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Which of the following classes of biological molecules includes enzymes?

A. Lipids

B. Vitamins

C. Carbohydrates

D. Proteins

Answer Explanation:

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.

Therefore, the Correct Answer is D.

More Questions on TEAS 7 Science

  • Q #1: Which of the following classes of biological molecules includes enzymes?

    A. Lipids

    B. Vitamins

    C. Carbohydrates

    D. Proteins

    Answer Explanation

    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.

  • Q #2: If a portion of a strand of DNA bases reads 3’TCGATCGCA 5’, what would the sequence of bases on the complementary strand read?

    A. 5’AGCTAGCGT 3’

    B. 3’ TCGUTCGCU 5’

    C. 3’ AGCTAGCGT 5’

    D. 5’ GGUTACTAC 3’

    Answer Explanation

    The sequence of bases on the complementary strand of DNA would read 5’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:
     

  • Q #3: Which of the following is an efferent neuron that is responsible for releasing a neurotransmiter that stimulates a muscle cell to contract?

    A. Motor neuron

    B. Interneuron

    C. Sensory neuron

    D. Neuroglia

    Answer Explanation

    An efferent neuron that is responsible for releasing a neurotransmitter that stimulates a muscle cell to contract is a motor neuron ². Motor neurons carry signals from the brain to the peripheral nervous system in order to initiate an action. The neurotransmitter acetylcholine (ACh) is released by motor neurons at the neuromuscular junction in skeletal muscle, causing the muscle to contract ³.

    The other options are incorrect because they do not accurately describe the type of neuron responsible for releasing a neurotransmitter that stimulates a muscle cell to contract. Interneurons are found within the central nervous system and facilitate communication between sensory and motor neurons. Sensory neurons carry information from sensory receptors to the central nervous system. Neuroglia are support cells for neurons and do not transmit nerve impulses.

  • Q #4: The triple point of a substance is the temperature and pressure at which the substance exists as which of the following?

    A. Simultaneously in sol, gel, and plasma phases

    B. As a gel with solid and liquid trapped in gas

    C. As a sol with gas and solid trapped in liquid

    D. Simultaneously in solid, liquid, and gas phases

    Answer Explanation

    The triple point of a substance is the temperature and pressure at which the substance exists simultaneously in solid, liquid, and gas phases ¹. In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.

    The other options are not correct because they do not accurately describe the triple point of a substance. Sol, gel, and plasma are not phases that coexist at the triple.

  • Q #5: For which of the following reasons does a chloride ion have a negative charge?

    A. It gained an electron

    B. It lost an electron.

    C. It lost a proton.

    D. It gained a proton.

    Answer Explanation

    A chloride ion has a negative charge because it gained an electron. When an atom gains an electron, it becomes negatively charged because it now has more electrons than protons. In the case of a chloride ion, the neutral chlorine atom gains an electron to become a negatively charged chloride ion.

    The other options are incorrect because they do not result in a negative charge. Losing an electron would result in a positive charge. Losing or gaining a proton would change the identity of the atom and is not related to the formation of a chloride ion.

  • Q #6: Which of the following structures is an exocrine gland?

    A. Pineal gland

    B. Parathyroid gland

    C. Parotid gland

    D. Pituitary gland

    Answer Explanation

    The parotid gland is an exocrine gland that secretes saliva into the mouth. Exocrine glands secrete their products into ducts that carry the secretions to the body's surface or into body cavities. The other options are endocrine glands, which secrete hormones directly into the bloodstream. The pineal gland secretes melatonin, the parathyroid glands secrete parathyroid hormone, and the pituitary gland secretes several hormones that regulate various bodily functions.

  • Q #7: A study found two processes, Process A and Process B, to be correlated. Which of the following is true for these processes?    

    A. The study indicates that Process A causes Process B.

    B. The study cannot indicate whether Process A and B have a positive relationship.

    C. The study does not indicate a causal relationship between the processes.

    D. The study cannot indicate whether Process A and B have a negative relationship.

    Answer Explanation

    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.

     

  • Q #8: Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?

    A. Oxygen

    B. Carbon monoxide

    C. Carbon dioxide

    D. Carbonic acid

    Answer Explanation

    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.

  • Q #9: Which of the following tools can be used to measure the turbidity of a liquid by measuring the transmission of light through the sample?

    A. Centrifuge

    B. Spectrophotometer

    C. Microdensitometer

    D. Electrophorometer

    Answer Explanation

    The correct answer is b. Spectrophotometer. A spectrophotometer is a tool that can be used to measure the turbidity of a liquid by measuring the transmission of light through the sample. Turbidity is a measure of the cloudiness or haziness of a liquid caused by the presence of suspended particles. A spectrophotometer measures the amount of light that passes through the sample and compares it to the amount of light that passes through a reference sample to determine the turbidity.

    a. A centrifuge is a tool used to separate components of a mixture based on their densities, not to measure

    turbidity.

    c. A microdensitometer is a tool used to measure the optical density of an image, not to measure turbidity.

    d. An electrophorometer is a tool used to separate charged particles based on their size and charge, not to measure turbidity.

  • Q #10: Which of the following summarizes a change that takes place as a solid turns to a liquid?

    A. Particles have a decrease in mobility.

    B. Particles become less ordered.

    C. Particles move closer together.

    D. Intermolecular forces between particles become stronger.

    Answer Explanation

    A change that takes place as a solid turns to a liquid is that particles become less ordered ¹. When a solid is heated, its particles gain energy and begin to vibrate more rapidly ². As the temperature increases, the particles gain enough energy to overcome the forces holding them in place and begin to move more freely

    ². This results in a loss of order as the solid melts and becomes a liquid.

    The other options are not correct because they do not accurately describe a change that takes place as a solid turns to a liquid. Particles do not have a decrease in mobility, move closer together, or experience stronger intermolecular forces between them as a solid turns to a liquid.