Deck 2: Molecular Interactions

Question 1

The most important polar molecule is ________ because it is practically a universal solvent.

A) water
B) bicarbonate
C) sodium chloride
D) magnesium sulfate
E) nucleic acid

Answer 1

A

Question 2

Glycosylated molecules are those formed with which group of organic compounds?

A) lipids
B) nucleic acids
C) lysosomes
D) cholesterol
E) DNA

Answer 2

A

Question 3

Which group of elements makes up more than 90% of the body's mass?

A) O, H, Na
B) C, Na, K
C) O, Ca, H
D) Ca, C, O
E) O, C, H

Answer 3

E

Question 4

Cells regulate their level of activity by regulating the amount of proteins present in the cell at any given time, so an up regulation of enzymes would be expected to

A) increase the cell's response that is produced by the reaction catalyzed by the enzyme.
B) decrease the level of productivity of chemical reactions that rely on them.
C) have no effect on the rate of reactions catalyzed by the enzymes.
D) decrease the rate of reactions catalyzed by the enzymes.
E) both decrease the level of productivity of chemical reactions that rely on them and decrease the rate of reactions catalyzed by the enzymes.

Question 5

The weak interactions between atoms that keep atoms near each other are called

A) hydrogen bonds.
B) van der Waals forces.
C) ionic bonds.
D) hydrogen bonds and van der Waals forces.
E) van der Waals forces and ionic bonds.

Question 6

All of these statements about carbohydrates are True EXCEPT one.Identify the exception.

A) Simple sugars include galactose, glucose, and ribose.
B) Cellulose is the most abundant polysaccharide on earth.
C) Glycogen is a storage polysaccharide made by animal cells.
D) Polysaccharides are important both for energy storage and to provide structure to cells.
E) Glycogen is important both for energy storage and to provide structure for cells.

Question 7

Chromium is

A) not an element in the periodic table.
B) a protein.
C) a dietary supplement with no natural role in the body.
D) an essential element involved in glucose metabolism.

Question 8

Which of the following is a way to recognize a carbohydrate by looking at its name only?

A) It ends in -ase.
B) It ends in -ose.
C) It begins with nucleo-.
D) It begins with proteo-.
E) It begins with lipo-.

Question 9

The chemical bonding behavior of an atom is directly determined by the

A) number of protons.
B) number of neutrons.
C) number and arrangement of electrons.
D) size of the atom.
E) mass of the atom.

Question 10

Atoms in a covalent molecule

A) share electrons in single pairs.
B) share electrons in double pairs.
C) share electrons in triple pairs.
D) share electrons singly, never in pairs.
E) can share electrons in single pairs, double pairs, or triple pairs.

Question 11

Essential amino acids that are used to build proteins

A) exist in twenty six different configurations.
B) are linked together by ionic chemical bonds in proteins.
C) can be used medically for both diagnosis and treatment of diseases.
D) are derived from the foods we eat and digest.
E) can only be made by cells within our bodies.

Question 12

A free radical is a

A) charged particle.
B) molecule with an extra electron.
C) molecule with an extra neutron.
D) molecule with an extra proton.
E) molecule with an unpaired electron.

Question 13

Stanley Miller set out to demonstrate an explanation for the origins of organic molecules using a combination of simple organic molecules, heat and periodic bursts of electricity through the mixture, ultimately producing which kind of molecules?

A) carbohydrates
B) amino acids
C) lipids
D) glycoproteins
E) nucleic acids

Question 14

A molecule referred to as highly soluble is

A) very likely to dissolve in water.
B) not very likely to dissolve in water.
C) called aqueous.
D) very likely to dissolve in water and is called aqueous.
E) not very likely to dissolve in water and is called aqueous.

Question 15

Which of the following are examples of cations?

A) SO₄²⁻
B) Ca²⁺
C) HPO₄²⁻
D) HCO₃⁻
E) Cl⁻

Question 16

Which of the following is NOT considered an essential element for a living organism?

A) carbon
B) hydrogen
C) mercury
D) oxygen
E) nitrogen

Question 17

A positively-charged ion is called a(n)

A) electron.
B) proton.
C) neutron.
D) cation.
E) anion.

Question 18

When an enzyme reaches its saturation point, the amount of

A) substrate for the enzyme to act upon is very high.
B) substrate for the enzyme to act upon is very low.
C) product produced continues to increase.
D) product produced by the enzyme decreases.
E) substrate for the enzyme to act upon is very low and the amount of product produced by the enzyme decreases.

