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:

Describe how signaling pathways direct protein expression, cellular metabolism, and cell growth
Identify the function of PKC in signal transduction pathways
Recognize the role of apoptosis in the development and maintenance of a healthy organism

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

Describe the extracellular matrix
List examples of the ways that plant cells and animal cells communicate with adjacent cells
Summarize the roles of tight junctions, desmosomes, gap junctions, and plasmodesmata

"This course covers the principles of materials science and cell biology underlying the design of medical implants, artificial organs, and matrices for tissue engineering. Methods for biomaterials surface characterization and analysis of protein adsorption on biomaterials. Molecular and cellular interactions with biomaterials are analyzed in terms of unit cell processes, such as matrix synthesis, degradation, and contraction. Mechanisms underlying wound healing and tissue remodeling following implantation in various organs. Tissue and organ regeneration. Design of implants and prostheses based on control of biomaterials-tissue interactions. Comparative analysis of intact, biodegradable, and bioreplaceable implants by reference to case studies. Criteria for restoration of physiological function for tissues and organs."

Biology of cells of higher organisms: structure, function, and biosynthesis of cellular membranes and organelles; cell growth and oncogenic transformation; transport, receptors and cell signaling; the cytoskeleton, the extracellular matrix, and cell movements; chromatin structure and RNA synthesis.

Basic molecular structural principles of biological materials. Molecular structures of various materials of biological origin, including collagen, silk, bone, protein adhesives, GFP, self-assembling peptides. Molecular design of new biological materials for nanotechnology, biocomputing and regenerative medicine. Graduate students are expected to complete additional coursework. This course, intended for both graduate and upper level undergraduate students, will focus on understanding of the basic molecular structural principles of biological materials. It will address the molecular structures of various materials of biological origin, such as several types of collagen, silk, spider silk, wool, hair, bones, shells, protein adhesives, GFP, and self-assembling peptides. It will also address molecular design of new biological materials applying the molecular structural principles. The long-term goal of this course is to teach molecular design of new biological materials for a broad range of applications. A brief history of biological materials and its future perspective as well as its impact to the society will also be discussed. Several experts will be invited to give guest lectures.

The principles and practice of tissue engineering (and regenerative medicine) are taught by faculty of the Harvard-MIT Division of Health Sciences and Technology (HST) and Tsinghua University, Beijing, China. The principles underlying strategies for employing selected cells, biomaterial scaffolds, soluble regulators or their genes, and mechanical loading and culture conditions, for the regeneration of tissues and organs in vitro and in vivo are addressed. Differentiated cell types and stem cells are compared and contrasted for this application, as are natural and synthetic scaffolds. Methodology for the preparation of cells and scaffolds in practice is described. The rationale for employing selected growth factors is covered and the techniques for incorporating their genes into the scaffolds are examined. Discussion also addresses the influence of environmental factors including mechanical loading and culture conditions (e.g., static versus dynamic). Methods for fabricating tissue-engineered products and devices for implantation are taught. Examples of tissue engineering-based procedures currently employed clinically are analyzed as case studies.