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Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)

Light as Energy

JoVE 10749

The energy required to carry out photosynthesis is light—typically radiation from the sun. The electromagnetic particles are called photons and carry a defined amount of energy, dependent on the wavelength. All wavelengths fall within a range called the electromagnetic spectrum. Plants carry out photosynthesis using wavelengths that range from 400 to 700 nm. They primarily use a pigment called chlorophyll a that absorbs red and blue light and reflects green light which is why leaves appear green. A photon is a discrete electromagnetic particle or bundle of energy. It is always in motion and travels at the speed of light. Photons are characterized by their frequency, wavelength, and amplitude, similar to the properties of a wave. Waves with higher frequencies transmit more energy and have shorter wavelengths than longer wavelengths that transmit less energy and have lower frequencies. The range of all possible wavelengths is known as the electromagnetic spectrum. For most organisms, photosynthesis relies on a small segment of the electromagnetic spectrum—namely, the visible portion that ranges from 400 to 700 nanometers, from blue to green to red. However, a few organisms can carry out photosynthesis using infrared light. In plants, different pigment molecules absorb specific wavelengths of light, giving each molecule a disti

 Core: Photosynthesis

Diffusion

JoVE 10700

Diffusion is the passive movement of substances down their concentration gradients—requiring no expenditure of cellular energy. Substances, such as molecules or ions, diffuse from an area of high concentration to an area of low concentration in the cytosol or across membranes. Eventually, the concentration will even out, with the substance moving randomly but causing no net change in concentration. Such a state is called dynamic equilibrium, which is essential for maintaining overall homeostasis in living organisms. Diffusion plays an integral role in biological processes such as respiration, the process by which organisms exchange gases with their environment. After breathing in air, the concentration of oxygen in the alveoli, air sacs of the human lung, is higher than the oxygen concentration in the blood. Consequently, oxygen diffuses down its concentration gradient into the blood. In order to get into body tissue, oxygen and other nutrients carried in the blood must diffuse into tissues down their concentration gradients. Metabolic waste such as carbon dioxide diffuses from tissues into capillaries where the carbon dioxide concentration is less than that inside body tissues. Blood carrying carbon dioxide is then pumped to the lungs where carbon dioxide readily diffuses into alveoli that have a lower concentration of the gas than blood. Carbon dioxide

 Core: Membranes and Cellular Transport

Sonication Extraction of Lipid Biomarkers from Sediment

JoVE 10055

Source: Laboratory of Jeff Salacup - University of Massachusetts Amherst


The material comprising the living "organic" share of any ecosystem (leaves, fungi, bark, tissue; Figure 1) differs fundamentally from the material of the non-living "inorganic" share (rocks and their constituent minerals, oxygen, …

 Earth Science

Using High Resolution Computed Tomography to Visualize the Three Dimensional Structure and Function of Plant Vasculature

1U.S. Department of Agriculture, 2Department of Viticulture and Enology, University of California - Davis, 3Hawkesbury Institute for the Environment, University of Western Sydney, 4Advanced Light Source, Lawrence Berkeley National Lab, 5Citrus Research & Education Center, University of Florida

JoVE 50162

 Biology

A Rapid Laser Probing Method Facilitates the Non-invasive and Contact-free Determination of Leaf Thermal Properties

1Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V., 2Institute for Molecular Biotechnology, RWTH Aachen University, 3Fraunhofer Institute for Laser Technology ILT, Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V.

JoVE 54835

 Biochemistry

Assessing the Particulate Matter Removal Abilities of Tree Leaves

1Key Laboratory of Silviculture and Conservation of Ministry of Education, Beijing Forestry University, 2School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University

JoVE 58026

 Environment

Stomata Tape-Peel: An Improved Method for Guard Cell Sample Preparation

1Plant Molecular and Cellular Biology Program, University of Florida, 2Department of Biology, University of Florida, 3Genetics Institute (UFGI), University of Florida, 4Alkali Soil Natural Environmental Science Center, Northeast Forestry University, 5Interdisciplinary Center for Biotechnology Research (ICBR), University of Florida

JoVE 57422

 Biology

A Flexible Low Cost Hydroponic System for Assessing Plant Responses to Small Molecules in Sterile Conditions

1Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center for Research in energy and materials (CNPEM), 2University of Campinas (UNICAMP), 3University of Viçosa (UFV), 4CTBE, CNPEM, 5Brazilian Bioethanol Science and Technology Laboratory (CTBE/CNPEM), Max Planck Partner Group

JoVE 57800

 Environment

The Plant Infection Test: Spray and Wound-Mediated Inoculation with the Plant Pathogen Magnaporthe Grisea

1Beijing Key Laboratory of New Technology in Agricultural Application, National Demonstration Center for Experimental Plant Production Education, Beijing University of Agriculture, 2College of Plant Protection, State Key Laboratory of Agrobiotechnology, Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University

JoVE 57675

 Environment

Luminescence Lifetime Imaging of O2 with a Frequency-Domain-Based Camera System

1Marine Biological Section, Department of Biology, University of Copenhagen, 2Center for Electromicrobiology, Aarhus University, 3PCO AG, 4Climate Change Cluster, University of Technology Sydney, 5Aarhus University Centre for Water Technology, Section for Microbiology, Department of Bioscience, Aarhus University

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JoVE 60191

 JoVE In-Press
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