Nucleic Acids (Part 4)

5’ end to the 3’ end

Codons are written from the _____________ of the mRNA molecule.

Order of Amino Acids

mRNA contains the sequence of codons that determine the ___________ in the protein.

tRNAs

Individual ________ bring specific amino acids to the peptide chain.

Binding Sites

rRNA contains ____________ that provides the platform on which protein synthesis occurs.

Initiation, Elongation, Termination

The three main parts of Translation are ________________

ACA

Codon of Threonine

GCG

Codon of Alanine

AGA

Codon of Arginine

Initiation

___________ begins with mRNA binding to the ribosome.

Codon AUG

In Initiation, the tRNA brings the first amino acid, always at _____________

AUG

Codon of Methionine

Elongation

______________ proceeds as the next tRNA molecule delivers the next amino acid, and a peptide bond forms between the two amino acids.

Stop Codons

UAA, UAG, UGA

Termination

Translation continues until a stop codon (UAA, UAG, UGA) is reached, which is called ____________; the completed protein is released.

Mutation

A _______ is a change in the nucleotide sequence in a molecule of DNA.

Mutagens

Some mutations are random, while others are caused by _________.

Point Mutation

A _________ is the substitution of one nucleotide for another.

Deletion Mutation

A __________ occurs when one or more nucleotides are lost from a DNA molecule.

Insertion Mutation

An _________ occurs when one or more nucleotides are added to a DNA molecule.

Silent Mutation

A __________ has a negligible effect to the organism, because the resulting amino acid is identical. This mutation has no effect.

One Different Amino Acid

A mutation that produces a protein with __________ usually has a small to moderate effect on the protein overall.

Sickle Cell Anemia

Some proteins, such as hemoglobin, substitution of just one amino acid can result in the fatal disease __________.

Stop Codon

If a mutation causes a big change, like producing a ________, the remainder of the protein will not be synthesized, which can have catastrophic results.

Genetic Disease

When a mutation causes a protein deficiency or defective protein synthesis and this mutation is passed through generations, it is a ___________.

Cystic Fibrosis

The effects are extremely thick lung mucus and low pancreatic secretions. ___________ results from defective cyctic fibrosis transmembrane conductance regulator (CFTR).

Galactosemia

___________ results from a deficiency of an enzyme needed for galactose metabolism and can cause mental retardation.

Tay-Sachs Disease

Mental retardation: Caused by a defective Hexosaminidase A enzyme

Sickle Cell Anemia

Occlusion and Inflammation of blood capillaries, caused by defective hemoglobin; Anemia

Phenylketonuria

Mental retardation; Caused by a deficiency of the enzyme phenylalanine hydroxylase needed to convert the amino acid Phenylalanine to Tyrosine

Galactosemia

Mental retardation; Caused by a deficiency of an enzyme needed for galactose metabolism

Huntington’s Disease

Progressive physical disability: Caused by a defect in the gene that codes for the Htt protein, resulting in degeneration in the neurons in certain areas of the brain.

Recombinant DNA

___________ is synthetic DNA that contains segments from more than one source.

DNA molecule, Enzyme, Gene from a second organism

Three key elements are needed to form recombinant DNA:

1. A ___________ into which a new DNA segment will be inserted.

2. An ___________ that cleaves DNA at specific locations.

3. A ____________ that will be inserted into the original DNA molecule.

Restriction Endonuclease (EcoRI)

In Recombinant DNA, first is the bacterial plasmid DNA is cut by the _____________, which cuts in a specific place.

Sticky Ends

Double strand of linear plasmid DNA with two ends ready to bond, called _________.

Human DNA

Then, a second sample of ___________ is cut with the same EcoRI.

Complimentary to the Plasmid DNA

This forms human DNA segments with sticky ends that are ____________.

DNA Ligase Enzyme

Combining the two pieces of DNA with __________ forms DNA containing the new segment.

Additional Segment

This DNA chain is slightly larger because of its __________.