Posts Tagged ‘high school chemistry’

LEGO DNA Transcription

Wednesday, October 14th, 2015

LEGO-DNA-Transcription

When you are studying biology, why not make a LEGO DNA transcription model? This will help your high school students to internalize this process by participating in a hands-on activity to reinforce the concept.

This is a picture of DNA as it is being turned into RNA and proteins. You can look at a drawing in a textbook to see what shape you should make with the LEGOs. Start with a green LEGO base, and build up the DNA transcription process little by little.

DNA Transcription

Here is my son’s description of this process:

First a molecule called RNA Polymerase speeds down the DNA strand, unzipping the double helix and making messenger RNA, using nucleotides floating around. The RNA is basically the same as the DNA except that instead of Thymine (T), the RNA has Uracil (U).

When the RNA Polymerase reaches a special end code in the DNA, the mRNA strand is released into the cytoplasm of the cell. A ribosome forms around it. The ribosome takes transfer molecules with amino acids on them and links them to the mRNA.

Each transfer molecule has a group of three letters, called a codon, on it. The codons link up with the mRNA and, in doing so, make a protein with the amino acids they are carrying. Then the empty transfer molecules leave the mRNA and leave behind their amino acids as more take their place.

This goes on until the protein is complete. Then it goes off to a chaperone, which is a special machine for folding proteins. When the protein is folded, it is done, and it goes off to the part of the cell where it is needed.

DNA Transcription Video

If you look at the LEGO DNA transcription model at the top of this page, you can find out exactly what is happening in the model by watching this short video:

LEGO Chemistry

Monday, March 2nd, 2015

LEGO-Chemistry

My son illustrated how water dissolves salt in a solution, performing LEGO chemistry! He started with a square green base. He placed yellow and orange LEGOs on the bottom, representing Na and Cl. The Na (sodium ion) is positively charged, and the Cl (chloride ion) is negatively charged.

When placed in water, the water has a polar covalent bond, meaning that the water molecules are slightly charged. This is because the Oxygen pulls harder on the shared Hydrogen electrons, making the Oxygen side negatively charged. The two smaller Hydrogens are slightly positively charged because their electrons are being hogged by the Oxygen most of the time.

NaCl-H2O

When the table salt (NaCl) is placed into water (H20), the positively-charged Sodium atom is attracted to the negatively-charged Oxygen atom, pulling the Sodium away from the Chloride. In the same way, the negatively-charged Chloride ion is attracted to the positive end of the water molecule (the two Hydrogen atoms).

The water is dissolving the salt by breaking the Na apart from the Cl in this way. The small blue LEGOs are Oxygen atoms, and the red LEGOs are Hydrogen atoms. (In reality, he should have used tiny single LEGOs for the Hydrogen atoms, because they are way smaller than Oxygen atoms are!)

lego-chemistry-2

And there you have it: LEGO Chemistry! If you did not understand my explanation, perhaps this video will help to clear things up:

How Water Dissolves Salt

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