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:
c. Two sister chromatids did not separate into the proper daughter cells during anaphase.
Explanation:
The observed cell is undergoing mitosis which does not include separation of homologous chromosomes. During anaphase of mitosis, two sister chromatids of each chromosome separate from each other. They move to opposite poles. This results in equal distribution of two complete sets of chromosomes to each daughter cell.
However, the failure of two sister chromatids of a chromosome during anaphase would lead to the formation of two abnormal daughter cells. One of the daughter cells would have one extra chromosome (2n+1) while the other would lack one chromosome from the diploid set (2n-1).
Pesticide use can be very harmful beacause too much of them can cause the crops to go bad, and kill bees which help spread pollen and enhance the crops.
Answer:
ANSWER : NICHE
Explanation:
The particular role of a species or organism in its comprising ecosystem is termed as niche. Niche refers to every way that a specie interacts with its environment included both the biotic components as well as the abiotic components. Niche describes how well an organism is adapted for a particular environment. It tells us how well a species is for competing for food and other resources in that environment and how it is better for that environment.
Answer:
The given blank can be filled with operator.
Explanation:
The proteins that assist in turning on or turning off the function of a specific gene by getting combined with certain sections of the DNA are known as transcription factors. The transcription factors that activate the transcription of a specific gene are known as activators, while that prevents transcription and is termed as repressors.
A repressor can be an RNA or a DNA binding protein, which prevents the articulation of genes by getting combined with the operator. A repressor, which binds with DNA prevents RNA polymerase from getting combined with the promoter, which further inhibits the transcription of the genes into mRNA.