Mb sequencing project could be used as an effective teaching aid in their class. We will review and choose the best entries during the month of May. Those entries will be awarded a free sequencing project including project experimental design, sample QC, library construction, sequencing, and computational analysis. Those projects…
sporte | November 30, 2008The grocery store magazine covers all say that home made gifts are big this year. So I thought, some of you might like to channel your inner Martha Stewart and make gifts with a science theme.
Reposted in honor of the holiday and the economy.
I'm here to help to you make a merry mug with one of our favorite molecules. Yep, we're talking caffeine.
1. First, we'll go to PubChem at the NCBI. It's not an exclusive (or even last) resort but there are lots of fancy molecules hanging around, just waiting to be discovered and put onto drinking containers.
2. Now, we'll look for a molecule. I'm…
sporte | November 25, 2008I just love this title! It's nerdy and cute, all at the same time.
I read about this in www.researchblogging.org and had to check out the paper and blog write up from The Beagle Project (BTW: some of you may be interested in knowing that The Beagle Project is not a blog about dogs.)
The paper describes a class where students from Marseilles University investigate the function of unidentified genes from a Global Ocean Sampling experiment. All the sequences are obtained from the environmental sequence division at the NCBI.
Students follow the procedure outlined below:
This is a great…
sporte | November 24, 2008Ebola virus has impressed me as creepy ever since I read "The Hot Zone: A Terrifying True Story some years back by Richard Preston. (I guess he has a new book, too, Panic in Level 4: Cannibals, Killer Viruses, and Other Journeys to the Edge of Science but I haven't been in airport for the past couple of weeks, so I haven't read it yet.)
Technorati Tags: blast, phylogenetic trees, Ebola, viruses
Infectious agents that cause diseases with gruesome symptoms really excite those of us with an interest in microbiology. Tara has written about this paper, too, and summarized the details.
I…