Answer:
Alpha helixes:
- form long thin structures important for transmembrane proteins
- have a rigid spring like structure around a central axis
Beta sheets:
- Keep their shape due to hydrogen bonds between adjacent polypeptides chains
- have a flat zig zag like structure
Explanation:
Alpha helices and beta pleated sheets are two types of secondary structure found in proteins.
Alpha helix: In this structure, the polypeptide backbone is tightly wound around an imaginary central axis drawn longitudinally through the center with the R groups of the amino acids protruding outward from the helical backbone. This structure looks like a spring and could either be a left-handed or right-handed helix, though the left-handed helix has not been observed in proteins. Each turn of the helix includes about 3.6 amino acid residues.
The alpha helix is stabilized by a hydrogen bond between the hydrogen atom attached to the electronegative nitrogen atom of a peptide linkage and the electronegative carbonyl oxygen atom of the fourth amino acid on the amino-terminal side of that peptide bond.
Alpha-helices due to their structure, are the most common transmembrane proteins- protein structure element that crosses biological membranes.
Beta sheets: In the beta conformation, the backbone of the polypeptide chain is extended into a zigzag structure. The zigzag polypeptide chain can be arranged side by side to form a structure resembling a series of pleats known as beta sheets. Hydrogen bonds formed between adjacent segments of the polypeptide chain functions to stabilize the structure.
The beta comformation in the form of turns is common in globular proteins.
Answer : The enthalpy of formation of is, -812.4 kJ/mole
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The formation of will be,
The intermediate balanced chemical reaction will be,
(1)
(2)
(3)
(4)
Now adding all the equations, we get the expression for enthalpy of formation of will be,
Therefore, the enthalpy of formation of is, -812.4 kJ/mole
Answer:
A
Explanation:
'herd behavior' helps understand the question for the answer
Independent: Number of passengers
Dependent: Distance traveled in cm