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Semidiscontinuous DNA replication

By: HWC, Views: 6294

During DNA replication, one of the two DNA strands, the leading strand, is replicated continuously, or all at once, in the 5' to 3' direction. The other strand, called the lagging strand, is replicated discontinuously, or in pieces, in the 3' to 5' direction. This is necessary because DNA poly...

Properties of water -structure of water and polarity (Ionized and polar compounds)

By: HWC, Views: 6829

■ Water transports most of the molecules in the body. ■ The structure of a water molecule allows it to dissolve other molecules. ■ Shared electrons spend more time near the oxygen atom. ■ Oxygen end has a partial negative charge. ■ Hydrogen ends have a partial positive charge....

Protein digestion - stomach & small intestine

By: HWC, Views: 6090

• Protein digestion occurs in the stomach and small intestine. • The stomach enzyme pepsin initiates the process. • Pancreatic and intestinal brush border enzymes complete the digestive process. • In the stomach, pepsin is created from pepsinogen in the presence of pH-lowering hyd...

Condensation and Hydrolysis Animation

By: HWC, Views: 537

A condensation reaction joins two molecules together to form one larger molecule. An enzyme removes a hydroxyl group from one molecule and a hydrogen atom from another, then speeds the formation of a bond between the two molecules at their exposed sites. Typically the discarded atoms join t...

Digestive chemicals - types & enzymes

By: HWC, Views: 6627

• Chemical digestion breaks down food as it moves through the digestive tract. • Using enzymes and other digestive chemicals, the process reduces food particles into nutrient molecules that can be absorbed. • Most chemical digestion is done by the actions of digestive enzymes. • O...

Hormonal regulation of blood pressure - RAA system

By: HWC, Views: 7113

■ Long-term regulation of MABP is under hormonal control. • Hormones that affect blood pressure and volume: the renin-angiotensin-aldosterone (RAA) system, antidiuretic hormone (ADM), and atrial natriuretic peptide (ANP). ■ Most important hormonal regulator of MABP. Activated by drop in...

Bond types - Atomic structure and basis of bonds

By: HWC, Views: 7042

• Chemical bonds are fundamental to the structure and function of many types of molecules, such as proteins, carbohydrates, lipids, nucleic acids, gases, salts and water. ■ These molecules are composed of atoms that are held together by three different types of bonds. • The three types ...

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

By: HWC, Views: 6297

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...

Structure of Amino Acid, Peptide Bonds & Polypeptides

By: HWC, Views: 6142

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 ...