13.2 The Structure of DNA

13.2 The Structure of DNA

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Components of DNA

• Phosphate Backbone

• Deoxyribose 5-Carbon Sugar

• Nitrogen Base (A,T,C,G)

Nucleotide

• Covalent bond between Phosphate and 5-Carbon Sugar

• Covalent bond between 5-Carbon Sugar and Nitrogen Base

Chargaff's Rule

• Complementary Base Pairing

• A bonds with T (Double H bond)

• G bonds with C (Triple H bond)

• % A = % T and % G = % C

• % A + % C = 50% = % T + % G

Rosalind Franklin

• X-ray diffraction method

• Shows a helix shape for DNA

• Likely double helix with nitrogen bases in the middle of the DNA

• Died at 37 on Cancer

• Must be alive to get Noble Prize

Watson and Crick

• 1953 Twisted Double Helix Model

• Used Franklin's Photo 51 to determine double helix shape

• Used Chargaff's Base Pairing rules to bond A-T and C-G in the middle

• Noble Prize in 1962

Multiple Choice

In organism #1 there is 29% guanine in a molecule of DNA, Determine the percent (%) _____ thymine.

• 21%

• 29%

• 42%

• 58%

Multiple Choice

In organism #1 there is 13% thymine in a molecule of DNA, Determine the percent (%) _____ cytosine.

• 13%

• 26%

• 37%

• 74%

Multiple Choice

If a DNA stand has 32 % guanine before semi conservative replication occurs, what percent thymine will each new strand have after replication? 

• 64%
• 32%
• 18%
• 36%

Multiple Choice

The percentage of A + G equals _____.

• 26%
• 50%
• 80%
• 100%

Multiple Choice

If there is 29% guanine in a section of DNA, then there is _____ thymine

• 21%
• 29%
• 42%
• 58%

Multiple Choice

Chargaff's experiments showed that the amount of A, T, G and C is the same from species to species

• True
• False

Multiple Choice

If a section of DNA has 13% thymine, then there is _____ adenine

• 13%
• 26%
• 37%
• 74%

Multiple Choice

What does DNA stand for?

• Deoxyribonucleic acid
• Denitrogenous acid
• Deribonucleic acid
• Diribonucleic acid

Multiple Choice

Three hydrogen bonds hold together which two hydrogen bases?

• A & T

• G & C

• A & C

• T & G

Multiple Choice

Which nitrogenous base correctly matches up with adenine?

• guanine

• thymine

• cytosine

Multiple Choice

Which nitrogenous base correctly matches up with guanine?

• adenine

• thymine

• cytosine

Multiple Choice

The twisted ladder shape of DNA is called a ______________?

• twisted noddle

• winding helix

• double helix

• triple helix

Multiple Choice

What sugar is found in a nucleotide of DNA?

• deoxyribose

• ribose

• trioxyribose

Multiple Choice

What is the monomer of DNA?

• amino acid

• monosaccharide

• nucleotide

• fatty acid and glycerol

Multiple Select

What are the three parts of a nucleotide?

• phosphate group

• nitrogen base

• sugar

• fatty acid

Multiple Choice

According to Chargaff's rule, Cytosine always pair with

• Adenine

• Uracil

• Thymine

• Guanine

Multiple Choice

Which of the following is a base pair?

• Adenine - Cytosine

• Cytosine - Thymine

• Deoxyribose - Cytosine

• Cytosine - Guanine

Multiple Choice

The two strands of DNA are held together by:

• Hydrogen Bonds
• Phosphodiester Bonds
• Glycolsyl Bonds
• Glycosidic Linkages

Multiple Choice

Guanine bonds with ______________.

• Adenine
• Guanine
• Cytosine
• Thymine

Multiple Choice

Cytosine always pairs with

• Adenine
• Thymine
• Uracil
• Guanine

Multiple Choice

Which of the following best describes a DNA molecule?

• double helix

• contains ribose

• made of amino acids

• contains Uracil

Multiple Choice

Which of the following best describes a DNA molecule?

• double helix

• contains ribose

• made of amino acids

• contains Uracil

Multiple Choice

How did Rosalind take pictures of the shape of DNA

• X-Ray diffraction
• X-Ray microscopy
• Scanning Electron Microscope
• Radioation diffraction

Multiple Choice

Why didn't Rosalind Franklin at least receive a part of the Nobel Prize for the discovery of DNA?

• She was deemed unworthy.
• Winners have to be alive in order to be awarded the prize
• She did not receive enough nominations.
• The award was already to be awarded to Watson, Crick and Wilkins.

Multiple Choice

What does this image show?

• Double Helical Structure of DNA
• Triple Helical Structure of DNA
• I don't know, is that a Rorschach test?
• The image is inconclusive

Multiple Choice

What is the name of this image

• Image 51

• Series 51

• Franklin's Photograph

• Photograph 51

The Double Helix DNA

• Antiparallel Strands

• Hydrogen Bonds

• Base Pairing

Multiple Choice

Identify what structure is outlined in the BLACK outline.

• Base pair

• deoxyribose sugar

• phosphate group

• hydrogen bonds

• Nucleotide

Multiple Choice

Identify what structure is outlined in the BLACK outline.

• Base pair

• deoxyribose sugar

• phosphate group

• hydrogen bonds

• Nucleotide

Multiple Choice

Identify what structure is outlined in the BLACK outline.

• Base pair

• deoxyribose sugar

• phosphate group

• hydrogen bonds

• Nucleotide

Multiple Choice

According to Chargaff's rule, Cytosine always pair with

• Adenine

• Uracil

• Thymine

• Guanine

Multiple Choice

How is the instructions for your traits carried on a DNA molecule?

• Sequence of the nitrogen bases

• In the Deoxyribose Sugar

• In the bond between the phosphate and the sugar

• In the phosphate group

Multiple Choice

Which organelle is DNA usually found in?

• cell membrane
• vacuole
• ribosome
• nucleus

Multiple Choice

Cytosine always pairs with

• Adenine
• Thymine
• Uracil
• Guanine

Multiple Choice

Which 2 molecules forms the sides (backbone) of the DNA ladder?

• deoxyribose and adenine
• deoxyribose and a hydrogen bond
• sugar and the nucleus
• deoxyribose (sugar) and phosphate

Multiple Choice

Why is DNA important?

• it is very small and very complicated
• it's in everything
• it serves as the blueprint for traits of all living things
• because we eat it every day for energy

Multiple Choice

In DNA, Adenine bonds with ______________.

• Guanine

• Thymine

• Cytosine

• Adenine

Multiple Choice

In DNA, Adenine bonds with ______________.

• Guanine

• Thymine

• Cytosine

• Adenine

Antiparallel Strands

• Semi-conservative = You can figure out pairing by only knowing one side of the strand A=T C=G

• Run in different directions to one another (Point of the sugar 5'-3')

Hydrogen Bonds

• The hydrogen bonds connect the nitrogen bases together from both sides in the middle

• Chargaff's Base Pairing Rule

• A=T use double hydrogen bonds

• C=G use triple hydrogen bonds