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:
accepting electrons at the end of the electron transport chain.
Explanation:
Answer:Mechanical digestion physically breaks down food, like when teeth macerate food into a bolus. The stomach contracts and relaxes in a churning motion. ... Chemical digestion occurs when the bonds within larger food molecules are broken, creating smaller molecules that the body can use.May 30, 2017
Explanation:
The offspring that will be produced in the cross would have tortoiseshell fur.
<h3>X-linked traits</h3>
In cats, the male is XY while the female is XX.
Assuming that black fur is caused by the allele B and the orange fur is caused by A
A black female will have the genotype 
An orange male will have the genotype 
Crossing the two: x
Offspring: 
, 
, , and
= tortoiseshell fur female
= tortoiseshell fur male
More on x-linked traits can be found here: brainly.com/question/11189684
Answer:
A) The radial orientation of cellulose microfibrils in the cell walls of guard cells causes them to bow outward and open when the stomatal pore when turgid.
Explanation:
Stomata are pores on the surface of leaves that work as valves controlling the gas exchange in plants; they are bordered by a pair of curved guarded cells in charge of opening and closing by increasing or decreasing the stomatal pore area.
Guard cells walls structure consist of a combination of stiff cellulose microfibrils oriented along the circumference of the cells and a softer matrix material which makes it possible for stomata pore to open by increasing water pressure (turgor).
Option B states that when guard cells become turgid, they close the stomata. This is a false statement as we explained before.
Option C states that light (known stimulant for opening stomata) causes guard cells to become flaccid which is also false. Guard cells become turgid in order to open the stomatal pore.
Option A is correct.
