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Results for: 'polypeptide chain'

The life cycle of protein

By: HWC, Views: 4754

The life cycle of a typical protein begins with its synthesis on a ribosome. As the polypeptide chain grows, molecules of a chaperone protein bind along its length. This prevents misfolding of the nascent polypeptide. ATP binding causes chaperone release. For most proteins, the polypeptide th...

Structure of a Ribosome

By: HWC, Views: 2124

The structure and function of the mammalian ribosome. The mammalian ribosome consists of two subunits, one small and one large. Each subunit is assembled in the nucleus from rRNA and structural proteins. Once assembled, the ribosomal subunits are shipped separately to the cytoplasm. ...

The 4 steps of translation Animation

By: HWC, Views: 1217

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...

Protein Secondary and Tertiary Structures - Animation

By: HWC, Views: 1483

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 r...

Protein Structure - Primary, Secondary, Tertiary and Quaternary

By: HWC, Views: 5232

A protein's first order structure, or primary structure, begins with the amino acid sequence of the polypeptide chain. The 20 different amino acids can be arranged in an infinite number of sequences. For example, the hormone insulin, which regulates the uptake of glucose from the blood into ce...


By: HWC, Views: 4417

Living things must accomplish a great number of tasks just to get through a day, and these tasks are accomplished by a diverse range of biological molecules. In the range of tasks that molecules accomplish, however, proteins reign supreme. Almost every chemical reaction that takes place in living...

Oxygen transport - methods and oxyhemoglobin

By: HWC, Views: 5156

• The blood is the medium used for gas transport throughout the body. • Oxygen is only available in the lungs. Because the partial pressure of oxygen is higher in the alveoli than in the blood, oxygen diffuses into the blood and is transported to systemic cells. • At the tissues the par...

Major Elements in Biological Molecules: Proteins

By: HWC, Views: 4757

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...

Anatomy and Chemical Makeup of a Single Hair (Animation)

By: HWC, Views: 3672

The hair's outer cuticle surrounds hair cells filled with tough keratin macrofibrils. Each macrofibril consists of smaller microfibrils. A microfibril is made up of three keratin polypeptide chains. The chains are linked together by disulfide bonds. A hair consists of keratin chains held...