Module 1 is aligned with the following course objectives.

• Distinguish living organisms based on the characteristics of life
• Describe the chemical components of life
• Test predictions from scientific hypotheses using basic biological laboratory techniques
• Relate cell structure to function

Chapter 1 Summary

Biology is the science of life. All living organisms share several key properties such as order, sensitivity or response to stimuli, reproduction, growth and development, regulation, homeostasis, and energy processing. Living things are highly organized parts of a hierarchy that includes atoms, molecules, organelles, cells, tissues, organs, and organ systems. Organisms, in turn, form a hierarchy of populations, communities, ecosystems, and the biosphere. A diagram called a phylogenetic tree can be used to visualize relationships among organisms. The tree of life has three main branches: Bacteria, Archaea, and Eukarya.

Chapter 2 Summary

Elements in various combinations comprise all matter, including living things. Some of the most abundant elements in living organisms include carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur. These form the four major molecules of life: carbohydrates, lipids, proteins, and nucleic acids. Water has many properties that are critical to maintaining life. Atoms are the smallest units of an element that retain all of the properties of that element and consist of protons, neutrons, and electrons. Electrons can transfer, share, or cause charge disparities between atoms to create bonds, including ionic, covalent, and hydrogen bonds. These bonds form molecules.

Chapter 3 Summary

Carbohydrates, lipids, proteins, and nucleic acids are the four biological macromolecules—large molecules necessary for life. These four are built from smaller organic molecules. Macromolecules are made up of single units known as monomers,  joined by covalent bonds to form larger polymers. Carbohydrates provide a vital energy source for all cell types and provide structural support to plant cells. Lipids are nonpolar and hydrophobic in nature. Major lipid types include fats and oils, waxes, and phospholipids (famous for forming plasma membranes). Proteins perform a diverse range of functions for the cell. They help in metabolism, provide structural support and act as enzymes, carriers, or hormones. The building blocks of proteins (monomers) are amino acids.  Protein shape and function are linked, as any change in shape may lead to protein denaturation and subsequent loss in function. Nucleic acids hold the instructions for building proteins. There are four DNA nucleotides (ATCG) and four RNA nucleotides (AUCG).

Chapter 4 Summary

A cell is the smallest unit of life. Most cells cannot be seen with the naked eye, and microscopes allow us to visualize cells. Teaching labs use light microscopes, and some research labs use electron microscopes. All prokaryotes have plasma membranes, cytoplasm, ribosomes, and DNA that is not membrane-bound. Like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes, but a eukaryotic cell is typically larger than a prokaryotic cell, has a true nucleus (meaning its DNA is surrounded by a membrane), and has other membrane-bound organelles that allow for compartmentalization of functions. The plasma membrane is a phospholipid bilayer embedded with proteins. Ribosomes provide a location for protein synthesis. Mitochondria are responsible for the majority of ATP produced in the cell. Lysosomes digest macromolecules, recycle worn-out organelles, and destroy pathogens. The RER modifies proteins and synthesizes phospholipids. The SER engages in detoxification and more. Sorting, tagging, packaging, and distribution take place in the Golgi apparatus. The cytoskeleton has three different types of protein elements, microfilaments, intermediate filaments, and microtubules.