Biology 12 Revised Presentation – Jan 2018 Student DNA Replication Biology 12 Revised Presentation – Jan 2018 Student

DNA Structure - Recap

Recap

Recap

What does this look like in the cell?

DNA – Recap

When does DNA replication in the cell happen?

happens

Steps of DNA Replication When the DNA helix ___________, it exposes the nitrogenous bases For extra information / notes on this process, watch DNA Structure & Replication, Crash Course Biology video #10 (from 8:52 onwards) https://www.youtube.com/watch?v=8kK2zwjRV0M&index=3&list=PLLhLoKibENnnXugdb dQKa80W6Fz85gBeL

Steps of DNA Replication Step 2: Complementary Base Pairing -First, RNA _________ are complementarily paired to the DNA parent strands -Next, free floating ____________ (always present in the nucleus) move in and complementarily pair up with the exposed nitrogenous bases - Adenine always binds with Thymine, Guanine always pairs with _________ . -DNA _________- is used to place and join the new nucleotides to DNA parent strands

Steps of DNA Replication Step 2: Complementary Base Pairing (continued) -DNA polymerase can only read the template DNA in a 3’ to 5’ ________ -DNA can only make a new complementary strand in a 5’ to 3’ direction. -Since DNA strands are oriented in an anti-parallel configuration, new DNA strands are made in two ________ directions.

Steps of DNA Replication Step 2: Complementary Base Pairing (continued) -The leading strand makes a new strand of DNA in a 5’ to 3’ direction (it follows the DNA helicase enzyme, moving up the old or parent strand in a 3’ to 5’ direction.) -The _________ strand makes a new strand of DNA in pieces called Okazaki fragments

Steps of DNA Replication Step 3: Nucleotide Bonding -The new strands of DNA are ___________ up. DNA ligase seals the sugar-____________ backbones and Okazaki fragments of the new daughter strands Step 4: Proof reading -DNA polymerase checks for and corrects mismatched nucleotides and _________ (mutations)

The result? of DNA Replication -Two new DNA molecules are made. Why does your DNA replicate in a semi-conservative fashion?