Ch. 11 Nucleic Acid

Myoglobin

- protein that transport oxygen to muscles through rectangular hyperbola

A polypeptide of 153 amino acid residues

Hemoglobin

Protein that transports oxygen from the lungs to the body and carbon dioxide to exhale

Through sigmoidal transport

2 alpha chains- 141 amino acid residue

2 beta chains- 146 amino acid residue

The Hills Constant

The binding kinetics of Myoglobin and Hemoglobin

What is n for myoglobin and hemoglobin ?

Myoglobin: n=1 because of rectangular hyperbola

Hemoglobin: n= 2.8 because of sigmoidal

enzymes that chop up your DNA

Type 2 restriction endonucleases

Separates nucleic acid fragments that differ from one another in length

Gel electrophoresis

Reaction that copies DNA strand in complementary fashion to form a new second strand (adds nucleotides in 5’-3’ directions to the 3’end)

DNA Polymerase reaction

The unzipping of DNA to get 2 daughter strands (identical)

DNA replication

Oligonucleotide that pairs with the 3’-end of the template molecule to form dsDNA

Primer

A template DNA base-paired with a complementary primer is copied by DNA polymerase in the presence of dATP, dCTP, dGTP, dTTP

Primer extension

What are the colors for the dideoxynucleotide analogs that determine the sequence of the DNA:

1. DdATP

2. DdCTP

3. DdGTP

4. DdTTP

1. DdATP- orange

2. DdCTP- blue

3. DdGTP- green

4. DdTTP- red

The stability of the DNA double helix is due to….

Hydrogen bonds between base pairs

Mutual repulsion of phosphate groups that makes them both stable on the helix exterior

Electrostatic interactions

What are the canonical base pairs ?

Adenine and Thymine (share 2 H bonds)

Guanine and Cytosine (/share 3 H bonds/more stable)

The rotation of one base pair relative to the next, around the axis of the double helix

Helical Twist

Comparison of A, B, Z DNA

A: right handed- short and broad, 2.3 A, 11bp

B: right handed- long and thin, 3.32 A, 10bp

Z: left handed- longest and thinnest, 3.8 A, 12bp

What methylation switches genes off?

Cytosine

Name the three intercalating agents

1. Ethidium bromide

2. Acridine orange

3. Actinomysin D

If the strands of DNA are under wound or overwound, what happens ?

The double stranded circular DNA forms supercoils

How long is the human DNA?

2 meters

Protein spools

Nucleosomes

The association of DNA with protein (histone and nonhistone chromosomal proteins)

Chromatin

Why do RNA molecules have a greater number of conformational possibilities ?

They share single stranded and have 6-7 degrees of freedom per nucleotide unit

How do complementary sequences in RNA join ?

Intrastrand base pairing

When the base pairing is imperfect what can form ?

Hairpin stem-loop structures

What shape is phenylalanine tRNA?

L-shaped