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Chloroplast Structure & Light Dependent Reactions (Photosystem 1 and 2 Cyclic Electron Flow)

By: HWC, Views: 6282

The leaf is the principle photosynthetic organ of the plant. This is a cross section of a leaf. The rectangular-shaped cells are part of the photosynthetic tissue called the palisade mesophyll. Each photosynthetic cell can contain several hundred organelles known as chloroplasts. The chlorop...

The Pressure Flow Model in a Plant

By: HWC, Views: 6014

The vascular system of plants has two transport tissues, called xylem and phloem. Xylem transports water and minerals, while phloem transports a variety of dissolved substances, including sugars and amino acids, throughout the plant. Water in the xylem always moves up, in the direction from th...

Origin of organelles Animation

By: HWC, Views: 286

Possible origins of the nucleus and other organelles. Some prokaryotic cells have infoldings of their plasma membrane. These infoldings may have served as channels from the cytoplasm to the cell surface. These membranous folds may have evolved into the endoplasmic reticulum and the nuclear e...

How eudicots (true dicots) differ from monocots Animation

By: HWC, Views: 1519

Most flowering plants are either monocots or eudicots. They have the same tissues, but slightly different features. Monocot seeds have a single cotyledon, or seed leaf. Eudicot seeds have two cotyledons. Monocot flowers usually have petals and other floral parts in multiples of three. Flow...

Calvin cycle (The light-independent reactions )

By: HWC, Views: 6411

The light-independent reactions of photosynthesis occur in the stroma of the chloroplast. Carbon dioxide enters the leaf through tiny pores or stomata and diffuses into the chloroplast. The first stage of the Calvin cycle is the attachment of a carbon dioxide molecule to a 5-carbon ribulose bi...

Photosynthesis and Van Helmont Experiment

By: HWC, Views: 5918

All energy on Earth comes from a star, the Sun. Light must travel 160 million kilometers to reach Earth where plants capture this light energy and convert it to chemical energy in the form of sugars. This biochemical process is called PHOTOSYNTHESIS. The summary equation for photosynthesis is ...

Erythropoietin (EPO)

By: HWC, Views: 6205

■ Secreted by kidney cells when blood oxygen is low. ■ Targets cells in red bone marrow that will become red blood cells. ■ Promotes increased numbers of mature red blood cells. ■ More mature red blood cells carry more oxygen so blood oxygen level is restored to normal.

T cell receptors

By: HWC, Views: 6344

• T cells are responsible for cell-mediated immunity. • Each T cell contains a unique form of T cell receptor (TCR) on its membrane. • These T cell receptors are produced through a process of genetic recombination which is able to produce millions of different variations. • Each T ce...

Cytotoxic T cell receptors, activation, proliferation, differentiation & action

By: HWC, Views: 6994

• Most cells which have CD8 on their surface become cytotoxic T cells (Tc cells). • CD8 T cells recognize a foreign antigen when it is presented in conjunction with the protein, MHC-I. • Nearly all nucleated cells in the body express MHC-I molecules. • T cells that recognize self-pe...