DNA & RNA Strands: 🧵

• Formed by linking nucleotides.
• Nucleotides connect with covalent bonds between their sugar and the next nucleotide's phosphate. Think of them as "glue" holding each nucleotide together.
• Fun Fact: Each strand has two ends. At these ends, either sugar or phosphate hasn't bonded with another nucleotide. It's like how a train has a front and a back carriage!

DNA Termini (Ends): 🛑

• 3′ end: Here, the possible link site is the third carbon of the sugar in the end nucleotide.
• 5′ end: This end's link spot is the phosphate linked to the fifth carbon atom of the sugar.
• Remember: No matter how long, there's always a 5′ end and a 3′ end in DNA. Imagine it like the two poles of Earth; they're always there!

DNA Polymerase's Role: 🛠️

• It's like a builder that assembles new DNA strands by putting together nucleotides that complement the template strand.
• Creates strong covalent bonds between sugar of one nucleotide and phosphate of the next. Imagine attaching two train carriages together!
• Direction Matters! 🧭 It always works 5′ to 3′, meaning the 5′ phosphate of a free nucleotide joins the 3′ end of the growing strand. It's like our one-way street rule!

Important Note: ⚠️

• DNA polymerases can add to a chain, but they can't start the process. They need a starting point, or a 3′ terminal, to which a nucleotide can be added. Think of it as needing a foundation before building a house.

What's Next?: 🧩

• The specifics of how DNA replication begins and the roles of various DNA replications will be discussed later. Stay tuned! 📺