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Protein Synthesis

 

http://www.johnkyrk.com/DNAtranscription.html

http://learn.genetics.utah.edu/content/begin/dna/

 

1.     For the first link, you have a drop-down menu that lets you review other concepts in biology.  We’ll be focusing on DNA transcription and translation today.

2.     What enzyme promotes the reaction of DNA transcription?

RNA Polymerase

3.     What molecule is being copied in DNA transcription?

DNA is copied into mRNA

4.     What molecule is making the copy during DNA transcription?

MRNA

5.     By the way, what does “transcription” mean?

The process of copying DNA with MRNA

6.     Where does transcription take place?

Nucleus

7.     In what direction along the molecule does transcription take place? 5’-3’

8.     For the second link, you have two investigations.  First, go to the “Transcribe and Translate A Gene” interactive activity. Complete the activity, then answer the following questions.

9.     What is a codon? How many bases (nucleotides) make a codon? A unit of three nucleotides that when together form a unit of genetic code in a strand of RNA and DNA. 3

10.  What is the “start” codon?  What does it code for? Methionine

11.  What are the “stop” codons?  What do they code for?  UAA UGA and UAG. It codes for the stopping of translation.

12.  Where does translation take place? Cytoplasm

13.  Using both sites, name at least 4 differences between DNA and RNA molecules.

DNA contains the sugar deoxyribose, while RNA contains the sugar ribose.

DNA molecules have a uniform shape, RNA molecules have an irregular shape.

DNA nucleotides are ATCG, while RNA has AUCG

DNA stands for deoxyribonucleic acid, while RNA is ribonucleic acid.

14.  Using both sites, identify the functions of tRNA, mRNA, and rRNA.

tRNA-  Serves as transportation for amino acids that are needed for the building of proteins.

mRNA- Also known as messenger RNA, it will serve as a copy temporarily for information found in DNA when the DNA is copied during the first step of the central dogma

rRNA- Helps form the structure of the ribosomes

15.  Now watch the “What Makes A Firefly Glow?” animation so that you can see and understand the production of this protein from beginning to end.  Recall the 4 structures of the protein (review them if you’ve forgotten) and list them:

  1. Primary (Amino Acids)                   

  2. Secondary (Alpha Helix, Pleated Sheet)

  3. Tertiary (Attractions between alpha helix and pleated sheet)                    

  4. Quaternary (More than one amino acid chain)

16.  What is the enzyme responsible for making the firefly’s tail glow? Luciferase Enzyme

17.  What purpose does the glowing serve? To attract a mate and to avoid predators.

18.  On your own, discover what “lucifer” means so that you understand the name of the enzyme. To bring light.

 

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