Genetics - Structure of the Double Helix - Lesson 14 | Don't Memorise

TL;DR

DNA molecules are made up of deoxyribose sugar, phosphate groups, and nitrogenous bases, and are arranged in a double helix structure. They are acidic in nature and can stretch up to 2 meters in length. Histone proteins help in coiling the DNA and forming the chromatin structure.

Transcript

Here’s the timeline of the history of Genetics. Beginning with the work of Gregor Mendel, we have reached this point: the experiment which proved that it is DNA which is the genetic material. Clearly, the next step would be to understand the structure of DNA. So how is this biomolecule structured? What are its constituent molecules? Let us find tha... Read More

Key Insights

• ❓ The structure of DNA was discovered in the early 1950s by Rosalind Franklin, Francis Crick, and James Watson.
• 👥 DNA is made up of deoxyribose sugar, phosphate groups, and nitrogenous bases.
• 🥹 The nitrogenous bases adenine, guanine, thymine, and cytosine form base pairs held together by hydrogen bonds.
• 👥 DNA is acidic in nature due to the presence of phosphate groups.
• ↩️ The dimensions of DNA include a diameter of 2 nanometers and a length of 3.4 nanometers per turn.
• 💁 Histone proteins help in coiling the DNA and forming the chromatin structure.
• 🤒 DNA molecules can stretch up to 2 meters in length and are coiled to fit into the tiny nucleus.

Questions & Answers

Q: When was the structure of DNA discovered?

The structure of DNA was discovered in the early 1950s by Rosalind Franklin, Francis Crick, and James Watson.

Q: What are the three major components of DNA?

The three major components of DNA are deoxyribose sugar, phosphate groups, and nitrogenous bases (adenine, guanine, thymine, and cytosine).

Q: How do the nitrogenous bases bond in DNA?

Adenine always binds with thymine, while guanine binds with cytosine. They are held together by hydrogen bonds.

Q: How long can a DNA molecule stretch?

If all the DNA from a single cell is pulled out and stretched, it would approximately be 2 meters in length.

Summary & Key Takeaways

• DNA structure was discovered in the early 1950s by Rosalind Franklin, Francis Crick, and James Watson.

• DNA is made up of deoxyribose sugar, phosphate groups, and nitrogenous bases (adenine, guanine, thymine, and cytosine).

• Adenine always bonds with thymine, while guanine bonds with cytosine. Hydrogen bonds hold the base pairs together.