Proteins is made up of a sequence of an amion group, a carboxyl group, a hydrogen atom and a side chain bonded to the central carbon atom.
Answer:A
 
        
             
        
        
        
Answer;
Amino acid side chains have many carboxyl and amino groups.
Explanation; 
-A buffer solution is a solution that resists changes in pH when small quantities of an acid or an alkali are added to it. It is a chemical substance that helps maintain a relatively constant pH in a solution, even in the face of addition of acids or bases.
-Buffering is important in living systems as a means of maintaining a fairly constant internal environment, also known as homeostasis.Small molecules such as bicarbonate and phosphate provide buffering capacity as do other substances, such as hemoglobin and other proteins.
-
Protein buffer systems depend upon proteins, as opposed to nonprotein molecules, to act as buffers and consume small amounts of acid or base. Since amino acids have the capability of reacting with both acid and base, they naturally act as buffers.
 
        
             
        
        
        
Answer:
Una enzima es una sustancia, generalmente una proteína, en la célula de un organismo que acelera las reacciones químicas.
 
Durante el pardeamiento enzimático, una enzima llamada fenolasa y otro compuesto orgánico que se encuentra en las células de la fruta llamados fenoles pasan por una reacción de oxidación cuando se exponen al oxígeno. La fenolasa regula la reacción, convirtiendo los fenoles en melanina. 
Por lo general, las enzimas de la fruta están encerradas en tejido. Las enzimas están metidas en sus células, trabajando para madurar la fruta. Pero cuando esas células se descomponen, ya sea por una causa externa como si alguien muerde o corta la fruta o por causas naturales como el envejecimiento, las enzimas se liberan y entran en contacto con el oxígeno, lo que desencadena la reacción química y hace que la fruta se vuelva marrón.
 
        
             
        
        
        
Answer; 
This is because most likely some time a ago there use to be Ammonites living there and as they died there, they got fossilized.
Explanation; 
-Fossils of a marine animal called Ammonite are found in large numbers in the Kali Gandaki river in Nepal. Ammonites were sea animals having shells - either straight or coiled. When the Tethys sea disappeared, they were caught in the shale layers of clay and transformed into fossils. This is one of the proofs that the Himalayas were indeed once under water.