NUCLEIC ACIDS & PROTEIN SYNTHESIS

_______________ are found in every living cell. Proteins are both _______________

and _______________ in nature. They build the structure of the body as well as control the chemical reactions in the body through the use of proteins called _______________.

All proteins are made of chains of _______________. Every living thing is composed of the same amino acids that we are made of. Only the arrangement of the amino acids into different proteins differs. There are _______________ different kinds of amino acids. Human muscle has a different arrangement of amino acids from cow muscle (although much of the arrangement may be similar. Many human proteins are the same in normal people (example: _______________). Others may be slightly different (example: _______________ A, B, AB, or O).

The making of these proteins by the cell is controlled by the _______________ in the chromosomes of the cell. This process is called _______________ _______________.

DNA

DNA = _______________ _______________ (the master molecule)

DNA is the major component of the chromosomes. DNA contains the instructions for the manufacturing the proteins of the body.

DNA STRUCTURE:

The structure of DNA was explained in the 1950's through the work of _______________, _______________, and _______________. Watson and Crick received the _______________ l Prize for their explanation of its structure in 1953.

_______________ = "twisted ladder"

Sides are composed of alternating _______________ and _______________ (deoxyribose).

The steps are made of pairs of nitrogen _______________.

There are only four bases: _______________, _______________, _______________, and _______________.

Adenine always pairs with _______________

Guanine always pairs with _______________.

This pairing arrangement gives DNA the ability to split apart and reproduce, with each side forming a new strand identical to the original. This process is called _______________. During replication an enzyme called _______________ breaks the weak hydrogen bonds holding the bases together in the middle. The two strands "unzip" separating into to different strands. Then new bases attach themselves to the old bases, always pairing A with T, C with G. The result is _____________________________________________.

The structure of the DNA molecule has also been called "_______________" of heredity. This is because the arrangement of the _______________ in a DNA molecule spells out a code that determines how proteins are made. Since your _______________ is made of proteins, DNA determines how your entire body is made. Since _______________ are proteins, DNA also controls all the _______________ reactions that take place in the body.

The key to this code is the arrangement of the bases up and down the strand of DNA. Three bases spell out a code that tells the cell which amino acid comes first. Then, the next three bases tell which amino acid comes next. A single protein may contain six hundred amino acids. So it may take 1800 bases to spell out the protein. Each 3-base code is called a _______________.

Here is a list of known messenger RNA codons.

	U		C		A		G
U	UUU	Phenylalanine	UCU	Serine	UAU	Tyrosine	UGU	Cysteine
	UUC	Phenylalanine	UCC	Serine	UAC	Tyrosine	UGC	Cysteine
	UUA	Leucine	UCA	Serine	UAA	Stop	UGA	Stop
	UUG	Leucine	UCG	Serine	UAG	Stop	UGG	Tryptophan
C	CUU	Leucine	CCU	Proline	CAU	Histine	CGU	Arginine
	CUC	Leucine	CCC	Proline	CAC	Histine	CGC	Arginine
	CUA	Leucine	CGA	Proline	CAA	Glutamine	CGA	Arginine
	CUG	Leucine	CCG	Proline	CAG	Glutamine	CGG	Arginine
A	AUU	Isoleucine	ACU	Threonine	AAU	Asparagine	AGU	Serine
	AUC	Isoleucine	ACC	Threonine	AAC	Asparagine	AGC	Serine
	AUA	Isoleucine	ACA	Threonine	AAA	Lysine	AGA	Arginine
	AUG	Methionine	ACG	Threonine	AAG	Lysine	AGG	Arginine
G	GUU	Valine	GCU	Alanine	GAU	Aspartic Acid	GGU	Glycine
	GUC	Valine	GCC	Alanine	GAC	Aspartic Acid	GGC	Glycine
	GUA	Valine	GCA	Alanine	GAA	Glutamic Acid	GGA	Glycine
	GUG	Valine	GCG	Alanine	GAG	Glutamic Acid	GGG	Glycine

Proteins are manufactured in the _______________ (protein factories). Therefore the information must be transferred from the _______________ in the nucleus to the ribosome. This is done by a molecule called _______________. RNA differs from DNA in that it consists of only a _______________, not a double strand. RNA also uses a different _______________ from DNA. Instead of Thymine, RNA uses a base called _______________. However, Uracil combines with Adenine just as _______________ would.

TRANSCRIPTION

The process of transferring the DNA code to a strand of RNA is called _______________.

During transcription the strand of DNA _______________ temporarily, just as it does in replication. Then RNA bases line up to pair with the DNA bases. When all of the bases are in place the messenger RNA strand breaks off and travels to the ribosome.

TRANSLATION

The process of building a protein from the mRNA code is called _______________. During this process, a second type of RNA called _______________ RNA (tRNA) is used to bring amino acids to the ribosome and assemble them in the correct order. Each tRNA molecule contains a 3-letter code (the _______________) that is the "_______________" to the mRNA code. As the tRNA molecules pair with their _______________ of the mRNA they assemble the amino acids in order.