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Secondary and tertiary levels of protein structure Animation

By: HWC, Views: 1796

Amino acid sequence dictates a protein's final shape. The presence of certain amino acids favors a pattern of hydrogen bonding that causes part of the polypeptide chain to coil and twist into an alpha helix. The presence of other amino acids enables hydrogen bonding between strand like re...

Mitochondrial Structure & ETC Protein Complexes (Protein Complexes and Electron Transport)

By: HWC, Views: 7519

The energy carrying molecules, NADH and FADH2, that were generated in glycolysis and the Krebs cycle, now are processed in the mitochondria where their high energy electrons are deposited in an electron chain complex located in the inner mitochondrial membranes. These high-energy electrons now dr...

Protein digestion - stomach & small intestine

By: HWC, Views: 7345

• 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...

Transcription—A molecular view

By: HWC, Views: 3467

Transcription, as related to genomics, is the process of making an RNA copy of a gene's DNA sequence. This copy, called messenger RNA (mRNA), carries the gene's protein information encoded in DNA. During transcription, a DNA molecule is copied into RNA molecules that are then used to translate...

The 4 steps of translation Animation

By: HWC, Views: 3704

Translation is the process of formation of a polypeptide chain according to codon present in mRNA. The four steps of translation are: Activation or charging of tRNA Initiation – recognition of start codon, binding of ribosomal subunits to mRNA and formation of initiation complex with Met-tR...

Hershey Chase Experiments

By: HWC, Views: 5048

Hershey and Chase knew that T4 bacteriophages consist of proteins and DNA. They asked which viral component must enter a bacterial cell to infect it: DNA or protein? They grew viruses with either radioactive sulfur, which labels the viral protein, or radioactive phosphorus, which labels DNA. ...

Peptide Bond Formation Animation

By: HWC, Views: 1678

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...

How do the different types of chromatography work? (No Audio)

By: HWC, Views: 7205

Chromatography is a term for a variety of techniques in which a mixture of dissolved components is fractionated as it moves through some type of porous matrix. A glass column is filled with beads of an inert matrix. The mixture of proteins to be purified is dissolved in a solution and passed ...

Major Elements in Biological Molecules: Proteins

By: HWC, Views: 7308

Proteins are chains of amino acids linked by peptide bonds. The 20 different amino acids used to make all proteins differ only in their side chains, and the properties of these side chains account for the great diversity of protein structure and function. Collagen is an example of how a prote...