Enzymes are catalysts that can be used more than once. If a substance needs to get broken down then it can use the corresponding enzyme to attach itself and break it down into simpler substances. After this is gone, the next substance might come up and attach itself to the enzyme like a lock-and-key model.
Therefore the answer is A) Enzymes accelerate chemical reactions without getting used up in the process.
Answer: Atmospheric Nitrogen is unreactive
Explanation:
The atmosphere is made up of about 80% Nitrogen, 16% oxygen, about 4% carbon dioxide, rare gases etc.
However, the 80% Nitrogen is highly unreactive, and needs to be trapped by competent micro organisms known as nitrogen-fixing bacteria in the root nodules of legumes.
Then, it is converted to several forms like nitrites, nitrates (easily absorbed by plants), ammonia and finally escape to the atmosphere again.
This brief illustration explains the NITROGEN CYCLE, and it is the only means by which plants and animals can use the highly unreactive nitrogen
Answer: <em>The reaction is an example of a metathesis reaction, which involves the exchange of ions between the Pb(NO3)2 and KI. The Pb+2 ends up going after the I- resulting in the formation of PbI2, and the K+ ends up combining with the NO3- forming KNO3.</em>
Explanation:
Nervous muscle action pressure
Answer:
B)attach specifically to host cell receptors
Explanation:
Viral spikes are one of the envelope proteins. These proteins are coded for by viral genes. Viral spikes project from the envelope surface. They are also called peplomers. One of the functions of these spikes is to specifically interact with the receptors present on the surface of the host cell to mediate the attachment of the virus to the host cell surface. Viral spikes and the host cell surface receptors are complementary to allow their specific binding. For example, the spike protein of the SARS-coronavirus bind specifically to the human host cell receptor ACE2.
