DNA: The Regulation of Life

Master Program of the Cell DNA – Deoxyribonucleic Acid – The molecule found in the nucleus that contains the genetic code for an organism. DNA – Deoxyribonucleic Acid – The molecule found in the nucleus that contains the genetic code for an organism.

1953 – James D. Watson and Francis H. C. Crick made the model of the DNA molecule – James D. Watson and Francis H. C. Crick made the model of the DNA molecule.

Watson and Crick figured out the model by using research done by Rosalind Franklin. Watson and Crick figured out the model by using research done by Rosalind Franklin.

Gene – A section of the DNA that has the genetic code that controls a particular trait Gene – A section of the DNA that has the genetic code that controls a particular trait

Fun Fact: If the information in your DNA were written out in English it would fill 400,000 pages of print with an average of 500 words per page. Fun Fact: If the information in your DNA were written out in English it would fill 400,000 pages of print with an average of 500 words per page.

That is about 1,000 books full of information. Even though a Chimpanzee’s DNA is 97% the same as a human’s, how much information is in that 3% difference? That is about 1,000 books full of information. Even though a Chimpanzee’s DNA is 97% the same as a human’s, how much information is in that 3% difference?

Even though it contains all this information, it consists of % of your body’s weight. Even though it contains all this information, it consists of % of your body’s weight.

Nucleus – The control center of the cell. It has to store, maintain, and retrieve DNA. Nucleus – The control center of the cell. It has to store, maintain, and retrieve DNA.

Double Helix – The twisted ladder structure of DNA Double Helix – The twisted ladder structure of DNA

Chromatin – All the DNA in the Nucleus. The double helix DNA molecule wraps around protein “spools” to take up less space (A). Chromatin – All the DNA in the Nucleus. The double helix DNA molecule wraps around protein “spools” to take up less space (A).

This is the form of DNA for most of the cell’s life. This is the form of DNA for most of the cell’s life.

Chromatid – The identical copies of the chromatin that the cell makes in s-phase of interphase. Chromatid – The identical copies of the chromatin that the cell makes in s-phase of interphase.

Chromosome – An individual chain of chromatin that is coiled in long tube-like structures (B), Chromosome – An individual chain of chromatin that is coiled in long tube-like structures (B),

… those tubes are then coiled into another tube- like structure (C), and coiled again to make up the chromosomes (D) that we see under the microscope during mitosis. … those tubes are then coiled into another tube- like structure (C), and coiled again to make up the chromosomes (D) that we see under the microscope during mitosis.

The letters A-D denote the four different coiling of the DNA to make it as compact as possible during mitosis. The letters A-D denote the four different coiling of the DNA to make it as compact as possible during mitosis.

The “legs” of the ladder are made of a phosphate “backbone” and a sugar base. Each “rung” of the ladder is made of 2 nitrogen bases. The “legs” of the ladder are made of a phosphate “backbone” and a sugar base. Each “rung” of the ladder is made of 2 nitrogen bases.

The 4 nitrogen bases are Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). The 4 nitrogen bases are Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).

Adenine (A) ALWAYS pairs with Thymine (T) Adenine (A) ALWAYS pairs with Thymine (T) Cytosine (C) ALWAYS pairs with Guanine (G) Cytosine (C) ALWAYS pairs with Guanine (G)

These bases are put together to make up the “genetic code.” Each group of three represents an amino acid. These bases are put together to make up the “genetic code.” Each group of three represents an amino acid.

Special groups indicate a start or end of the sequence. Special groups indicate a start or end of the sequence.

The Activities of DNA DNA Replication – The copying of DNA before the cell splits through mitosis. DNA Replication – The copying of DNA before the cell splits through mitosis.

This needs to be exact and if it is not, the cell will not work as efficiently or die. This needs to be exact and if it is not, the cell will not work as efficiently or die.

Steps The double helix is “unzipped” by separating the bond between the nitrogen bases (nucleotides). The double helix is “unzipped” by separating the bond between the nitrogen bases (nucleotides).

This is done by, the enzyme, DNA helicase. This is done by, the enzyme, DNA helicase.

The appropriate nitrogen bases (nucleotides) are placed in the correct pairing (A-T and C-G). The appropriate nitrogen bases (nucleotides) are placed in the correct pairing (A-T and C-G).

This is done by, the enzyme, DNA polymerace. This is done by, the enzyme, DNA polymerace.

