Answer:
The initial step in the formation of an aminoacyl-tRNA is activation of the amino acid by reaction with ATP
Explanation:
In protein synthesis, the first step involves the formation of an aminoacyl-tRNA. This reaction is catalyzed by the the Mg²⁺-dependent enzymes known as aminoacyl t-RNA synthetases and occurs in two steps.
The first step of the reaction of the formation of an aminoacyl-tRNA is the activation of the amino acid by the attachment of an AMP molecule formed from the hydrolysis of ATP to AMP and pyrophosphate. The aminoacyl adenylate intermediate is bound to the enzyme in this initial step. Subsequently, in the second step of the activation of the amino acid, the aminoacyl adenylate intermediate is then transferred to its specific tRNA. The pyrophosphate formed in the first step is hydrolyzed to 2 phosphate molecules by a pyrophosphatase.
The overall reaction step is illustrated below:
Amino acid + tRNA + ATP -----> aminoacyl-tRNA +AMP + 2Pi
B
Energy is needed to move sugar from low to high concentration while using a membrane protein.
Explanation:
The reason that energy is needed in this process is that the movement of the molecules is moving up the concentration gradient. This means decreased entropy and increasing Gibbs's free energy.
This is not a spontaneous process and therefore energy input is required. It is called active transport. This is why ATP energy is used to power the process. Atp enables the transmembrane proteins to change conformation and transport the sugar molecules into the cell.
In facilitated diffusion, while the molecules are facilitated by membrane proteins, no energy is input because the molecules are still traveling down the concentration gradient.
Learn More:
For more on active transport check out;
brainly.com/question/1046994
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