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Hydrogen Peroxide: A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.


JoVE 10694

Mitochondria and peroxisomes are organelles that are the primary sites of oxygen usage in eukaryotic cells. Mitochondria carry out cellular respiration—the process that converts energy from food into ATP—the primary form of energy used by cells. Peroxisomes carry out a variety of functions, primarily breaking down different substances such as fatty acids.

Peroxisomes contain up to 50 enzymes and are surrounded by a single membrane. They carry out oxidative reactions that break down molecules and produce hydrogen peroxide (H2O2) as a by-product. H2O2 is toxic to cells, but the peroxisome contains an enzyme—catalase—that converts H2O2 into harmless water and oxygen. In addition, catalase uses H2O2 to break down alcohol in the liver into aldehyde and water. However, since H2O2 is produced in very low quantities in the body, other enzymes primarily degrade alcohol. A critical function of the peroxisome is to break down fatty acids in a process called β oxidation. The resulting product—acetyl-CoA—is released into the cytosol and can travel to the mitochondria, where it is used to produce ATP. In mammalian cells, the mitochondria also carry out β oxidation, as well as using products from the catabolism o

 Core: Cell Structure and Function

Eukaryotic Compartmentalization

JoVE 10689

One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles—such as the nucleus and mitochondria—that carry out particular functions. Since biological membranes are only permeable to a small number of substances, the membrane around an organelle creates a compartment with controlled conditions inside. These microenvironments are often distinct from the environment of the surrounding cytosol and are tailored to the specific functions of the organelle. For example, lysosomes—organelles in animal cells that digest molecules and cellular debris—maintain an environment that is more acidic than the surrounding cytosol, because its enzymes require a lower pH to catalyze reactions. Similarly, pH is regulated within mitochondria, which helps them carry out their function of producing energy. Additionally, some proteins require an oxidative environment for proper folding and processing, but the cytosol is generally reductive. Therefore, these proteins are produced by ribosomes in the endoplasmic reticulum (ER), which maintains the necessary environment. Proteins are often then transported within the cell through membrane-bound vesicles. The genetic material of eukaryotic cells is compartmentalized within the nucleus, which is surrounded by a double membrane called the nuclear envelope. Sma

 Core: Cell Structure and Function

Determining Rate Laws and the Order of Reaction

JoVE 10193

Source: Laboratory of Dr. Neal Abrams — SUNY College of Environmental Science and Forestry

All chemical reactions have a specific rate defining the progress of reactants going to products. This rate can be influenced by temperature, concentration, and the physical properties of the reactants. The rate also includes the intermediates…

 General Chemistry

Decontamination for Laboratory Biosafety

JoVE 10399

Robert M. Rioux and Zhifeng Chen, Pennsylvania State University, University Park, PA

Decontamination is essential for laboratory biosafety, as the accumulation of microbial contamination in the laboratory can lead to the transmission of disease. The degree of decontamination can be classified as either disinfection or sterilization.…

 Lab Safety

Determining the Empirical Formula

JoVE 10181

Source: Laboratory of Dr. Neal Abrams - SUNY College of Environmental Science and Forestry

Determining the chemical formula of a compound is at the heart of what chemists do in the laboratory every day. Many tools are available to aid in this determination, but one of the simplest (and most accurate) is the determination of the empirical…

 General Chemistry

Detecting Reactive Oxygen Species

JoVE 5654

Reactive oxygen species are chemically active, oxygen-derived molecules capable of oxidizing other molecules. Because of their reactive nature, there are many deleterious effects associated with unchecked ROS production, including structural damage to DNA and other biological molecules. However, ROS can also be mediators of physiological signaling. There is accumulating…

 Cell Biology

Isolation of Fecal Bacteria from Water Samples by Filtration

JoVE 10213

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - Arizona University
Demonstrating Author: Luisa Ikner

The quality of water destined for use in agricultural, recreational, and domestic settings is of great importance due to the potential for outbreaks of waterborne disease. Microbial agents implicated in such events…

