It is the Iris I believe. It controls the diameter and size of the pupil, controlling the amount of light reaching the retina.
A wet gangrene is a medical condition that occurs whenever injury from burns or trauma from a body part is crushed or squeezed which rapidly cuts off blood supply to the affected area causing tissue death and increased the risk of infection. It is called wet because of the pus that is formed. Wet gangrene infection can spread quickly throughout the body and cause life-threatening conditions if not treated quickly,
Gangrene is a condition that occurs whenever body tissues die. It primarily caused by a loss of blood supply due to an illness, infection or injury. Oftentimes, this medical condition occurs in the fingers and limbs. They, however, can occur inside the human body damaging organs and muscles.
Answer:
1) Weathering breaks down and dissolves rocks.
2) Wind and Rain as well as erosion.
3) Gravity, Wind, Water.
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.
<em>Answer:</em>
<em>Phospholipids form the basic structure of a cell membrane, called the lipid bilayer. Scattered in the lipid bilayer are cholesterol molecules, which help to keep the membrane fluid consistent. Membrane proteins are important for transporting substances across the cell membrane</em>
