DNA Structure and Function Concepts

The video tutorial explores the discovery of DNA's structure by four scientists in the 1950s. It explains the double helix model, highlighting the anti-parallel nature of nucleic acid strands and the sugar-phosphate backbone. The tutorial details the arrangement of nitrogenous bases, their perpendicular orientation, and the significance of base pair stacking. It also discusses the forces stabilizing the DNA structure, including hydrogen bonds, Vander Waals forces, and the hydrophobic effect, contributing to the overall stability of the DNA molecule.

Who were the four scientists involved in discovering the structure of DNA?

• Albert Einstein, Niels Bohr, James Watson, Francis Crick

• Isaac Newton, Charles Darwin, James Watson, Francis Crick

• Marie Curie, Louis Pasteur, James Watson, Francis Crick

• Maurice Wilkins, Rosalind Franklin, James Watson, Francis Crick

How do the two polynucleotide chains in DNA run in relation to each other?

• Perpendicular to each other

• Parallel but in opposite directions

• Parallel and in the same direction

• Randomly oriented

What is the composition of the DNA backbone?

• Lipids

• Nitrogenous bases

• Amino acids

• Sugar-phosphate groups

Where are the nitrogenous bases located in the DNA structure?

• On the exterior of the DNA molecule

• On the interior of the DNA molecule

• Randomly distributed

• Only at the ends of the DNA molecule

What is the distance between two base pairs in the DNA helix?

• 10.0 angstroms

• 5.0 angstroms

• 3.4 angstroms

• 2.0 angstroms

How many bases are there in a single turn of the DNA helix?

• 12 bases

• 8 bases

• 5 bases

• 10 bases

What is the diameter of the DNA molecule?

• 10 angstroms

• 20 angstroms

• 30 angstroms

• 40 angstroms

Which base pairs with guanine in DNA?

• Thymine

• Cytosine

• Adenine

• Uracil

What type of bond stabilizes the base pairs in DNA?

• Metallic bonds

• Hydrogen bonds

• Covalent bonds

• Ionic bonds

What effect contributes to the stability of the DNA structure in a polar environment?

• Thermal effect

• Hydrophobic effect

• Hydrophilic effect

• Magnetic effect