Transcription and Translation

Learning Objectives 

Flow of Information

Each cell has many double stranded pieces of DNA called chromosomes. The DNA sequence of these chromosomes are broken up into different segments that are called genes. These genes code for the amino acid sequence of a protein.   Here  are some images and definitions to help with all the vocabulary!

Chromosome

• • • What are they made out of?  2 strands of DNA that are complementary (match each other) 
    • What information do they code for? Different stretches of the DNA sequences code for genes.
    • How do you identify a specific chromosome? Chromosomes are numbered based on which genes they code for. 
    • How many chromosomes does a cell have? Eukaryotes always have multiple chromosomes, each with different genes

Gene

• • • What are genes? These are DNA sequences that code for a specific protein's amino acid sequence
    • Where are they located? Each chromosome has many genes- found in different parts of the chromosome's DNA sequences. 

Transcription: 

• • • This is a process of copying a section of DNA (a gene) into a type of RNA called messenger RNA
    • What does this work? A series of enzymes carry out transcription. You should know the most important one: RNA Transcriptase.
    • Where does this happen? In the nucleus. 

Translation

• • • This is the process of reading the mRNA code and translating it into the correct amino acids sequence
    • What does this work? This is done by ribosomes.
    • Where does this happen? In the cytoplasm.  The ribosome might move over to the R.E.R. and feed the newly forming protein into the RER space. 

Proteins

• • • the amino acid sequence determines the amino acid side chain interactions
    • These interactions cause the folding of the protein
    • The protein folding determines the shape
    • The shape determines the function of the protein. 

Phenotype

• • • This is the appearance or function of the individual organism
    • It is determined by which proteins and which version of the protein the cells make
    • The term allele= a different version of the same protein. 
    • Example: the version of the receptor protein that leads to black/brown hair pigments being produced, vs. the version of the receptor protein that leads to red hair pigments. 

Transcription and Translation

Transcription is the process by which DNA is used as a template or instructions for making RNA. Translation is the process by which RNA is used to make the specific protein that the DNA coded for.

This video does a nice job of explaining these two processes. I have embedded comments and questions to help guide you to the important points. Keep in mind the questions you are trying to answer from this week's Study Guide.

2. Explain the relationship between DNA sequence of a gene and the traits of an organism. 

Here is the link to the unedited video.

Optional: Nice animation showing the whole process.

DNA Transcription (Basic). Links to an external site.