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Protein folding and trafficking is essential for normal cell function, and when it goes awry it can lead to various chronic conditions, including fatty liver disease, diabetes, and Parkinson's. The narrative of this case study follows two undergraduate students engaged in a summer research project evaluating the effects of cell stress on cell function and health in the model organism Caenorhabditis elegans (C. elegans).  During the case study, students review animal cell organelle function and then learn about endoplasmic stress and unfolded protein response. Prior knowledge needed for the case is basic animal cell organelles and their functions and use of model organisms in research. The case was designed for a flipped classroom in which students prepare in advance by taking a quiz and watching two videos; a PowerPoint animation is also included.

The collection of proteins within a cell determines its health and function. Proteins are responsible for nearly every task of cellular life, including cell shape and inner organization, product manufacture and waste cleanup, and routine maintenance. Proteins also receive signals from outside the cell and mobilize intracellular response. They are the workhorse macromolecules of the cell and are as diverse as the functions they serve.

Signaling at the neuromuscular junction (NMJ) is a complex process that is required for many actions that sustain life within humans. Toxins that act upon the NMJ, both natural and synthetic, act in a variety of ways to inhibit this function. This case study examines how a variety of toxins can act to disrupt the normal mechanism of function of the NMJ  by placing a protagonist ("Unlucky Chucky") at an eco-spa in Colombia with his good friend Melody. Unfortunately, during their time at the eco-spa, things don't always turn out well for Chucky. A variety of neuromuscular toxins are discussed including curare (d-tubocurarine), Botox (botulinum toxin A), physostigmine and sarin gas (GB). This case was designed to be used in a variety of classrooms ranging from an undergraduate introduction to biology course in a module focused on neuromuscular functioning, to an introduction to physiology course as an introduction to the NMJ; it could also potentially be used in a nursing course that is examining NMJ physiology.

This interrupted case study explores the role of cytoskeletal structures on human health, specifically on respiratory function, sperm motility, and female fertility. It follows the story of a couple struggling to conceive a child and the doctors working to help them. Students are presented with clinical histories, narrative elements, documentary-style videos, and microscopic evidence in order to determine the cause of the couple's infertility. Along the way, they learn about the three types of cytoskeletal elements and the roles these play in cellular biology and human physiology. The use of videos makes it suitable for the "flipped classroom," allowing students to prepare outside the classroom for the case study, which they then complete in class. An original video by the author on the structure and function of microtubules, microfilaments, and intermediate filaments is included. The case was developed for an introductory level general biology course and could be delivered during a unit on the cell structure and function. The case could also be used in a cell biology course.

UCLA researchers now have the first evidence that bacteria ingested in food can affect brain function in humans. In an early proof-of-concept study of healthy women, they found that women who regularly consumed beneficial bacteria known as probiotics through yogurt showed altered brain function, both while in a resting state and in response to an emotion-recognition task.

In the August 1 issue of CELL, researchers from the Gene and Stem Cell Therapy Program at Sydney's Centenary Institute revealed another function of introns, or noncoding nucleotide sequences, in DNA. They reported that gene-sequencing techniques and computer analysis allowed them to demonstrate how granulocytes use noncoding DNA to regulate the activity of a group of genes that determines the cells' shape and function.

Inside the cell: -cell function, -interactive, functions, specialization, mitosis, aging/death, glossary

One of the most important molecules relating to cancer is called p53. This Click and Learn explains the structure and function of the p53 protein as well as how the protein's activity is regulated. Learn why p53 is called the guardian of the genome and how interfering with its function can lead to cancer.

In order to improve the surgical outcome of these procedures and enhance patient quality of life, new and better tools are needed for esophageal reconstruction. Biostage is working on a new regenerative technology to address esophageal cancer through their pioneer Cellframe Technology. Two weeks before the surgery, stem cells are harvested from patient abdominal adipose tissue and allowed to incubate with a biocompatible esophageal implant. These cells interact and adhere to the implant and are able to respond to signals for regeneration once inside the patient, potentially restoring both the structural and functional integrity of the esophagus. These new approaches to organ implants could revolutionize resectional surgery by providing patients with functional replacements derived from their own cells.

This interrupted case study tells the story of Michael, a Harvard law graduate with a stressful job and a seemingly heavy drinking problem. Students are provided with background information, medical history, and lab results in order to guide them towards determining what is wrong with Michael. This study highlights cirrhosis and the effects of alcohol abuse on the liver. Before beginning the case study, students should have a background in the physiological role of the liver and the breakdown of hemoglobin. Students are asked to use the information provided for them in the case study to gather more information about liver cells and their functions, alcohol, and alcoholic liver damage. Ultimately, using multiple blood tests, the Maddrey's discriminant function (DF) score, and results from a magnetic resonance elastography (MRE), they will diagnose Michael with alcoholic cirrhosis. This case was developed for use in a non-majors physiology course, but could easily be used for a majors class.

An elderly woman living independently with some help from her family is brought to the local emergency room because she is confused and vomiting. While her son suspects a stroke, a quick battery of laboratory tests indicates that her current problems are the result of impaired kidney function, an old-fashioned home remedy for ulcers, and her prescribed blood pressure medication. The combination of patient- and drug-related factors produces an acid-base disorder responsible for her confusion. This disorder further disrupts her kidney function. The case illustrates secretion and reabsorption processes in the kidney tubule which regulate plasma and urinary electrolytes (including calcium) and pH. The role of bicarbonate in maintaining systemic pH is emphasized. Interactions among the renal, respiratory and nervous systems in the regulation of systemic pH are also illustrated. Further, basic principles of pharmacotherapy and issues related to the appropriate use of medications are introduced. The case was developed for use in a physiology or human anatomy and physiology course, but it might be used in undergraduate nursing courses as well (e.g., pharmacology, pathophysiology).

