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Energy sources - types

By: HWC, Views: 6891

• The amount of ATP stored in a skeletal muscle cell can only provide muscular activity for two to three seconds. • Muscle cells must be able to generate additional molecules of ATP to continue contracting. • Muscle cells can generate ATP from several processes: • Phosphogen syste...

Factors that affect conduction rates (myelination, axon diameter & temperature)

By: HWC, Views: 6757

• Several factors determine the rate of conduction of action potentials: • Myelination • Axon diameter • Temperature • The step-by-step depolarization of an axon is called continuous conduction and occurs along unmyelinated axons. • Neurons in the PNS have many axons that ...

Major Elements in Biological Molecules: Lipids

By: HWC, Views: 5923

A triglyceride (also called triacylglycerol) is composed of three fatty acid molecules and one glycerol molecule. The fatty acids attach to the glycerol molecule by a covalent ester bond. The long hydrocarbon chain of each fatty acid makes the triglyceride molecule nonpolar and hydrophobic. Pa...

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...

Introduction to Pre-eclampsia

By: Administrator, Views: 9729

Pre-eclampsia (PE) is a disorder of pregnancy characterized by the onset of high blood pressure and often a significant amount of protein in the urine. When it arises, the condition begins after 20 weeks of pregnancy. In severe disease there may be red blood cell breakdown, a low blood platelet c...

What Are Carbohydrates? Importance of Carbs & High Carb Food

By: HWC, Views: 6716

We hear a lot about carbohydrates in the news. Everybody seems to be on a low-carb diet. The news media often has stories on this diet fad, and companies are busy producing products with reduced carbohydrates. What's this fascination with carbohydrates? In a word: "Diet." The fact is that carb...

Embryonic development - Week 3

By: HWC, Views: 6705

Week 3 (gastrulation) • Three primary germ layers are formed which provide cells for organ formation in the following months. • These germ cell layers are formed by a process known as gastrulation, which involves rearranging epiblast cells. • As cells from the epiblast migrate, a fain...

Chromosome structural organization/ Mechanisms for chromosome movement Animation

By: HWC, Views: 2804

How the chromosome is organized. At metaphase, the chromosomes are duplicated and are at their most condensed. In each chromosome, two identical sister chromatids are held together at a constricted region called the centromere. When a chromosome is condensed, interactions among chromosomal ...

Structure of Amino Acid, Peptide Bonds & Polypeptides

By: HWC, Views: 6141

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 ...