#Signal transduction pathway examples free#

The second kind of protein with which PKC can interact is a protein that acts as an inhibitor. See Figure 9.10 for the phosphorylation pathway that activates ERK. When eIF-4E becomes phosphorylated, the mRNA unfolds, allowing protein synthesis in the nucleus to begin. ERK phosphorylates MNK1, which in turn phosphorylates eIF-4E, an elongation initiation factor that, with other initiation factors, is associated with mRNA.

A small sampling of responses is described below.įigure 9.14 ERK is a MAP kinase that activates translation when it is phosphorylated.

The results of signaling pathways are extremely varied and depend on the type of cell involved as well as the external and internal conditions. Using signal transduction pathways, receptors in the plasma membrane produce a variety of effects on the cell. Inside the cell, ligands bind to their internal receptors, allowing them to directly affect the cell’s DNA and protein-producing machinery. These questions address the following standards: The Science Practices Assessment Ancillary contains additional test questions for this section that will help you prepare for the AP exam. Many biological processes involved in growth, reproduction, and dynamic homeostasis include temporal regulation and coordination.Ģ.E.1 Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms.ħ.1 The student can connect phenomena and models across spatial and temporal scales.Ģ.34 The student is able to describe the role of programmed cell death in development and differentiation, the reuse of molecules, and the maintenance of dynamic homeostasis.

#Signal transduction pathway examples free#

Living systems store, retrieve, transmit, and respond to information essential to life processes.Ĭells communicate by generating, transmitting, and receiving chemical signals.ģ.D.4 Changes in signal transduction pathways can alter a cellular response.ġ.5 The student can re-express key elements of natural phenomena across multiple representations in the domain.ģ.36 The student is able to describe a model that expresses the key elements of signal transduction pathways by which a signal is converted into a cellular response.Ħ.1 The student can justify claims with evidence.ģ.37 The student is able to justify claims based on scientific evidence that changes in signal transduction pathways can alter a cellular response.Ħ.2 The student can construct explanations of phenomena based on evidence produced through scientific practices.ģ.39 The student is able to construct an explanation of how certain drugs affect signal reception and, consequently, signal transduction pathways.īiological systems utilize free energy and molecular building blocks to grow, to reproduce, and to maintain dynamic homeostasis. A learning objective merges required content with one or more of the seven science practices. The Learning Objectives listed in the Curriculum Framework provide a transparent foundation for the AP ® Biology course, an inquiry-based laboratory experience, instructional activities, and AP ® exam questions. Information presented and the examples highlighted in the section support concepts and learning objectives outlined in Big Idea 3 and Big Idea 2 of the AP ® Biology Curriculum Framework.

Conditions where signaling pathways are blocked or defective can be deleterious, preventative, or prophylactic examples include diabetes, heart disease, autoimmune disease, toxins, anesthetics, and birth control pills. Degradation of signaling molecules and dephosphorylation of intermediates of the pathway are two ways signals are terminated within cells. Termination of the cell signaling cascade is important to ensure that the response to a signal is appropriate in timing and intensity. Programmed cell death, or apoptosis, removes damaged or unnecessary cells and plays a vital role in development, including morphogenesis of fingers and toes. Cell division and growth are almost always stimulated by external signals called growth factors left unregulated, cell growth leads to cancer. As we will explore in more detail in later chapters, some pathways activate enzymes that interact within DNA transcription factors to promote gene expression, others can cause cells to store energy as glycogen as fat, or result in free energy availability in the form of glucose. This response can take many different forms, including protein synthesis, a change in cell metabolism, cell division and growth, or even cell death. The initiation of a signaling pathway results in a cellular response to changes in the external environment.