Creation Science Winter 2008

Fall 2007 Class Videos, very large files, may take a few minutes to start playing.

1. Design Inference
2. Irreducible Complexity
3. Chance of Life
4. Evidence for a Young Earth
5. Starlight and Time
6. Radiometric Dating
7. Global Flood
8. Dinosaurs, Ice Age, Ape Men
9. Quantum Weirdness, Multiple Dimensions

An Amino Acid has a structure and shape that obeys well defined laws of chemical bonding causing it to layout precisely in according to specific angles and distances between the various atoms.

 

Some of the bonds act like a hinge allowing the molecule to swivel on a "ball bearing."

When these molecules chain together,these hinges allow the entire chain to fold up into super structures that take on quite complex forms which allow the structure to perform certain functions in accordance with its form.

Some of the proteins become transport vehicles, others become robotic machines, while still others become "keys" that can unlock other structures. The combination of various super structures of proteins eventually becomes the various tissues such as hair, muscle, skin, etc. uniquely performing their designed function.

It all starts with the geometry and arrangement of the amino acids in a specific sequence which allows the proteins to fold into particular shapes.

The following video shows a simple explanation of the translation process which is used to construct proteins from amino acids as specified by the RNA.

We are headed towards computing a probability of life coming about by random chance. But before we do that, we have been looking at the complexity of what goes on at the most fundamental levels of the cell, the smallest complete unit of life. If we are going to compute the odds like a bookie would, we must properly handicap the "teams playing the game". So, we continue this study of what it takes to make a single protein in this post.

Proteins are made inside the cell with an amazing array of robotic machines. The first process is called transcription which starts inside the nucleus of the cell where the DNA is located. A pair of fancy protein robotic machines called helicase and polymerase unwind a section of the DNA for a particular gene and create a strand of messenger RNA (mRNA in blue) utilizing spare RNA nucleotides floating around in the nucleus. An RNA molecule is essentially one half of a section of the DNA strand. This mRNA is what specifies the code for a single protein. RNA is like a copy made for temporary use, much like a contractor makes a copy of the blueprint for use in the field on a building project. Now that the mRNA is made, it moves from inside the nuclear membrane through a gateway into the cytoplasm of the cell. At the same time, two other strands of RNA are made via a similar transcription process from the DNA. These strands of RNA are folded up into a machines called transfer RNA (tRNA) and ribosomal RNA (rRNA). Together they make up another molecular device called a ribosome (green) which is responsible for building the protein.

Now that all the parts are outside the nucleus but still inside the cell proper, the process of Translation begins. The mRNA strand is divided into sets of three nucleotides called codons. The ribosome is like a reading head on a tape player and is able to feel the shape of the codons by using the anticodons of the tRNA molecules. An anticodon contains the sequence of the complementary pairs of nucleotides corresponding to the codon. Each tRNA molecule is able to carry a particular one of twenty different amino acids (in pink). One tRNA molecule is responsible for selecting the next amino acid in sequence and the second tRNA molecule is responsible for hooking the amino acid to end of the resulting polypeptide chain which becomes a protein. The rRna molecule becomes the fixed part of the ribosomal unit which slides along the entire length of the mRNA molecule stopping at the end where it completes building the protein.

The protein is then able to fold up into its functional form to begin its role in making up the parts of the body such as skin, muscle, hair or other tissues. By the way, the inside of the cell is filled with a gelatinous fluid called cytoplasm. This process would not function in water. This makes the need for a cell membrane to protect the entire process from the outside environment a critical part for the entire system to operate.

Since creation, no living cell has ever appeared anywhere on this earth that was not the product of a previous cell division. This is how life reproduces and how living organisms grow and repair themselves. In order for a cell to divide, the DNA itself must be copied. The following video shows how the complementary pairs work to make an exact duplicate of a strip of DNA. It is first split and then the corresponding nucleotide is placed on each half.

>

The rails of ladder are not show in the video but they are made of sugar phosphate molecules.

The next narrated video is a computer simulated of the replication and shows some of the amazing inter-cellular machines acting as robots to unwind then rebuild each strand of DNA. Watch for how one strand must be built in a reverse direction and how the machines handle that by pulling out a loop and working backwards.

The end result is two new DNA molecules ready for the cell to divide into two cells. Amazing! Wouldn't it be great if our engineers could build something that works as well as this does.

(Note: in the video I called the blue thing a helicase and then said it was actually a ribosome. That is incorrect, it is a helicase and a ribosome is used in another process called transcription. The lighter blue thing to the right of the helicase along with the green things are called polymerase.)

DNA is designed in such a way as to be intrinsically self-replicating. The rungs of double helix ladder are made of pairs of molecules called nucleotides. There are only four types of nucleotides and they are known by the letters A, T, G and C. There are only two possible ways one nucleotide can bond with another to make a rung. An A (adenine) can only fit with a T (thymine) and a G (guanine) can only fit with a C (cytosine). This is because of the shape of the molecules as depicted by the colored symbols on the right. The way these molecules bond is not by sharing valence electrons the way normal chemical bonding between atoms works. Rather, in organic chemistry (the chemistry of life), the shape of a molecule is the determining factor for whether bonding can occur or not. The entire pharmaceutical industry depends on this principle of organic chemistry where shape is most important.

The DNA is like a blueprint specifying how proteins are to be made. A protein is made of amino acids of which there are twenty occurring in living organisms. A protein is made by stringing together many hundreds of amino acids in what is called a polypeptide chain. The specific sequence of amino acids is what determines how the protein chain will fold up into a useful part for it destined purpose, like muscle or hair or bone. The sequence of amino acids is so important that any misplaced amino acid will render the protein ineffective. Since the DNA is the language that instructs the building of the protein, a mistake in the DNA is known as a mutation.

The language of the DNA is made up of words called codons which are a sequence of three nucleotides. This chart (click it for full size) shows how one or more codons translates to a specific amino acid. Since there are four possible nucleotides taken three at a time, that gives 3^4 or 64 possible combinations. Note that for reasons beyond the scope of this article, the U in the chart is equivalent to a T in the Nucleic alphabet. Note also that there are some codons which specify start and stop codes. Punctuation is part of the syntax of the DNA language! So a string of codons separated by start and stop codes represents a sentence in the language which specifies a single enzyme or protein. There is redundancy built into the language since in most cases more than one codon can specify a single amino acid. Perhaps this is because there is more going on here than what we understand. There is evidence that there may be multiple sets of information overlaid on top of the DNA than just protein building.

It would be like me asking you to stuff 125 miles of fishing line into a basketball without getting it tangled up. Watch the video (just over one minute, you may need to click the play button twice)