Unit 8: DNA Structure & Function
Reading
BJU Biology: Section 2.6 - "Proteins and nucleic acids"
OpenStax Biology - Ch. 14 "DNA Structure and Function"
Topic
Lab options (depending on time available)
BJU Biology: Section 2.6 - "Proteins and nucleic acids"
OpenStax Biology - Ch. 14 "DNA Structure and Function"
Topic
- DNA structure and function
- DNA replication
Lab options (depending on time available)
- Lac Operon "Gene Switches" lab
- HHMI Transgenic Fly lab
- Bio-Rad pGLO Bacterial Transformation lab
- PhET Gene Expression lab
- PhET Gene Machine Lac Operon lab
Diagram: Unwinding and copying the two strands of DNA
| 10._dna_replication_lecture_slides_2023.pptx |
Introduction
When a cell divides, it must first replicate all its DNA so that each daughter cell receives a complete copy. DNA replication occurs in all living organisms - humans, whales, finches, corn plants, and fruit flies.
When a cell divides, it must first replicate all its DNA so that each daughter cell receives a complete copy. DNA replication occurs in all living organisms - humans, whales, finches, corn plants, and fruit flies.
When a cell divides during mitosis, it is important that each daughter cell receives an identical copy of the DNA. If it didn't, it would be dead on arrival!
Copying of the DNA is accomplished by the process of DNA replication - also known as DNA synthesis. This occurs in the S phase of the cell cycle. After that particular cell - let's say a skin cell - completes its synthesis phase, it then moves on the G2 phase - hopefully passes through the G2 quality checkpoint - and ultimately moves on to the mitosis phase where it actually divides.
DNA replication is carried out by a molecular machine known as DNA polymerase, which is a complex assemblage of many protein subunits. The DNA polymerase package - known as the replisome - acts like a moving factory, simultaneously copying one strand of DNA forwards, and the other strand of DNA backwards, by an ingenious sliding-looping-ratcheting mechanism.
In eukaryotes (humans, pea plants, dolphins, and yeast) DNA replication occurs in the nucleus - after all, that's where the DNA resides.
In prokaryotes (think: bacteria) DNA replication occurs right out in the cytoplasm itself, because that's where bacterial DNA resides.
Copying of the DNA is accomplished by the process of DNA replication - also known as DNA synthesis. This occurs in the S phase of the cell cycle. After that particular cell - let's say a skin cell - completes its synthesis phase, it then moves on the G2 phase - hopefully passes through the G2 quality checkpoint - and ultimately moves on to the mitosis phase where it actually divides.
DNA replication is carried out by a molecular machine known as DNA polymerase, which is a complex assemblage of many protein subunits. The DNA polymerase package - known as the replisome - acts like a moving factory, simultaneously copying one strand of DNA forwards, and the other strand of DNA backwards, by an ingenious sliding-looping-ratcheting mechanism.
In eukaryotes (humans, pea plants, dolphins, and yeast) DNA replication occurs in the nucleus - after all, that's where the DNA resides.
In prokaryotes (think: bacteria) DNA replication occurs right out in the cytoplasm itself, because that's where bacterial DNA resides.
Homework
| 10._dna_replication_homework_questions_2023.docx |