Which of the following classes of biological molecules includes enzymes?

Most of the carbon dioxide from the blood moves into the alveoli by diffusion down a concentration gradient ¹. Carbon dioxide is always carried in the blood and is released into alveolar air during expiration ¹. Respiratory gases move from higher concentration to lower concentration ¹. In alveolar air, when carbon dioxide is less than in blood, carbon dioxide is released ¹.

The other options are incorrect because they do not accurately describe the process by which most of the carbon dioxide from the blood moves into the alveoli. Passive transport using carrier proteins, active transport using energy, and conversion to carbon monoxide is not the processes responsible for moving most of the carbon dioxide from the blood into the alveoli.

The correct answer is b. Peptide bonds. Enzymes are proteins, and proteins are made up of amino acid monomers linked together by peptide bonds. A peptide bond is a covalent bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid.

a. Ester bonds are covalent bonds that form between a carboxylic acid and an alcohol.

c. Phosphodiester bonds are covalent bonds that form between a phosphate group and two hydroxyl

groups.

d. Glycosidic bonds are covalent bonds that form between two monosaccharides.

The correct answer is d. Carbonic acid. When blood pH rises, carbonic acid can donate H+ ions to act as a buffer and help maintain the pH within a normal range. Carbonic acid is formed when carbon dioxide dissolves in water and reacts with it.

A. Oxygen is not responsible for donating H+ ions to act as a buffer when blood pH rises.

B. Carbon monoxide is a toxic gas that does not play a role in buffering blood pH.

C. Carbon dioxide can dissolve in water to form carbonic acid, which can then donate H+ ions to act as a buffer.

The correct answer is c.

The study does not indicate a causal relationship between the processes. A correlation between two processes means that there is a statistical relationship between them, but it does not necessarily imply causation. In other words, just because two processes are correlated does not mean that one causes the other.

b.The study does not indicate that Process A causes Process B.

b.The study can indicate whether Process A and B have a positive relationship if the correlation is positive.

d. The study can indicate whether Process A and B have a negative relationship if the correlation is negative.

The best reason for the prolonged preservation of the body is that it was frozen in the cold temperature of the Alps shortly after death and remained frozen until it was found. Freezing can preserve a body by slowing down or stopping the decomposition process.

The other options are not as likely to have caused prolonged preservation.

Ultraviolet rays can damage molecules rather than preserve them. Toxins in food would not necessarily kill all bacteria that could cause decomposition. Blood loss from an arrow wound would not necessarily clear all enzymes that could break down tissue.

The sequence of bases on the complementary strand of DNA would read5’AGCTAGCGT 3’ (Choice A). In DNA, the nitrogenous bases adenine (A) and thymine (T) pair together, and cytosine (C) and guanine (G) pair together. The complementary strand is also antiparallel to the original strand, meaning that it runs in the opposite direction with the 5' end matching up with the 3' end of the original strand.

The other options do not accurately represent the complementary sequence of bases or the antiparallel orientation of the strands.

BONUS:

The doctor refuses to prescribe antibiotics to the patient because the illness is caused by a virus. The common cold is a viral infection of the upper respiratory tract. Antibiotics are not effective against viral infections and are only used to treat bacterial infections.

The other options are not correct because they do not accurately describe the cause of the common cold and sore throat. Fungus, protist, and bacteria are not the pathogens responsible for causing the common cold.

A genetic mutation that results in uncontrolled division of a single cell within the body describes cancer ¹. Cancer is a disease of uncontrolled cell division ¹. Its development and progression are usually linked to a series of changes in the activity of cell cycle regulators ¹. In most cases, these changes in activity are due to mutations in the genes that encode cell cycle regulator proteins ¹.

The other options are not correct because they do not accurately describe a genetic mutation that results in uncontrolled division of a single cell within the body. Gene therapy, stem cells, and translation are not processes that result in uncontrolled cell division.

Enzymes are a type of protein that catalyze chemical reactions in the body. Proteins are one of the four main classes of biological molecules, along with lipids, carbohydrates, and nucleic acids.

The other options are not classes of biological molecules that include enzymes.Lipids are a class of molecules that includes fats and oils, vitamins are organic compounds that are essential for normal growth and nutrition, and carbohydrates are a class of molecules that includes sugars and starches.

The correct answer is d. A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4. The pH scale is a logarithmic scale, which means that each change of one pH unit represents a tenfold change in the hydrogen-ion concentration. A substance with a pH of 3 has a hydrogen-ion concentration that is 10 times greater than that of a substance with a pH of 4.

A. A substance with a pH of 3 is not two times more alkaline than a substance with a pH of 4.

B. A substance with a pH of 3 is not 10 times more alkaline than a substance with a pH of 4.

C. A substance with a pH of 3 is not two times more acidic than a substance with a pH of 4.