How do the four main macromolecules work together to support an organism ???

The four main types of macromolecules are proteins, nucleic acids, lipids (fats) and carbohydrates.

Proteins are macromolecules whose building blocks are amino acids. These building blocks (amino acids) are held together by peptide bonds.

Nucleic acids (either DNA or RNA) are macromolecules whose building blocks are nucleotides.

The building blocks of carbohydrates are monosaccharides that are held together by glycosidic bonds.

Lipids (e.g., phospholipids, cholesterol) are a broad category of biomolecules composed of a glycerol backbone attached to long chains of fatty acids.

In conclusion, the four main types of macromolecules are proteins, nucleic acids, lipids (fats) and carbohydrates.

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Carbohydrates

Proteins

Lipids

Nucleic acids

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.