Protein structure is the three-dimensional arrangement of atoms in a protein molecule. Proteins are polymers — specifically polypeptides — formed from sequences of amino acids, the monomers of the polymer. A single amino acid monomer may also be called a residue (chemistry) indicating a repeating unit of a polymer. Proteins form by amino acids undergoing condensation reactions, in which the amino acids lose one water molecule per reaction in order to attach to one another with a peptide bond. By convention, a chain under 30 amino acids is often identified as a peptide, rather than a protein.[1] To be able to perform their biological function, proteins fold into one or more specific spatial conformations driven by a number of non-covalent interactions such as hydrogen bonding, ionic interactions, Van der Waals forces, and hydrophobic packing. To understand the functions of proteins at a molecular level, it is often necessary to determine their three-dimensional structure. This is the topic of the scientific field of structural biology, which employs techniques such as X-ray crystallography, NMR spectroscopy, and dual polarisation interferometry to determine the structure of proteins.
Protein structures range in size from tens to several thousand amino acids.[2] By physical size, proteins are classified as nanoparticles, between 1–100 nm. Very large aggregates can be formed from protein subunits. For example, many thousands of actin molecules assemble into a microfilament.
A protein may undergo reversible structural changes in performing its biological function. The alternative structures of the same protein are referred to as different conformational isomers, or simply, conformations, and transitions between them are called conformational changes.
Answer:
1. <u>The height of bean plants</u> depends on the amount of water they recieve.
2. The higher the temerature of the air in the oven, <u>the (speed of which) a cake will bake.</u>
3. Lemon trees receiving the most water produced the most<u> lemons (amount)</u>
4. An investigation found that more <u>bushels of potatoes</u> were <u>produced</u> when the soil was fertalized (amount) more.
5. The amount of <u>pollution</u> produces by cars was measured for cars using gasoline containing different amounts of lead.
Explanation:
The independent variable is what you change and the <u>dependent</u> variable is what is being measured. It is like cause and effect.
(sorry this is my first answer apologizes for any mistakes)
<h3><u>Answer;</u></h3>
b). Activation of an upstream guanine nucleotide exchange factor
<h3><u>Explanation</u>;</h3>
- <em><u>When a ligand activates the G protein-coupled receptor, it induces a conformational change in the receptor that allows the receptor to function as a guanine nucleotide exchange factor (GEF) that exchanges GDP for GTPthus turning the G protein-coupled receptor on.</u></em>
- The activated G-protein then dissociates into an alpha (G-alpha) and a beta-gamma complex.
