Active transport is reliant on carrier proteins and thus follows the same rules as facilitated diffusion in that they are specific have a maximum rate and are subject to competition. Crucially they transport substances against their concentration gradient and so require energy to work.

Biochemistry is the study of the chemical processes and compounds, such as cellular makeup, that bring about life in organisms. This course will look at how these formed biomolecules interact and produce many of life's necessary processes. Also it will look at the most commonly used techniques in biochemistry research. Upon successful completion of this course, students will be able to: recognize and describe the structure of the following basic biomolecules: nucleic acids, amino acids, lipids, carbohydrates; diagram how these basic biomolecules are used as building blocks for more complex biomolecules; differentiate between reactions that create biomolecules; describe how these biomolecules are used in specific cellular pathways and processes; analyze how feedback from one pathway influences other pathways; explain how energy is utilized by a cell; indicate how biomolecules and pathways are regulated; describe how enzymes play a key role in catalysis; assess which biochemical technique should be used to study a given biochemical problem. (Biology 401; See also: Chemistry 109)

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:

List the steps in eukaryotic transcription
Discuss the role of RNA polymerases in transcription
Compare and contrast the three RNA polymerases
Explain the significance of transcription factors

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

List the different steps in prokaryotic transcription
Discuss the role of promoters in prokaryotic transcription
Describe how and when transcription is terminated

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

Describe the different steps in RNA processing
Understand the significance of exons, introns, and splicing for mRNAs
Explain how tRNAs and rRNAs are processed

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

Describe the different steps in protein synthesis
Discuss the role of ribosomes in protein synthesis

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

Explain the “central dogma” of DNA-protein synthesis
Describe the genetic code and how the nucleotide sequence prescribes the amino acid and the protein sequence

Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

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

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

The endoplasmic reticulum (ER) orchestrates different cellular processes by which proteins are synthesized, correctly folded, modified and ultimately transported to their final destinations. As part of this crucial biosynthetic process, proteins that are not properly folded and consequently detrimental to normal cellular function are constantly generated. A common signature of many neurodegenerative diseases, including Alzheimer's and Parkinson's, is accumulation and deposition of misfolded proteins that arise when the ability of cells to deal with the burden of misfolded proteins is compromised. In this course, we will explore how the ER quality control machinery ensures that only properly assembled proteins exit the ER while distinguishing between nascent proteins en route to their biologically active folded state from those that are terminally misfolded.

View the animation to see how one type of immune cell-the helper T cell-interprets a message presented at the surface of the cell membrane. The message is an antigen, a protein fragment taken from an invading microbe. A series of events unfolds that results in the production of many clones of the helper T cell. These identical T cells can serve as a brigade forming an essential communication network to activate B cells, which make antibodies that will specifically attack the activating antigen.

This is a course developed for students who are going to do evolution for the first time. Therefore, they should have working knowledge of the chromosome theory and the nature of meiosis with particular reference to recombination and its advantages in the process of reproduction. They should also be conversant with the principles and concepts of Mendelian and post Mendelian genetics to be able to describe such terms as genotype, phenotype and variation. This will require them to know that a gene is the unit of heredity and that it is located on the Deoxyribonucleic acid (DNA) molecule. They should understand the structure and role of DNA, as the universal molecule that specifies the amino acid sequence of proteins in cells of organisms. This knowledge should be of an elementary type as described in Advanced Level Biology textbooks.

The MIT Biology Department core courses, 7.012, 7.013, and 7.014, all cover the same core material, which includes the fundamental principles of biochemistry, genetics, molecular biology, and cell biology. Biological function at the molecular level is particularly emphasized and covers the structure and regulation of genes, as well as, the structure and synthesis of proteins, how these molecules are integrated into cells, and how these cells are integrated into multicellular systems and organisms. In addition, each version of the subject has its own distinctive material.

Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.