Chapter 2 HW

Isotopes are atoms of the same element that differ in - the number of protons and electrons found in the atom. - the number of neutrons found in the nucleus. - the number of protons and neutrons found in the nucleus. - the number of electrons orbiting the nucleus. - the number of protons found in the nucleus.

the number of neutrons found in the nucleus.

An atom is best described as - defined by its atomic mass. - the smallest unit of an element. - always containing an equal number of protons and neutrons. - having a nucleus containing protons and electrons. - defined by its number of electrons.

the smallest unit of an element

In a dehydration synthesis reaction, macromolecules are built when ________ is removed to form a covalent bond. - water - oxygen - an amino acid - carbon dioxide - an electron

water

Which of the following is (are) organic? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. - CO2 - HCl - CH4 - C6H12O6

- CH4 - C6H12O6

Using the Periodic Table of Elements, select all of the true statements about carbon. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. - One carbon atom contains 6 protons and 6 neutrons - A carbon atom has 12 electrons - Carbon's atomic number is 6 - Carbon's atomic mass is 16

- One carbon atom contains 6 protons and 6 neutrons - One carbon atom contains 6 protons and 6 neutrons

Choose the false statement(s) about acids and bases. To be marked correct, you'll need to select all false statements, as there may be more than one correct answer.\ - Bases release OH- ions in an aqueous solution. - Pure water has more H+ ions than OH- ions. - Acids contribute H+ ions to an aqueous solution. - If an acid is added to an acidic solution, the pH will increase.

- Pure water has more H+ ions than OH- ions. - If an acid is added to an acidic solution, the pH will increase.

Referring to the following reaction, identify the product of the reaction. 3H2 (g) + N2 (g) → 2NH3 (g) - 3H2 (g) and N2 (g) - N2 (g) - 2NH3 (g) - 3H2 (g)

2NH3 (g)

Which of the following best describes the tertiary structure of proteins? - 3D globular structures stabilized by covalent disulfide bridges - Two or more polypeptide chains interacting to form a higher-order structure - Linear protein folded into alpha helices and beta- pleated sheets - Amino acids linked by peptide bonds

3D globular structures stabilized by covalent disulfide bridges

Which of the biomolecules is incorrectly matched with its building block? - Lipid: Fatty acid - Carbohydrate: Polysaccharide - Nucleic acid: Nucleotide - Lipid: Glycerol - Protein: Amino acid

Carbohydrate: Polysaccharide

____________ are organic or inorganic substances that increase the rate of a reaction but are not used up in the reaction. - Reactants - Products - Catalysts - Vitamins

Catalysts

__________ are small proteins that help fold larger proteins. - Polypeptides - Chaperones - Amino acids - Proteases

Chaperones

___________ are formed when ionic compounds dissolve in solution and have a role in regulating blood volume. - Electrons - Protons - Electrolytes - Buffers

Electrolytes

____________ do not bind atoms into molecules. Instead, they are non-covalent electrostatic attractions between two or more molecules or within a single large molecule. - Covalent bonds - Hydrogen bonds - Van der Waals interactions - Ionic bonds

Hydrogen bonds

_____________ are atoms with the same number of protons but a different number of neutrons. - Isotopes - Molecules - Compounds - Ions

Isotopes

Which type of bond links amino acids together to form a protein's primary structure? - Hydrogen bonds - Glycosidic bonds - Peptide bonds - Phosphodiester bonds

Peptide bonds

Which particle is described incorrectly? - Proton: Found in shells orbiting the nucleus - Electron: Negatively charged and negligible mass - Electron: Found in shells orbiting the nucleus - Proton: Positively charged and 1 atomic mass unit - Neutron: Found in the nucleus and 1 atomic mass unit

Proton: Found in shells orbiting the nucleus

Which of the following is incorrectly matched? - Base: Release hydroxide ions (OH-) in an aqueous solution - Water: Is the solvent in aqueous solutions - pH: Measure of the acidity or basicity of a solution - Acid: Release hydrogen ions (H+) in an aqueous solution - Salt: Formed by the combination of hydrogen ions (H+) and hydroxide ions (OH-)

Salt: Formed by the combination of hydrogen ions (H+) and hydroxide ions (OH-)

Which of the following lipids tends to be liquid at room temperature? - Fats - Saturated lipids - Waxes - Unsaturated lipids

Unsaturated lipids

___________ are usually found in an atom's outermost shell and tend to participate in chemical reactions. - Shared electrons - Valence electrons - Reactive protons - Neutral neutrons

Valence electrons

Which statement is true about valence electrons? - Interactions between valence electrons in reacting atoms determine what kind of chemical bond is formed. - Valence electrons participate in chemical reactions. - Valence electrons participate in chemical reactions, and interactions between valence electrons in reacting atoms determine what kind of chemical bond is formed. - Valence electrons are found in the innermost shell and participate in chemical reactions. - Valence electrons are found in the innermost shell.

Valence electrons participate in chemical reactions, and interactions between valence electrons in reacting atoms determine what kind of chemical bond is formed.

Which type of lipid is incorrectly matched to its description? - Mono-, di-, or triglyceride: One, two, or three fatty acids linked to a glycerol molecule - Wax: Refers to any lipid which is solid at room temperature - Glycolipid: A lipid linked to a carbohydrate - Steroid: Made of four fused hydrocarbon rings - Phospholipid: An amphipathic lipid found in the plasma membrane of cells

Wax: Refers to any lipid which is solid at room temperature

An anion is formed when - an atom has an equal number of positively-charged protons and negatively-charged electrons. - an atom gains one or more negatively-charged electrons. - an atom loses one or more negatively-charged electrons. - an atom loses one or more positively-charged protons. - an atom gains one or more positively-charged protons.

an atom gains one or more negatively-charged electrons.

Which of the following is not one of the four main groups of biomolecules? - carbohydrates - electrolytes - nucleic acids - proteins - lipids

electrolytes

Van der Waals interactions - exhibit a force of repulsion that serves to destabilize molecules. - are responsible for the repulsion between hydrophilic and hydrophobic compounds. - are another name for hydrogen bonds. - occur when temporary dipoles within molecules form that are not the result of hydrogen bond to O, N, or F atoms. - are stronger than either hydrogen bonds or ionic bonds.

occur when temporary dipoles within molecules form that are not the result of hydrogen bond to O, N, or F atoms.

Compared to a solution with a pH value of 4, a solution with a pH value of 2 has ________ H+ ions. - one hundred times as many - half as many - one hundred times fewer - the same number of - twice as many

one hundred times as many