This interactive will present the mathematical consideration of exponentially
enriching a piece of DNA using PCR. Typically, a PCR protocol will repeat
approximately 30 cycles of denaturation, annealing, and elongation. 30 cycles of
PCR produce around 1 billion copies of the amplified region.

A video discussing a variety of biotechnology applications that can be completed based on DNA's chemical properties. [2:44]

Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.

By the end of this section, you will be able to do the following:

Define matter and elements
Describe the interrelationship between protons, neutrons, and electrons
Compare the ways in which electrons can be donated or shared between atoms
Explain the ways in which naturally occurring elements combine to create molecules, cells, tissues, organ systems, and organisms

By the end of this section, you will be able to do the following:

Describe the properties of water that are critical to maintaining life
Explain why water is an excellent solvent
Provide examples of water’s cohesive and adhesive properties
Discuss the role of acids, bases, and buffers in homeostasis

Covers the structure and properties of water.

A free CK-12 account is required to view all materials.

Covers the structure and properties of water.

A free CK-12 account is required to view all materials.

This interactive image allows the user to control the environmental temperature
and observe its impact on the strength of the hydrogen bonds between
complementary strands in a DNA molecule.

A site showing the structures of water and ice and explaining how they are affected by hydrogen bonds. Includes a movie animating hydrogen bond formation and disruption.

This interactive will present the components and steps needed for a successful
PCR reaction.

This interactive will present the rules for designing precise nucleotide sequences
called PCR primers. Designing primers for a PCR reaction is an important step
because the way they bind to the template DNA dictates much of the success of
the PCR reaction.

Polymerase Chain Reaction - or PCR - is known as one of the most ubiquitous and powerful techniques in life science laboratories. PCR is a highly sensitive and selective method to produce many copies of a particular piece of DNA. This pathway details applications of PCR, its mechanism and primer design, and demonstrates how the method is used in the lab.

This pathway explores the properties of water that make it essential for life. Key properties of water discussed in this pathway include water as a solvent, hydrogen bonding, specific heat and cohesion.

In this scrollable interactive, the four levels of protein folding are explored in detail by exploring the structure of hemoglobin.

This pathway provides an introduction to the structure of water and properties of water, such as hydrogen bonding, that make it essential for life. For a deeper look at this topic, we recommend the pathway The Chemical Foundation of Life from the OpenStax textbook Biology for AP® Courses.