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Protein Structure - Primary, Secondary, Tertiary and Quaternary

By: HWC, Views: 6632

A protein's first order structure, or primary structure, begins with the amino acid sequence of the polypeptide chain. The 20 different amino acids can be arranged in an infinite number of sequences. For example, the hormone insulin, which regulates the uptake of glucose from the blood into ce...

Hip Animation

By: Administrator, Views: 9417

A hip fracture is a break in the upper quarter of the femur (thigh) bone. The extent of the break depends on the forces that are involved. The type of surgery used to treat a hip fracture is primarily based on the bones and soft tissues affected or on the level of the fracture.

Heart Chambers

By: Administrator, Views: 9714

Circulation of blood through the chambers of the heart Septum divides heart into the right and left heart. Each side contains an upper and lower chamber: Atria, or upper chambers, receive blood. Ventricles, or lower chambers, pump blood. Valves control intake and outflow of blood in chamber...

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

By: HWC, Views: 6085

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,...

The Pressure Flow Model in a Plant

By: HWC, Views: 6009

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...

Ventilation - phases and driving forces

By: HWC, Views: 6635

Respiration is the exchange of gases between the atmosphere, blood, and cells The combination of 3 processes is required for respiration to occur Ventilation (breathing) External (pulmonary) respiration Internal (tissue) respiration The cardiovascular system assists the respiratory system b...

The Vestibular System

By: HWC, Views: 5931

The vestibular system has important sensory and motor functions, contributing to the perception of self-motion, head position, and spatial orientation relative to gravity. The function of the vestibular system can be simplified by remembering some basic terminology of classical mechanics. All ...

Pressure Flow Model Animation

By: HWC, Views: 5844

This apparatus of beakers A and funnels simulates the flow of a sucrose solution in the phloem of a plant. The funnels and connecting tube represent a sieve tube of the phloem. Differentially permeable membranes cap the funnels at the source and sink ends, allowing water, but not sucrose, to cros...

Blood Flow through the Human Heart

By: HWC, Views: 6409

The heart is the pump of the human circulatory system. The left side of the heart has two connected chambers, the left atrium and the left ventricle. The right side of the heart also has two connected chambers, the right atrium and the right ventricle. These two sides, or pumps, of the heart are ...