All of the missing parts of the phosphate-sugar backbone are filled in. This is done by, the enzyme, DNA ligase. All of the missing parts of the phosphate-sugar backbone are filled in. This is done by, the enzyme, DNA ligase.

This results in two identical molecules of DNA. This results in two identical molecules of DNA.

RNA – Ribonucleic Acid – Performs various tasks that need the information on the DNA and is a single strand instead of a double strand. RNA – Ribonucleic Acid – Performs various tasks that need the information on the DNA and is a single strand instead of a double strand.

RNA uses three of the same bases, but it uses Uracil (U) instead of Thymine (T) RNA uses three of the same bases, but it uses Uracil (U) instead of Thymine (T)

RNA Transcription – The copying of a portion of DNA into a RNA form RNA Transcription – The copying of a portion of DNA into a RNA form

Steps The DNA is untwisted and “unzipped” The DNA is untwisted and “unzipped”

This allows the copy of the DNA, which is called RNA, to be made. This is done by, the enzyme, RNA polymerace. This allows the copy of the DNA, which is called RNA, to be made. This is done by, the enzyme, RNA polymerace.

The DNA is “zipped” and re-twisted. The DNA is “zipped” and re-twisted.

Types of RNA Messenger RNA (mRNA) is used to carry a particular genetic code from the DNA to a ribosome to make a protein. Messenger RNA (mRNA) is used to carry a particular genetic code from the DNA to a ribosome to make a protein.

Transfer RNA (tRNA) collects free amino acid molecules and carries them to the ribosome. Transfer RNA (tRNA) collects free amino acid molecules and carries them to the ribosome.

Ribosomal RNA (rRNA) are part of the structure of the ribosome themselves Ribosomal RNA (rRNA) are part of the structure of the ribosome themselves

Constructing a Protein When there is a need for a certain protein, the cell “looks up” how to make that protein (on the DNA) When there is a need for a certain protein, the cell “looks up” how to make that protein (on the DNA)

The cell makes a copy of this code in the form of mRNA by the process of transcription. The cell makes a copy of this code in the form of mRNA by the process of transcription.

The mRNA is transported out of the nucleus to a ribosome. The mRNA is transported out of the nucleus to a ribosome.

The mRNA is fed through the slot in the ribosome. The mRNA is fed through the slot in the ribosome.

The tRNA brings the amino acids that correspond to the code on the mRNA. The tRNA brings the amino acids that correspond to the code on the mRNA.

The ribosome links the amino acids together into a protein chain. The ribosome links the amino acids together into a protein chain.

Translation - The process of synthesizing proteins from the RNA pattern Translation - The process of synthesizing proteins from the RNA pattern

After the protein is assembled, other proteins fold it into its proper shape. After the protein is assembled, other proteins fold it into its proper shape.

The average protein is made of amino acids and can be made in about 3 minutes. Is this a random process? The average protein is made of amino acids and can be made in about 3 minutes. Is this a random process?

We know what all of the coded sequences on the DNA are (A, T, C, G), but we still do not know what they do. We know what all of the coded sequences on the DNA are (A, T, C, G), but we still do not know what they do.

Errors in Replication Mutations – Small random changes in the DNA code Mutations – Small random changes in the DNA code

Polydactyly

Albino Animals

Two-headed Cow

Webbed Toes

Skin Pigment

?????

These occur during replication when there is an extra nucleotide, a nucleotide forgotten, improper base pairing, or physical damage. These occur during replication when there is an extra nucleotide, a nucleotide forgotten, improper base pairing, or physical damage.

If this occurs in a vital gene it will cause death of the cell, but if it is not it could cause a deformity in the organism or malfunction in the cell. If this occurs in a vital gene it will cause death of the cell, but if it is not it could cause a deformity in the organism or malfunction in the cell.

What do DNA and RNA stand for? What are the names of the two scientists who made the model of DNA? Who was the scientist that provided all the information for the model? What is the difference between chromatin, chromosomes, and chromatids?

What are the names of the four nitrogen bases that make up DNA? Which ones go together? What are the steps of DNA replication. Which nitrogen base is NOT used in RNA? What replaces it? What are the steps to transcription (the making of mRNA)?

What does mRNA do? (Where does it move to and from to do this?) What does tRNA do? What are the steps for translation (the making of a protein)?