DNA

• Explain the structure of DNA – use the terms nucleotides, anti-parallel strands, and complementary base pairing

Two strands of the sugar-phosphate deoxyribose make up DNA. The complementary strand is 3′ and the leading strand is 5′; these strands are anti-parallel. The numbers 5′ and 3′ indicate how many carbon atoms in a deoxyribose sugar molecule a phosphate group is bound to. The sugar-phosphate strand is connected to certain nucleotides by a hydrogen bond. These bases are joined by hydrogen bonds with the only other nucleotide they may bond with, their complementary base, i.e., adenine with thymine and cytosine with guanine. The small charge on the hydrogen bonds attracts other bonds, creating the twist that gives the double helix its structure.

•  When does DNA replication occur

Since DNA replication is required for proper cell division, it will take place just before cell division. DNA replication is a process that results in a double helix of brand-new DNA. This enables the instructions to make protein to be present in every cell.

TRANSCRIPTION

The three steps are: unwinding and unzipping, complementary base pairing, and separating.

unwinding and unzipping: the stage where the helix begins to “unwind” and the DNA helicase begins to cause the two strands to “unzip” as the base-pair H-bonds are broken.

complimentary base pairing: Each template strand of DNA’s bases are paired with additional nucleotides as they enter the system. Within the nucleoplasm, these fresh nucleotides are constantly circling. The ribosomes, which are responsible for building proteins, are situated in the cytoplasm, while DNA is maintained in the nucleus for safety and protection. Both are possible destinations for mRNA, which enters the nucleus and copied the single strand. The complementary strand is constructed by the mRNA using information copied from the DNA.

joining: The new strand’s neighboring nucleotides form sugar-phosphate connections to produce the last piece of the molecule, finishing the DNA. There are two identical DNA strands left after the new molecule forms a double helix. There is a “leading” and “lagging” strand because the nucleotides are anti-parallel and must be arranged in a 3′ to 5′ order. In order to add the nucleotides, the polymerase must do it in two different methods. The polymerase follows the helicase and leading is simple. As the new DNA is being created, the polymerase on the lagging strand must move back and forth starting from the top.

Separating: The single strand template is then produced by RNA polymerase after the separation from DNA, and transcription can then begin.

TRANSLATION

Initiation: The mRNA connects to the ribosome’s “R” site via its START CODON (AUG). The initiator tRNA, or initiating codon, is identified and attached to a certain codon sequence on the mRNA.

Elongation: The mRNA sequence specifies an elongation process in which additional amino acids are added and linked together to generate polypeptides. A ribosome holds some messenger RNA during elongation and reads the codons at the P and A sites. The tRNA bases pair with the mRNA codons at the P site, while the second tRNA bases pair with the codons at the A site. The P site of the tRNA’s amino acids are transferred to the A site of the tRNA. The P site’s empty tRNA splits apart. While the amino acid chain lengthens and the tRNA at the A site moves to the P site, the amino acid chain grows.

Termination: Up until a specific codon, known as a STOP CODON, is reached, the elongation cycle will continue. Three stop codons exist: UAA, UAG, and UGA. The polypeptide chain leaves the ribosome after the last new amino acid has been added, producing protein. The ribosome now divides into its large and tiny subunits, and the mRNA is typically broken down. The endoplasmic reticulum and Golgi apparatus receive the newly synthesized protein for ultimate processing.

ANALYZING THE MODELS

– In what ways did your models accurately reflect the process?

By rearranging the components on a whiteboard, we were able to demonstrate the most crucial elements involved in the translation/transcription process and explain how they work. Because we could demonstrate each stage and note the changes that occurred throughout visually, the hands-on component of this activity helped to more accurately show Protein Synthesis.

– In what ways did your model misrepresent the process?

Compared to actual Protein Synthesis, they are less precise. Protein synthesis wouldn’t be color coded in real life. The models are also not as long or comprehensive as real-life models and only show a piece of the full process because it takes time and effort to create them considering we had to cut and tape our pieces of the activity.

– what changes could be made to the modelling activities to make them better represent the actual process?
The modelling exercise might use some adjustments to better describe the processes, among other things. Which would entail making each step dive a little deeper into the task, providing us with more information, resulting in us learning more and improving the labelling of what to do in the instructions.

Models are commonly used to communicate scientific concepts to non-scientific audiences. Do you think this is an effective way to educate the public about science? Explain why or why not.

I think that these models are an effective way to engage and educate people about scientific topics since they involve different aspects of learning. These models are useful for all kinds of learners. For example, people that learn better by listening. Since we did this model with a group of people there was a lot of talking and listening involved. If you are a visual learner, seeing where the parts of the translation/transcription are located could help one learn, along with how its color coded. If you are a hands-on learner, placing the pieces of the process in the right spot could help you learn its scientific concept. So yes, models are an effective way to educate non-scientific audiences.