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Oogenesis Animation

By: Administrator, Views: 9773

Located on either side of the uterus, ovaries are almond-shaped organs attached to the uterus by the ovarian ligament and lie close to the fimbriae of the fallopian tubes. The anterior border of each ovary is connected to the posterior layer of the broad ligament by the mesovarium (portion of th...

Major Elements in Biological Molecules: Proteins

By: HWC, Views: 6032

Proteins are chains of amino acids linked by peptide bonds. The 20 different amino acids used to make all proteins differ only in their side chains, and the properties of these side chains account for the great diversity of protein structure and function. Collagen is an example of how a prote...

Hierarchical Sequencing Method - Sequence Tagged Sites

By: HWC, Views: 5848

In the hierarchical sequencing method, researchers begin by collecting cells. In humans, each cell contains 23 pairs of chromo-somes. Here we specifically track the DNA from just one of the 23 pairs. Chromosomes have a series of unique DNA sequences, called sequence-tagged sites (STSs), that a...

Structures that affect circulation - arterioles and vasomotor responses and venous return

By: HWC, Views: 6715

■ Small arteries and arterioles determine SVR. • Blood pressure drops significantly as blood passes through arterioles. • Decreasing arteriole radius and decreased wall elasticity are the main reasons for increased SVR. ■ Small changes in arteriole radius can cause large changes in ...

Phases of an Action Potential - Resting Potential, Threshold, Rising, Falling, & Recovery Phases

By: HWC, Views: 6075

In this tutorial, we will review the phases of an action potential measured from a small area of a neuron's membrane. The action potential can be divided into five phases: the resting potential, threshold, the rising phase, the falling phase, and the recovery phase. When the neuron is at rest,...

Endocrine System Animation

By: Administrator, Views: 940

Vital function of endocrine system: Production and regulation of chemical substances called hormones. Hormones Chemical transmitters released in small amounts and transported via bloodstream to a target organ or other cells. Transfer information and instructions from one set of cells to anot...

How do the different types of chromatography work? (No Audio)

By: HWC, Views: 5958

Chromatography is a term for a variety of techniques in which a mixture of dissolved components is fractionated as it moves through some type of porous matrix. A glass column is filled with beads of an inert matrix. The mixture of proteins to be purified is dissolved in a solution and passed ...

Optic Nerve and Optic Disk Animation (Part 2 of 2)

By: Administrator, Views: 9616

The optic disc or optic nerve head is the point of exit for ganglion cell axons leaving the eye. Because there are no rods or cones overlying the optic disc, it corresponds to a small blind spot in each eye. The ganglion cell axons form the optic nerve after they leave the eye. The optic disc ...

Structure of Amino Acid, Peptide Bonds & Polypeptides

By: HWC, Views: 6105

Here are the molecular formulas of three different amino acids. All amino acids share this backbone. The main difference between every amino acid is the side groups seen here, and these side groups give each of the amino acids their different characteristics. But before we get into that, let's ...