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Contraction cycle of a sarcomere

By: HWC, Views: 7176

• A single nervous signal releases Ca2+ ions into the sarcoplasm and initiates the contraction cycle. step 1. ATP hydrolysis • ATP provides the to move myosin molecules back into the energized configuration necessary to perform the power stroke. Step 2. Crossbridge attachment • Myosin...

Hemoglobin's affinity with oxygen - carbon dioxide, temperature and bisphosphoglycerate (BPG)

By: HWC, Views: 6791

• The carbon dioxide gas is temporarily converted to carbonic acid in red blood cells by the enzyme carbonic anhydrase, and then further converted to hydrogen and bicarbonate ions. • The result of increased carbon dioxide is decreased pH causing the Bohr effect. • Elevated carbon dioxid...

Cataract

By: Administrator, Views: 9489

A cataract is a clouding of the lens in the eye which leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble with bright lights, and trouble seeing at night. This may re...

Proteins Defined, Hierarchy & Composition of Cells

By: HWC, Views: 6155

Proteins are long chains of amino acids linked together by peptide bonds. Together with the other three biological macromolecules—carbohydrates, lipids, and nucleic acids—proteins are the building blocks of cells. Proteins are the most complex and abundant biological macromolecules in cel...

Introduction to Autism

By: Administrator, Views: 10064

Autism is a developmental disorder characterized by difficulties with social interaction and communication, and by restricted and repetitive behavior. Parents usually notice signs during the first three years of their child's life. These signs often develop gradually, though some children with au...

Predator- prey competition and symbiosis

By: HWC, Views: 6481

Predator-prey relationships occur when one species, the predator, kills and eats an organism of another species, the prey. This graph shows the cyclical nature of predator-prey relationships, in this case among populations of Canada lynx and snowshoe rabbits. If predation is without some li...

Simple and Double Sugar

By: HWC, Views: 6482

Here are the molecular structures of three simple sugars: glucose, ribose, and fructose. Look at these simple sugars and identify what characteristics they all share. As you can see, all of the carbohydrates have carbon, hydrogen, and oxygen in a ratio of 1:2:1 and there is always a double bo...

Nervous pathway to the Neuromuscular (NMJ)

By: HWC, Views: 7183

• A nervous impulse, also called an action potential, starts from the brain or spinal cord to signal skeletal muscle cell contraction. Action potentials continue along a motor neuron to the muscle cell. • The signal to contract must cross a synapse - the neuromuscular junction (NMJ) - betwe...

Enzyme structure - Properties of enzymes

By: HWC, Views: 6603

■ Enzymes are proteins that catalyze reactions. ■ Some enzymes have two parts: a protein or apoenzyme and a non-protein or cofactor. ■ Cofactor can be a metal ion or another organic molecule called a coenzyme. ■ Coenzymes often come from vitamins. ■ Cofactors affect the shape of...