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A slice of apple left on a table slowly goes brown due to an enzymatic reaction. Dipping the apple slice in lemon juice prevents it from browning Which of the following best explains this result?

A. Lemon juice has enzymes which reverse the browning reaction

B. Lemon juice has a pH which inactivates the enzymes

C. Lemon juice functions to bleach the brown material

D. Lemon juice functions to dilute the brown material

Answer Explanation:

Browning of the apple surface is due to the action of the enzyme polyphenol oxidase. Lemon juice is acidic and lowers the pH of the apple's surface. This inactivates the enzyme polyphenol oxidase, which works best at a neutral pH. This in turn reduces the browning action on the apple.

Therefore, the Correct Answer is B.

More Questions on TEAS 7 Science

  • Q #1: in pea plants, green pod color (6) is dominant to yellow pod color ( A cross was done between a plant with green pods and a plant with yellow pods. Of the resulting offspring 50% had green pods and 50% had yellow pods. Which of the following were the genotypes of both parent plants?

    A. Ggx Gg

    B. GG x gg

    C. Gg x gg

    D. gg x gg

    Answer Explanation

     

     

    G

    g

    g

    Gg

    gg

    g

    Gg

    gg

     

  • Q #2: Which of the following organs removes nitrogenous waste from the body?

    A. Large Intestines

    B. Liver

    C. Kidneys

    D. Gall Bladder

    Answer Explanation

    The kidneys are the primary organs involved in the excretion of nitrogenous wastes. Nitrogenous wastes are mostly products of protein metabolism in the liver. One of the common nitrogenous waste products is urea, which is excreted through the kidneys.

     

  • Q #3: Parasitic worm infestation is hypothesized to be damaging to the host. However, scientists have recently discovered that worm infestation can relieve the effects of certain autoimmune disorders, in which of the following ways should the hypothesis be modified, given the new findings?

    A. Lack of worm infestations is the cause of some autoimmune disorders.

    B. Worm infestation reduces the severity of certain autoimmune disorders

    C. Worm infestation prevents the body from immune malfunction

    D. Worm infestations exacerbate the body's immune reactions

    Answer Explanation

    The new findings can be used to generate a hypothesis to reflect the beneficial aspect of worm infestations in certain autoimmune disorders, indicating that they can help reduce the severity of the condition.