This case study introduces students to the structure and function of cellular organelles and seeks to show their importance by discussing diseases and disorders that can result when an organelle does not function as it should. The storyline follows a family whose joy at bringing home a new baby is soon altered by their child's sudden illness, which is eventually diagnosed as Leigh Disease. This disease occurs when defective mitochondria fail to produce energy needed by the cell, particularly affecting cells with high-energy needs like those in the brain, muscle, and gastrointestinal tract. The narrative also discusses some of the ways in which Leigh disease is inherited, treatment options, and the typical prognosis. The case was designed for an introductory non-majors biology course, but could also be used in other science or health related courses. Instructors also have the option of running the case in a "flipped classroom" in which students watch three recommended videos outside of class as a way of preparing for working on the case in class.

Current CRISPR-based screens often mutate the beginning of a gene, which sometimes results in the expression of a functional protein variant. To circumvent this problem, researchers at Cold Spring Harbor Laboratory (CSHL) designed CRISPR guide RNAs that would mutate the portion of a gene encoding a domain on the surface of the protein where a small molecule could bind to alter the protein's function. The team had previously identified such a binding pocket on the protein BRD4, and a small molecule inhibitor that binds in the pocket is an effective leukemia treatment.

The origin of viruses remains mysterious because of their diverse and patchy molecular and functional makeup. Although numerous hypotheses have attempted to explain viral origins, none is backed by substantive data. We take full advantage of the wealth of available protein structural and functional data to explore the evolution of the proteomic makeup of thousands of cells and viruses. Despite the extremely reduced nature of viral proteomes, we established an ancient origin of the "viral supergroup" and the existence of widespread episodes of horizontal transfer of genetic information. Viruses harboring different replicon types and infecting distantly related hosts shared many metabolic and informational protein structural domains of ancient origin that were also widespread in cellular proteomes. Phylogenomic analysis uncovered a universal tree of life and revealed that modern viruses reduced from multiple ancient cells that harbored segmented RNA genomes and coexisted with the ancestors of modern cells. The model for the origin and evolution of viruses and cells is backed by strong genomic and structural evidence and can be reconciled with existing models of viral evolution if one considers viruses to have originated from ancient cells and not from modern counterparts.

The dewlaps of Anolis lizards provide a classic example of a complex signaling system whose function and evolution is poorly understood. Dewlaps are flaps of skin beneath the chin that are extended and combined with head and body movements for visual signals and displays. They exhibit extensive morphological variation and are one of two cladistic features uniting anoles, yet little is known regarding their function and evolution.

The life science/biology course is divided into 12 instructional segments grouped into four sections. In the first section, From Molecules to Organisms: Structures and Processes, students develop models of how molecules combine to build cells and organisms (IS1 [Structure and Function]; IS2 [Growth and Development of Organisms]; IS3 [Organization for Matter and Energy Flow in Organisms]). In the second section, Ecosystems: Interactions, Energy, and Dynamics, students zoom out to the macroscopic scale to show how organisms interact (IS4 [Interdependent Relationships in Ecosystems]; IS5 [Cycles of Matter and Energy Transfer in Ecosystems]; IS6 [Ecosystem Dynamics, Functioning, and Resilience]; IS7 [Social Interactions and Group Behavior]). Students return to the role that DNA plays in inheritance during the third section, Heredity: Inheritance and Variation of Traits (IS8 [Inheritance of Traits]; IS9 [Variation of Traits]). The class ends tying together interactions at all these scales by explaining evolution and natural selection in Biological Evolution: Unity and Diversity (IS10 [Evidence of Common Ancestry and Diversity]; IS11 [Natural Selection]; IS12 [Adaptation and Biodiversity]). A vignette in IS12 illustrates the level of three-dimensional understanding students are expected to exhibit as a capstone of the course.

This directed case study examines the molecular basis of cystic fibrosis to emphasize the relationship between the genetic code stored in a DNA sequence and the encoded protein's structure and function. Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein that functions to help maintain salt and water balance along the surface of the lung and gastrointestinal tract. This case introduces students to "Maggie," who has just been diagnosed with cystic fibrosis. The students must identify the mutation causing Maggie's disease by transcribing and translating a portion of the wildtype and mutated CFTR gene. Students then compare the three-dimensional structures of the resulting proteins to better understand the effect a single amino acid mutation can have on the overall shape of a protein. Students also review the concepts of tonicity and osmosis to examine how the defective CFTR protein leads to an increase in the viscosity of mucus in cystic fibrosis patients. This case was developed for use in an introductory college-level biology course but could also be adapted for use in an upper-level cell or molecular biology course.

Explore some examples of specialized plant and animal cells with the Amoeba Sisters! This video explains how specialized cell structure suits their function.

Stress isn't always a bad thing; it can be handy for a burst of extra energy and focus, like when you're playing a competitive sport or have to speak in public. But when it's continuous, it actually begins to change your brain. Madhumita Murgia shows how chronic stress can affect brain size, its structure, and how it functions, right down to the level of your genes.

Article describing possible function of introns.