This demo demonstrates that yeast do cellular respiration. When sugar (glucose) and oxygen are present, yeast mitochondria will make those chemicals react and release energy as well as the products water and carbon dioxide. Bromothymol blue solution will change to yellow in the presence of carbon dioxide. If there is no more oxygen, then yeast cells will shift to fermentation.

Protein synthesis is the process that the cell goes through to make a protein from the information stored in the DNA. The video below shows a demonstration that you can do in your classroom to show how protein synthesis works. This demonstration emphasizes the following points:

1. DNA contains the information to make a specific protein.
2. The DNA is in the nucleus of the cell.
3. The DNA cannot leave the nucleus.
4. The ribosomes make the protein from the information.
5. The ribosomes are in the cytoplasm and cannot go into the nucleus.

The metaphor that I use in class is that the DNA is like a series of recipe books in the library. These books cannot be checked out/taken out of the library. The only way to get the information that is in the books out of the library is to make a copy. mRNA is the copy of the information that can leave the nucleus and go into the cytoplasm so that the ribosome can read and make the protein. Watch the video to see how it comes all together.

Teaching tips: Place the amino acids around the classroom (cytoplasm). Assign students to be specific tRNA’s. They will get the specific amino acid and bring it to the ribosome for you.



Well here is the connection between Christmas and biology that I could make. I showed the students this candy cane and told them if they could name the shape that the red stripes make they would all get one. Most of them raised their hands and when I called on one, he said "double helix". We built DNA paper models this week and they learned its shape.

Teaching and video have been around for years.  Some of us remember watching films on a projector in the classroom.  Then along came video tape.  Now we are in the era of web video.  Thanks to the internet teachers have access to more video than anytime in the past.  That's in theory of course.  In many school districts the IT department locks down the network.  YouTube, Blip.tv, and other web video are blocked.  The rationale is that students would purposefully or inadvertently access inappropriate video.  Students would get into trouble for accessing it, teachers would get into trouble for inadequate supervision, schools would get bad press, so on and so on.  Hence the rise of TeacherTube.  This site was created for teachers to upload and share video for in a safe and controlled environment, away from the "anything goes" sites like YouTube.  So why am I proposing to pull the plug on TeacherTube?

I'm not really.  It serves a purpose, but it fundamentally avoids the real problem. Districts should allow teachers access to the best tools available to enrich their classrooms and streamline their  workflow.  Blocking YouTube negates that. With TeacherTube in existence, districts feel justified in blocking basically the world's video archive.  I have experienced using TeacherTube and here are the downsides:

• Cumbersome uploading process.  Entering video information is a chore and uploading frequently fails.
• Video quality does not match YouTube.
• Ads inserted.  I know the site creators need to make money, but it's done in an extremely annoying way.
• Video choice is far less.

Here are the benefits of schools having access to Youtube:

• Easy to upload to.
• Superior video quality.
• Easy to search for video.
• Huge video library.  If I need a Bill Nye clip, a Mythbusters clip, a clip of the Hindenburg burning, anything, there is a good chance that it is there.

Is YouTube perfect?  Far from it.  My biggest complaint is in embedding videos. At the end of an embedded video there are the suggested videos that are frequently inappropriate for my students (middle school students).  This needs to be dealt with. I don't embed Youtube videos on my teacher page because of this this.  I instead upload videos to Blip.tv and link to the original download source material to avoid the suggested videos. YouTube needs to offer more control of this to its users.

My district unblocked YouTube, Blip.tv and other video sharing sites about a year and half ago and what were the results?  Students did not flock to YouTube during school time because there already is a school policy in place that instructs students to use the computer for school related purposes and not for personal entertainment. Teachers frequently walk around the computer lab room and/or classroom to monitor student activity and it works.  Imagine that.  Teachers as a result have been able to infuse into their curriculum a valuable resource.  That said, why am I writing about pulling the plug on Teacher Tube?  Our district seems to be in the minority.  When I collaborate with teachers outside the district, they frequently mention that they only have access to Teacher Tube. That is a shame. Districts please trust your teachers.  They will be responsible professionals. Don't treat them like children.

Acceleration is the change in velocity over time. Velocity changes when speed, direction, or both changes. Anyone can build a simple accelerometer. The video below shows how to build an accelerometer and how to use it.