4.2 DNA Structure

Tip: When doing the Practice or Test mode, adjust the settings to *answer with definitions.* | Tags: DNA, DNA Structure, Genes

What term refers to one large molecule of DNA? (C in the image)

Chromosome

What term refers to a small region of DNA? (D in the image)

Gene

What are the three parts of a nucleotide?

Phosphate, Sugar, Nitrogen base

Which letter refers to a “backbone”?

A

Which letter refers to the “base pairs”?

C

What letter refers to the “sugar” region of the molecule?

A

What letter refers to the “phosphate” region of the molecule?

C

What letter refers to the “nitrogen base” region of the molecule?

D

What letter refers to the “covalent bond”, and is it a strong or weak bond?

B, strong

What letter refers to the “hydrogen bond”, and is it a strong or weak bond?

E, weak

How many “backbones” does a DNA molecule have and what subunits does it consist of?

2 backbones, phosphate and sugar

What type of bond holds together the opposite strands?

Hydrogen bond

What type of bond holds together the nucleotides within one strand?

Covalent bond

What is the name for the “monomer” of a DNA molecule?

Nucleotide

Which scientist(s) used physical models and theory to solve the puzzle of DNA’s structure?

James WATSON and Francis CRICK

Which scientist(s) used X-ray crystallography to photograph the structure of DNA?

Rosalind FRANKLIN

Which scientist(s) confirmed that DNA is a double helix, and not a triple helix as previously thought?

Rosalind FRANKLIN

Who stole research data from another scientist and used it, without giving credit, to receive recognition and the Nobel Peace Prize for solving the DNA puzzle?

James WATSON and Francis CRICK

Who died from cancer, likely due to continuous X-ray exposure, and did not receive the Nobel Peace Prize for their contribution to solving the DNA puzzle?

Rosalind FRANKLIN

Which scientist(s) collected data that revealed the “base-pair rule”?

Erwin CHARGAFF

What does the base-pair rule state about the nitrogen base bonding pattern?

Single ring - Double rings

What bases pair together?

A - T and C - G

Which term accurately describes the orientation of the two strands of a DNA molecule and why?

Anti-parallel because they run side by side in opposite directions

If the phosphate group in the left strand of a DNA molecule points UP, what direction does it point in the right strand?

DOWN, as the strands are anti-parallel.

Which directionality of a nucleotide is the 5’ end?

The phosphate end

Which directionality of a nucleotide is the 3’ end?

The bottom of the sugar

Which letter corresponds with the 5’ carbon?

A

Which letter corresponds with the 3’ carbon?

C

If 20% of a DNA molecule consists of adenine nitrogen bases, what percent of the molecule consists of thymine?

20%

If 20% of a DNA molecule consists of adenine nitrogen bases, what percent of the molecule consists of cytosine?

30%

True or False: All of your body cells contain the same DNA.

True