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Structure of Amino Acid, Peptide Bonds & Polypeptides

By: HWC, Views: 7217

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 ...

The Pressure Flow Model in a Plant

By: HWC, Views: 7121

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...

Pressure Flow Model Animation

By: HWC, Views: 7012

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...

Covalent bonds - role in the body

By: HWC, Views: 7722

A covalent bond is formed when atoms share one or more pairs of electrons. This is opposed to an ionic bond, where electrons are actually transferred from one atom to another. Formation • Atoms fill up the outer orbital by sharing electrons. • Two oxygen atoms sharing electrons form on...

Krebs cycle : Formation of acetyl coenzyme A and Electron transport chain

By: HWC, Views: 7824

The oxidation of glucose to produce ATP is cellular respiration. Four sets of reactions are involved: Glycolysis Formation of acetyl coenzyme A Krebs cycle reactions Electron transport chain reactions • The second pathway of glucose catabolism, formation of acetyl coenzyme A, is a transi...

DNA Replication

By: HWC, Views: 4616

DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell.

Insulin (glucose uptake by body cells), glycogenesis and lipogenesis

By: HWC, Views: 7851

Insulin is the regulator that allows the sugar from the foods we eat (be it a piece of cake or a stick of celery) to enter our tissues and become part of the metabolic process. Insulin is made by the Islets of Langerhans, which are found in the pancreas of every person. As we previously mentio...

Peptide Bond Formation Animation

By: HWC, Views: 1558

During protein synthesis, peptide bonds link amino acids together in the order specified by DNA instructions. In this case, the first two amino acids in the protein are methionine and alanine. Here are ball-and-stick models of these amino acids. Peptide bond formation is a type of condensatio...

Energy Flow - Trophic Levels and Food

By: HWC, Views: 7321

All of these relationships between different species are founded on one thing: energy. Organisms get food in order to get energy, which is used by the organism for growth, maintaining health, and reproduction. We can classify the members of a community according to how they obtain food. Produc...