Download the language of biology - Gonzaga College High School

The Language of Biology and the Language of English
An explanation of "how genes work"
Genetics links
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check out this web site for an animated tutorial on genetics. Very Cool!!
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the NHGRI talking glossary of genetics is a great place to look up terms
check out chap 10 in the book. Good diagrams and explanations; see esp. fig 10.8 and
10.9, p. 192-193.
We can compare the "language" of DNA to human language to help us understand its function:
Letters
English -- 26 letters (A - Z)
Biology -- 4 letters (A, C, G, T) called nucleotides (see how they match up)
Words or Vocabulary
English -- immense vocabulary; words from one letter to words with more than 20
letters. Changing the order of the letters changes the meaning.
Biology -- 64 "words", three letters apiece, 21 different meanings. The words are
called codons, and their meanings are known as amino acids. Changing the order
of the letters results in mutation. check out the code (alternate site)
Sentences
English -- considerable variation in length; meaning of words depends on context
to some extent. Changing the order of the words loses or changes the meaning.
Biology -- vast variations in length. Meaning of words depends almost entirely on
context.
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Stories
sentences composed of genetic codons (in the DNA) are
called genes
 explore a piece of DNA to see the typical parts of a
gene
sentences composed of amino acids are called proteins.
changing the order of the words destroys the meaning -- the
protein becomes non-functional. This is called a mutation,
and is often the cause of a disease. (more on types of
mutations)
English: sentences strung together give a single, coherent story
Biology: there are often two versions of the story, one version coming from each
parent of the organism. Figuring out version of the story gets "told" is the study of
dominant and recessive genes.
The biological story is the pattern of growth, and development; the anatomy and physiology. So
the sentences (proteins) weave together to form a story (a living organism)
now, when protein "sentences" begin to work together, we get a coherent story:
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enzymes regulate cell reactions, such as photosynthesis and respiration,
and control the sythesis (making) of other biomolecules (carbohydrates,
fats and lipids, and nucleic acids)
hormones regulate various processes in the organism, such as growth and
the menstrual cycle.
other proteins are structural molecules, such as keratin (which forms
fingernails and hair) and collagen (which is the connective tissue found in
blood vessels and cartilage, and holds the inner organs together).
there are many other functions for proteins. Together, they tell the
complex of "stories" that make up an organism.
Organization
English: generally no extraneous words or sentences
Biology: most of the "letters" are not part of the "words" or "sentences". In
humans, only about 5% of the nucleotides are part of genes. Of the other 95%,
often called junk DNA, some is involved regulating when the genes are
expressed, but most has no known function. This high percentage of "junk DNA"
results from a phenomenon known as "duplication and divergence". Check out a
representation of gene/chromosome organization.
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in addition, the stories found in biology vary from cell to cell. The story being
told in a liver cell, for example, differs significantly from the story being told in a
neural (brain) cell, despite the fact that the sequence of letters (DNA) is identical
note: this analogy was created by Dr. Al Koop, Calvin College, Grand Rapids, Michigan. Used with permission.
The expression of DNA
a comparison to transcription and translation of a book
English: The situation -- a reference book that is contained in a library must be translated into a
new language. The problem -- the translator lives outside the library and cannot get there.
The solution: library workers make a copy of the work. Making this copy is
called transcription. Then a worker carries the copy to the translator, who
translates the book.
Biology: The problem: information contained in DNA must travel outside the nucleus in order to
make a protein, but the DNA cannot leave.
Solution:
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DNA makes a copy of the appropriate "sentence". The copy
is called messenger RNA (mRNA), and the process is
called transcription. | check out an animation
mRNA travels outside the nucleus to the ribosome, where
the RNA sentence is translated into a protein sentence. This
process is called translation. The translator is a molecule
called transfer RNA (tRNA). Check out the code and tRNA
stucture here. | Animation of translation
check out this overview of the process
Note: most of the links on this page are to the Access Excellence site, operated by the National
Health Museum. Go here for information on using these images.
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Development notes