Enzymes are proteins so why don't proteins break themselves down? (Why are enzymes needed?)

Explanation:

Enzymes are biological catalysts. They speed up the rate of reaction (without themselves being chemically changed at the end of reactions) Enzymes only speeds up the rate of reactions they don't break down stuff

in addition, proteins are broken down in chemical reactions. enzymes being proteins of course will get broken down as well but they do not break themselves down since they never will break anything down

enzymes are needed as they lower activation energy (activation energy is often supplied in the form of heat but for some reactions to take place, the heat energy required may be too hot for a body to handle (such as a human body) this will cause negative effects to the reactants and the body. as a result, enzymes are the ones who help to reduce such happenings) and speed up rate of chemical reactions. by lowering activation energy, less heat is needed to be supplied to the reactants for them to react and hence less energy is required (aka in most cases less heat is required)

hope that gives you a better understanding on enzymes :)

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.