Yes. In order for the body to use food, the food must be broken down into it's most basic elements. Complex carbohydrates are broken into simple carbohydrates, proteins are broken down into amino acids and fats are broken down into fatty acids. Some of this break down takes place because of the acids in your stomach, but enzymes in the stomach and mouth are required to further dismantle food into usable nutreints.
Speeds up the rates of chemical reactions by providing energy for the cell to use. Thus, the cell is not working as hard to perform the task. You need enzymes to survive. That is one of the reasons why a high temperature fever is a problem, the enzymes that help to keep you alive are denaturing (basically being rendered useless) and without them you cannot live.
Yes. Enzymes are pretty much known as catalysts, and the definition of a catalyst is "a substance that increases the rate of a chemical reaction, without being consumed or produced by the reaction." So thus we see the enzyme being active in a reaction but not destroyed. There are exceptions to this, though. If an enzyme is kept in hot, unfavorable temperatures, it will change shape or become "denatured" and may become useless in a very short time.
Restiriction enzymes, or endonucleases, splice (cut) apart two different sites of the nucleotide sequence on foreign DNA resulting in two different pieces of DNA for a gene of interest to be inserted. This usually occurs in bacteria such as E. coli and such. Once the two cuts have been made (one at 5' and one at 3') there remains the open ends of the DNA called 'sticky ends'. THis is where the gene of interest is inserted.
enzyme works as a catalyst before and after the reaction it is preserved
When the pH level rises, the enzyme's bonds become weakened, changing the enzyme's structure and disabling its function (so its substrates can't enter its active site). Enzymes, like all proteins, are folded into three-dimensional shapes (called tertiary structure). Their structures are determined by their amino acid sequences and the conditions of the solution they're in. The acidity of a solution can affect the tertiary structure of the protein, making it more or less accessible to the substrates or ligands(molecules that affect enzyme activity but are not processed by the enzyme). In most cells, enzymes acting in the cytosol and mitochondria have pH optima of around 7.2 (physiological pH). However, some enzymes in these compartments actually work better at lower pH, which occurs when the cells are stressed. The vacuole and apoplastic space (between plasma membrane and cell wall) of plant cells is much more acidic, therefore enzymes acting there have pH optima between 3-5. In the human digestive tract, there are enzymes operating at basic pH (mouth and intestine) and highly acidic pH (stomach). So the effect of pH depends on the "native" conditions that the enzyme is optimized to use.
large amounts of heat can denature enzymes and render them useless
It's a part of a satellite system. -- but this statement is nearly useless without any additional information.
appendix
Not necessarily "useless", but he is less powerful without Kyuubi.
The part of the digestive system that has no digestive function is called the esophagus. The esophagus is also known as the food pipe.
Electricity is not useless; it is a fundamental component of modern life, powering homes, businesses, transportation, and technology. Without electricity, many aspects of daily life would be severely limited or impossible.
completely useless.
This is because on instruments, there might be harmful bacteria. These (as do any organism) function by having enzymes so catalyze critical reactions in a cell. When these enzymes (and all other proteins) reach a certain temperature, they are denatured (in other words, rendered useless). Without these enzymes, the bacteria dies and the instruments are now safe to use again (and won't infect anybody else).
AIR!
When new neurons grow the connection with others is important. Without this connects, new thought patterns are not possible. Think about it like your sing a laptop without it being plugged in is a useless act.
useless, without use, good for nothing
A very useless motherboard