Question 1

When two monosaccharides are joined together, ________ is formed through ________ synthesis.&#10;A) a disaccharide; hydrolysis&#10;B) a polysaccharide; hydrolysis&#10;C) glucose; condensation&#10;D) a disaccharide; condensation&#10;E) starch; condensation

Accepted Answer

When two monosaccharides are joined together, a disaccharide is formed through condensation synthesis, where a molecule of water is removed to form a glycosidic bond between the two monosaccharides. This is the process that forms disaccharides such as sucrose, lactose, and maltose.

Question 2

Which of the following statements is correct? A) A base is a H⁺ ion donor. B) Pure water is completely neutral and has a pH of 0. C) As the concentration of H⁺goes up, the pH also goes up. D) If the hydroxyl ions outnumber the H⁺ ions, the pH will be less than 7.0. E) Bases reduce the concentration of H⁺ in water.

Accepted Answer

Bases indeed reduce the concentration of H+ ions in water, which is consistent with their property of being proton acceptors in aqueous solutions. This leads to an increase in pH, indicating a more basic solution.

Question 3

If an atom X has an atomic number of 18, then:&#10;A) there are 18 protons.&#10;B) there are 9 protons and 9 electrons.&#10;C) there are 18 neutrons.&#10;D) there are 9 protons and 9 neutrons.&#10;E) it also has a mass number of 18.

Accepted Answer

The atomic number of an atom represents the number of protons in its nucleus. Therefore, if the atomic number of atom X is 18, it must have 18 protons.

Question 4

When one atom donates electrons and another atom accepts those electrons, a(n) ________ bond forms.&#10;A) polar covalent&#10;B) hydrogen bond&#10;C) nonpolar covalent&#10;D) ionic

Accepted Answer

When one atom donates electrons and another atom accepts those electrons, an ionic bond forms. In an ionic bond, one atom loses electrons and becomes a positively charged ion (a cation), while the other atom gains electrons and becomes a negatively charged ion (an anion). The opposite charges attract each other and hold the ions together in a crystal lattice structure.

Question 5

Which of the following is a mismatched pair?&#10;A) electrons: negative charge&#10;B) neutrons: no charge&#10;C) protons: positive charge&#10;D) atomic mass number: protons plus electrons&#10;E) uncharged atom: the number of electrons = the number of protons

Accepted Answer

The atomic mass number is the sum of the number of protons and neutrons in an atom, not protons and electrons.

Question 6

The building blocks of ________ are ________ .&#10;A) polysaccharides; fatty acids&#10;B) DNA; nucleotides&#10;C) nucleic acids; amino acids&#10;D) polysaccharides; glycerol&#10;E) fats; monosaccharides

Accepted Answer

DNA is composed of nucleotides, which are the building blocks of nucleic acids. Polysaccharides are composed of monosaccharides, not fatty acids or glycerol. Fats are composed of fatty acids and glycerol, not monosaccharides. Amino acids are the building blocks of proteins, which are composed of polypeptide chains, not nucleic acids.

Question 7

Which of the following compounds will not dissolve in water?&#10;A) one consisting largely of non-polar covalent bonds&#10;B) one consisting largely of polar covalent bonds&#10;C) one consisting largely of ionic bonds&#10;D) one that readily forms hydrogen bonds&#10;E) one in which many of the atoms have partial charges

Accepted Answer

Compounds consisting largely of non-polar covalent bonds do not dissolve well in water because water is a polar solvent, and like dissolves like. Polar compounds, ionic compounds, and those that can form hydrogen bonds or have partial charges are generally soluble in water.

Question 8

The purines of nucleic acids are ________ and ________.&#10;A) thymine; guanine&#10;B) adenine; guanine&#10;C) adenine; cytosine&#10;D) thymine; cytosine&#10;E) cytosine; guanine

Accepted Answer

Purines are one of the two types of nitrogenous bases found in nucleic acids, the other being pyrimidines. Adenine and guanine are both purines, while thymine and cytosine are pyrimidines. Therefore, the correct answer is B.

Question 9

Why do proteins become less active as they lose their three-dimensional shape?

Accepted Answer

The answer of Why do proteins become less active as...

Question 10

Enzymes function by ________, which speeds up the rate of a chemical reaction.&#10;A) increasing the stability of the reactants&#10;B) multiplying the number of active sites on the reactants&#10;C) lowering the energy of activation&#10;D) increasing the energy of activation&#10;E) keeping the pH constant

Accepted Answer

Enzymes lower the activation energy required for a chemical reaction to occur, which allows the reaction to happen more quickly. It does not increase the stability of the reactants or multiply the number of active sites. Enzymes also do not increase the energy of activation or keep the pH constant.

Question 11

Describe the relationship between an atom's stability and its energy. How does this impact an atom's reactivity?

Accepted Answer

The answer of Describe the relationship between an atom's stability...

Question 12

What factors determine if a substance will or will not dissolve in water?

Accepted Answer

The answer of What factors determine if a substance will...

Question 13

An atom has 1 electron in an outer shell that holds a maximum of eight electrons. This atom:&#10;A) is most likely an inert gas.&#10;B) will most likely form polar covalent bonds.&#10;C) will most likely gain electrons to achieve stability.&#10;D) will most likely become a negatively charged ion to achieve stability.&#10;E) will most likely lose its outer electron to achieve stability.

Accepted Answer

The answer of An atom has 1 electron in an...

Deck 2: The Chemistry of Life