 Environmental Microbiology

Overview of Biosensing

JoVE 5794

Biosensors are devices that use a wide range of biological processes and physical properties in order to detect either a biological molecule, such as a protein or cell, or a non-biological molecule, such as a chemical component or contaminant. This interdisciplinary field utilizes electrical, optical, electrochemical, or even mechanical properties to detect the presence…


Lead Analysis of Soil Using Atomic Absorption Spectroscopy

JoVE 10021

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University

Lead occurs naturally in soil, in levels ranging from 10-50 ppm. However, with the widespread use of lead in paint and gasoline in addition to contamination by industry, urban soils often have concentrations of lead significantly greater than background levels…

 Environmental Science

Enzyme Activity - Prep Student

JoVE 10584

Investigating the Effect of pH and Temperature on Peroxidase Activity
To make the extraction buffer for the peroxidase enzyme, mix equal volumes of 0.1 M sodium phosphate monobasic and 0.1 molar sodium phosphate dibasic solutions to achieve a final volume of 500 mL.
Test the resulting solution using a pH meter. The mixture should be between a pH…

 Lab Bio

Ozonolysis of Alkenes

JoVE 10339

Source: Vy M. Dong and Zhiwei Chen, Department of Chemistry, University of California, Irvine, CA

This experiment will demonstrate an example of an ozonolysis reaction to synthesize vanillin from isoeugenol (Figure 1). Ozonolysis of alkenes, an oxidation reaction between ozone and an alkene, is a common method to prepare…

 Organic Chemistry II

Sample Preparation for Analytical Characterization

JoVE 10205

Source: Laboratory of Dr. B. Jill Venton - University of Virginia

Sample preparation is the way in which a sample is treated to prepare for analysis. Careful sample preparation is critical in analytical chemistry to accurately generate either a standard or unknown sample for a chemical measurement. Errors in analytical chemistry…

 Analytical Chemistry

Microfabrication via Photolithography

JoVE 5789

The fabrication of BioMEMs devices is often done using a microfabrication technique called photolithography. This widely used method utilizes light to transfer a pattern onto a silicon wafer, and provides the basis for the fabrication of many types of BioMEMs devices.

This video presents the photolithography technique, shows how the…


Isolating Nucleic Acids from Yeast

JoVE 5096

One of the many advantages to using yeast as a model system is that large quantities of biomacromolecules, including nucleic acids (DNA and RNA), can be purified from the cultured cells.

This video will address the steps required to carry out nucleic acid extraction. We will begin by briefly outlining the growth and harvest, and lysis of yeast cells, which are the initial steps…

 Biology I

Imaging Approaches to Assessments of Toxicological Oxidative Stress Using Genetically-encoded Fluorogenic Sensors

1Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, 2Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, 3Oak Ridge Institute for Science and Education

JoVE 56945

 Cancer Research

RNA-based Reprogramming of Human Primary Fibroblasts into Induced Pluripotent Stem Cells

1Department of Dermatology, University of Colorado School of Medicine, Anschutz Medical Campus, 2Charles C. Gates Center for Regenerative Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, 3Stem Cell Biobank and Disease Modeling Core, University of Colorado School of Medicine, Anschutz Medical Campus

JoVE 58687

 Developmental Biology

Imaging Metals in Brain Tissue by Laser Ablation - Inductively Coupled Plasma - Mass Spectrometry (LA-ICP-MS)

1Elemental Bio-imaging Facility, University of Technology Sydney, 2Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 3Department of Pathology, The University of Melbourne, 4School of Earth Sciences, The University of Melbourne, 5Research School, Ruhr University, 6Department of Physiology, Monash University, 7ESI Ltd., Bozeman, 8Agilent Technologies, Mulgrave

JoVE 55042


Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators

1Department of Electrical and Computer Engineering, University of California, Davis, 2Digital Light Projection (DLP) Technology Development, Texas Instruments, 3Birck Nanotechnology Center and the Department of Electrical and Computer Engineering, Purdue University

JoVE 51251

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