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

Explain why and how passive transport occurs
Understand the processes of osmosis and diffusion
Define tonicity and describe its relevance to passive transport

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

Discuss the role of carbohydrates in cells and in the extracellular materials of animals and plants
Explain the classifications of carbohydrates
List common monosaccharides, disaccharides, and polysaccharides

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

Describe the four major types of lipids
Explain the role of fats in storing energy
Differentiate between saturated and unsaturated fatty acids
Describe phospholipids and their role in cells
Define the basic structure of a steroid and some functions of steroids
Explain the how cholesterol helps to maintain the fluid nature of the plasma membrane

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

Describe the structure of nucleic acids and define the two types of nucleic acids
Explain the structure and role of DNA
Explain the structure and roles of RNA

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

Describe the functions proteins perform in the cell and in tissues
Discuss the relationship between amino acids and proteins
Explain the four levels of protein organization
Describe the ways in which protein shape and function are linked

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

Understand the synthesis of macromolecules
Explain dehydration (or condensation) and hydrolysis reactions

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

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:

Explain why carbon is important for life
Describe the role of functional groups in biological molecules

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

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

By the end of this section, you will be able to:Identify the shared characteristics of the natural sciencesSummarize the steps of the scientific methodCompare inductive reasoning with deductive reasoningDescribe the goals of basic science and applied science

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

Identify and describe the properties of life
Describe the levels of organization among living things
Recognize and interpret a phylogenetic tree
List examples of different sub disciplines in biology

In this video collaboration from Khan Academy and 23andMe, you'll learn about the basics of cells, chromosomes, and the genes contained in your DNA.

In this video collaboration from Khan Academy and 23andMe, you'll learn about the basics of cells, chromosomes, and the genes contained in your DNA.

In this video collaboration from Khan Academy and 23andMe, you'll learn about the variations in human DNA called SNPs, and how they can be used to understand relationships between people.

In this video collaboration from Khan Academy and 23andMe, you'll learn about the variations in human DNA called SNPs, and how they can be used to understand relationships between people.