Biology

From Gene to Protein—Transcription and Translation
~Questions~
By Drs. Ingrid Waldron and Jennifer Doherty, Department of Biology, University of Pennsylvania, Copyright, 2010[1]

Introduction

1. What is a gene? State the definition, and give some examples of genes.
A gene is a section of a chromosome that provides instructions for making a protein or proteins, thereby influencing aperson’s characteristics, such as eye color, or a particular biochemical reaction.

2. What is a protein? State the definition, and give some examples of proteins.
A protein is a long train of amino acids linked together. Proteins have different functions; they can provide structure (ligaments, fingernails, hair), help in digestion (stomach enzymes), aid in movement (muscles), and play apart in our ability to see (the lens of our eyes is pure crystalline protein).

3. Complete the following table to summarize the basic characteristics of transcription and translation.

| |Original message or instructions in: |Molecule which is |Location where this takes |
| ||synthesized |place |
| | | | |
|Transcription |Nucleotide sequence in gene in DNA in chromosome |mRNA |Nucleus |
| ||A | |
|Translation |mRNA |mino acid |Ribosome |
| | | | |


4. What is hemoglobin?Hemoglobin is a protein-based component of red blood cells which is primarily responsible for transferring oxygen from the lungs to the rest of the body. Hemoglobin is actually the reason red blood cells appear red, although oxygen-rich blood is noticeably brighter than the depleted blood returning to the heart and lungs.
Transcription

5. Notice that the process of transcription is similar to theprocess of DNA replication. What are some similarities between transcription and DNA replication?
• Both begin with the help of an enzyme to get the process started.
• Both utilize base pairing rule when created
• Both are made up nucleotides which contains a nitrogenous base, a sugar and a phosphate group

6. There are also a few important differences between DNAreplication and transcription. Fill in the blanks in the following table to summarize these differences.


|DNA replication |Transcription |
|The whole chromosome is replicated. |A segment f the DNA is transcribed. |
|DNA is made.|mRNA is made. |
|DNA is double-stranded. |mRNA is double-stranded. |
|DNA polymerase is the enzyme which carries out DNA replication. |RNA polymerase is the enzyme which carries out transcription. |
|T = thymine is usedin DNA, |T = thymine is replaced |
|so A pairs with T in DNA. |by U = uracil in RNA, |
| |so A in DNA pairs with U in mRNA. |

7. Chart...