Genetics Chapter 10 - DNA Structure and Analysis

To Serve as Genetic Material, Molecule Must Be Able To?

Replicate, Store Information, Express Information, and Allow Variation by Mutation

What is Some Indirect Evidence of DNA?

Mutagenesis: UV Light: Most Mutagenic at 260nm

Molecules Serving as Genetic Material Expected to Absorb UV at Mutagenic Wavelength, DNA Absorbs UV at 260nm, Proteins at 280nm.

What is Some Direct Evidence of DNA?

Eukaryotic DNA is Now Functional in Bacterial Cells. Ex: Insulin and Interferon Production by Bacteria

What is the Genetic Material For Some Viruses?

RNA Serves as the Genetic Material for Viruses

What is an Essential Protein Encoded in the Genomes of Most RNA-Containing Viruses?

RNA Dependent RNA Polymerase (RdRp)

Replication of Viral RNA is Dependent on ____?

RNA Replicase

What are Retroviruses?

Viruses That Replicate Unusually, RNA Serves as Template for DNA Synthesis

What is Reverse Transcriptase?

Complementary Synthesis of DNA by RNA-Dependent DNA Polymerase (For Retroviruses)

In the 30’s and 40’s, Scientists Thought ___ Was the Heredity Molecule.

Proteins

Who Discovered DNA Structure?

Watson and Crick by Using Chargaff’s Rules and Rosalind Franklin’s X-Ray Crystallography to Construct a 3D Model of DNA

What are Nucleotides?

The Building Blocks of DNA

What Do Nucleotides Consist of?

• Nitrogenous Base (Two Kinds)

• Sugar

• Phosphate Group

What are the Two Kinds of Nitrogenous Bases?

• Purines (Nine Member Ring)

• Pyrimidines (Six Member Ring)

What are the Elements For Purine Nitrogenous Base?

Adenine (A) and Guanine (G), Nine-Member Rings

What are the Elements for Pyrimidine Nitrogenous Base?

Cytosine (C), Thymine (T), and Uracil (U), Six-Member Rings

What are the Bases of DNA?

Adenine, Cytosine, Thymine, Guanine

What are the Bases of RNA?

Adenine, Cytosine, Uracil, and Guanine

RNA Contains ___ Sugar.

Ribose

DNA Contains ____ Sugar?

Deoxyribose

What Does a Nucleoside Consist of?

Contains a Nitrogenous Base, Pentose Sugar, Purine or Pyrimidine Base, and Ribose or Deoxyribose Sugar

What Does a Nucleotide Consist of?

Nucleoside With Phosphate Group Added

In a Single Strand - Each Nucleotide is Joined Together by a ___ ___ Called a ___ ____?

Covalent Bond; Phosphodiester Linkage

The Phosphodiester Linkage Bond is the DNA’s ____ ___?

Sugar-Phosphate Backbone

Nucleotides are Bonded Together by a ___ ___ to Form a Double Stranded DNA Molecule?

Hydrogen Bond

What are the Complementary Bases in DNA?

Adenine and Thymine; Guanine and Cytosine

What is the Complementary Bases in RNA?

Adenine and Uracil; Guanine and Cytosine

What are the Measurements of a DNA Molecule?

• 2.0nm Wide

• 3.4nm Distance and 360°Rotation For Every 10 Nucleotides

• 0.34nm Distance and 36°Rotation Between Each Nucleotide

What is the Major Groove of a DNA Strand?

• Where Most Proteins Bind, Like Transcription Factors

• Critical for Gene Regulation, Transcription Initiation, and DNA-Protein Regulation

What is the Minor Groove of a DNA Strand?

• Less Accessible Base Information

• Binds Certain Proteins (Histones) and Small Molecules/Drugs

• Important For DNA Structural Stability, Bending, and Chromatin Organization

Sugar and Phosphate Provides Structural Integrity of the DNA Whereas Nitrogenous Bases Encode Genetic Information. Why and How?

Nitrogenous Bases are the Coding for Genetic Information and Sugar and Phosphate are Bonded by a Strong Covalent Bond Which Provides Structural Integrity

What is A-DNA?

A Slightly More Compact Version of B-DNA Caused by High-Salt or Dehydration Conditions

What is B-DNA?

Regular DNA

What is C-DNA and P-DNA?

Less Compacted, Right-Handed Forms of DNA

What is D-DNA and E-DNA?

Forms of DNA Lacking Guanine

What is Z-DNA?

Left-Handed Double Helix Form of DNA

What is Ribosomal RNA (rRNA)?

Structural Components of Ribosomes For Protein Synthesis

What is Messenger RNA (mRNA)?

Template for Protein Synthesis and Carries Genetic Information From Gene to Ribosome

What is Transfer RNA (tRNA)?

Carries Amino Acids For Protein Synthesis

What is Telomerase RNA and RNA Primers?

Involved in DNA Replication at Chromosome Ends

What is Small Nuclear RNA (SnRNA)?

Processes mRNAs

What is Antisense RNA, microRNA, and siRNA?

Involved in Gene Regulation