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All substances used or produced by organisms are composed of organic molecules.

ID: 223731 • Letter: A

Question

All substances used or produced by organisms are composed of organic molecules. True or Fals

A solution of which would be expected to have the highest pH? A)Citric acid B)hydrochloric acid C)sulfuric acid D)distilled water E)A solution of sodium hydroxide(NaOH)

Which of the following is not made up of protein or does not contain protein? A)cell membranes B)enzymes C)antibodies D)hemoglobin E)DNA and RNA

When exposed to abnormal pH or temperature, the primary structure of proteins would be much more stable than the tertiary structure. A)True B)False

Which is the variable portion of a nucleic acid? A)a base such as adenine B)a phosphate C)5-carbon sugar D)amino acid E)disulfide bond

Which two of the following would not be considered a covalent modification of a protein? A)attachment of a carbohydrate B)attachment of a phospholipid C)removal of a signal sequence D)reversable change in shape due to binding of a ligand E)reduction in enzymatic activity at suboptimal temperature or pH

Explanation / Answer

All substances used or produced by organisms are composed of organic molecules. True or False

this statement is false. As organism need metals which act as cofactor in enzymatic activity and inorganic substances like phosphate

A solution of which would be expected to have the highest pH? A)Citric acid B)hydrochloric acid C)sulfuric acid D)distilled water E)A solution of sodium hydroxide(NaOH)

Highest pH means that one of the given substance should be basic. From the given option NaOH is the only basic. So option E i.e. A solution of sodium hydroxide(NaOH) is the correct option

Which of the following is not made up of protein or does not contain protein? A)cell membranes B)enzymes C)antibodies D) hemoglobin E)DNA and RNA

Answer - RNA and DNA are made up of nitrogen bases, Ribose sugar and inorganic phosphate which are not amino acids which are basic unit of proteins. So answer is option E - DNA and RNA

When exposed to abnormal pH or temperature, the primary structure of proteins would be much more stable than the tertiary structure. A)True B)False

The tertiary structure of the protein is stabilised by various linkage like H-bond, van der Waals interaction, disulphide bridges, the salt bridge which is sensitive to change in pH. or temperature. In case of primary structure only one type of interaction is present that is peptide bond between the amino acid. When exposed to abnormal pH or temperature, the primary structure of proteins would be much more stable than the tertiary structure statement is True

Which is the variable portion of a nucleic acid? A)a base such as adenine B)a phosphate C)5-carbon sugar D)amino acid E)disulfide bond

RNA and DNA are made up of nitrogen bases, Ribose sugar and inorganic phosphate. There are four nitrogen bases present in the each type of nucleic acid which are the only components that varies.

So the correct option is option A)a base such as adenine

Which two of the following would not be considered a covalent modification of a protein? A)attachment of a carbohydrate B)attachment of a phospholipid C)removal of a signal sequence D)reversable change in shape due to binding of a ligand E)reduction in enzymatic activity at suboptimal temperature or pH