The four levels of protein structure are distinguished from one another by the degree of complexity in the polypeptide chain. A single protein molecule may contain one or more of the protein structure types: primary, secondary, tertiary, and quaternary structure. 1. Primary Structure: describes the unique order in which amino acids are linked together to form a protein.
2. Secondary Structure: refers to the coiling or folding of a polypeptide chain that gives the protein its 3-D shape. There are two types of secondary structures observed in proteins. One type is the alpha (α) helix structure. This structure resembles a coiled spring and is secured by hydrogen bonding in the polypeptide chain. The second type of secondary structure in proteins is the beta (β) pleated sheet. This structure appears to be folded or pleated and is held together by hydrogen bonding between polypeptide units of the folded chain that lie adjacent to one another
3. Tertiary Structure: refers to the comprehensive 3-D structure of the polypeptide chain of a protein.
4. Quaternary Structure: is the structure of a protein macromolecule formed by interactions between multiple polypeptide chains. Each polypeptide chain is referred to as a subunit. Proteins with quaternary structure may consist of more than one of the same type of protein subunit.
Most scientists don't used the word law because that implies it is infallible but generally scientific laws and theories are used interchangeably so true.
Answer:
evaporation follows condensation
Deposition by the river replenishes soil in the wetlands with sediment and nutrients illustrates a positive effect that the Nueces River has on the wetlands.
Option: C
Explanation:
A river in its lower course leave the high elevated area and enters into the flat land. In the lower course of the river deposition is the prime work of a river. Estuary, delta are some of the landform that formed in the lower course of a river. Here, Nueces estuary is formed where Nueces river enters into the gulf.
In this gulf a wetland is formed which supports aquatic life and a dwelling place for them and land species also. Here, river deposits all its sediments and replenish the soil of wetland with new sediments and nutrients.
