Class Summary - To start class today, students took a quiz on mitosis. Then, we really broke down protein synthesis. We reviewed the process of transcription. We reviewed the following: transcription happens in the nucleus where the DNA is housed. Helicase will unzip DNA at a particular gene. RNA polymerase then assembles mRNA using free floating nucleotides in the nucleus. mRNA is created as a complementary strand to the gene that is coded for. Groups of three mRNA nucleotides is called a codon. This codon is the code for amino acids. mRNA then leaves the nucleus into the cytoplasm where translation occurs. During translation mRNA gets sandwiched between a ribosome. As the ribosome travels across the mRNA strand it joins tRNA nucleotides to the mRNA strand. Three tRNA nucleotides make an anticodon. Each anticodon carries with it an amino acid. The amino acids will then bind together to make a peptide chain; which is a protein. Then, I gave students a practice worksheet on transcription and translation. When completed, we went through the answers. Next, we did an activity to help us understand how protein synthesis works. I set the scene by describing the classroom to the students as one big cell, with the front table labeled as the nucleus. Students will start at the nucleus by picking a DNA fragment written on slips of paper and transcribing it to mRNA on their worksheets. They should not leave the nucleus table for this step. They then go to one of the ribosomes (another table or chair) to write out the corresponding tRNA sequence. Next they will search the room for the matching anti-codons on the tRNA cards on another table labeled cytoplasm. On the back of each card they will find a word (representing an amino acid) and the words should form a sentence (the protein). If the final sentence does not make sense, they have a mutation and should go back to figure out where they made a mistake.
Homework - Study for Monday's Test on Cell Structure and Function
Objectives - Students will review protein synthesis. Students will demonstrate the process of protein synthesis inside of a cell.