Question 19

The largest carbohydrate molecules are called polysaccharides because they are composed of ________ molecules bonded together with one another.

A) amino acid
B) nucleotide
C) purine
D) pyrimidine
E) simple sugar

Question 20

The organic molecules known as phospholipids are key components of cell membranes and composed of which molecules?

A) amino acids
B) nucleotides
C) glycerol
D) fatty acids
E) both glycerol and fatty acids

Question 21

An ion has gained or lost

A) a proton(s).
B) a neutron(s).
C) an electron(s).
D) a carbon atom(s).
E) a double bond.

Question 22

Interactions between different globular or fibrous polypeptide chains result in which type of structure?

A) primary
B) secondary
C) tertiary
D) quaternary
E) pentagonal

Question 23

Polymers are a typical formation of ________ molecules.

A) organic
B) inorganic
C) either organic or inorganic

Question 24

Which of the following is a common feature of soluble proteins?

A) structural support
B) noncovalent interaction
C) receptor binding
D) chemical modulation
E) All of the answers are correct.

Question 25

A nucleotide consists of a

A) five-carbon sugar and phosphate group.
B) five-carbon sugar and a nitrogenous base.
C) phosphate group and a nitrogenous base.
D) five-carbon sugar, a nitrogenous base, and a phosphate group.
E) five-carbon sugar and an amino acid.

Question 26

Each amino acid differs from others in the

A) number of central carbon atoms.
B) size of the amino group.
C) number of carboxyl groups.
D) chemical structure of the R group.
E) number of peptide bonds in the molecule.

Question 27

Protein specificity is the

A) activation of a specific protein that is needed to perform a particular function.
B) degree to which a protein is attracted to a ligand.
C) ability of a protein to bind a certain ligand or a group of related ligands.
D) degree to which a protein-ligand complex initiates a response.
E) degree to which a protein is attracted to a ligand and the ability of a protein to bind a certain ligand or a group of related ligands.

Question 28

Nucleic acids are polymers of units called

A) amino acids.
B) fatty acids.
C) bases.
D) ribose.
E) nucleotides.

Question 29

A component of an important buffer in the human body is

A) NaCl.
B) H⁺.
C) HCl.
D) HCO₃⁻.
E) H₂O.

Question 30

Which bases below are purines?
1)adenine
2)cytosine
3)guanine
4)thymine
5)uracil

A) 1 and 2
B) 2 and 3
C) 1, 3, and 5
D) 1 and 3
E) 2, 4, and 5

Question 31

Isotopes of the same element differ by having different numbers of

A) protons.
B) neutrons.
C) electrons.
D) carbon atoms.
E) double bonds.

Question 32

Cholesterol is a

A) precursor to steroid hormones.
B) structural component of cell membranes.
C) dangerous fat that is absent from a healthy body.
D) precursor to steroid hormones and a structural component of cell membranes.
E) precursor to steroid hormones, a structural component of cell membranes, and a dangerous fat that is absent from a healthy body.

Question 33

Which of the following substances is most alkaline?

A) lemon juice, pH = 2
B) urine, pH = 6
C) tomato juice, pH = 4
D) white wine, pH = 3
E) stomach secretions, pH = 1

Question 34

The concentration of a solution expresses the amount of

A) solvent per volume of solute.
B) solute per volume of solvent.
C) solvent per volume of solution.
D) solute per volume of solution.
E) None of the answers are correct.

Question 35

The most important energy-transferring compound in cells is a nucleotide known as

A) glucose.
B) fructose.
C) protein.
D) adenosine triphosphate.
E) deoxyribonucleic acid.

Question 36

The identity of an element can be determined by the number of

A) protons.
B) neutrons.
C) electrons.
D) carbon atoms.
E) double bonds.

Question 37

According to the rules of complementary base pairing, a nucleotide containing the base cytosine would only pair with a nucleotide containing the base

A) thymine.
B) adenine.
C) uracil.
D) cytosine.
E) guanine.

Question 38

If a substance has a pH that is less than 7, it is considered

A) neutral.
B) acidic.
C) alkaline.
D) a buffer.
E) a salt.

Question 39

The alpha-helix and pleated sheet are examples of the ________ structure of a protein.

A) primary
B) secondary
C) tertiary
D) quaternary
E) pentanary

Question 40

In regard to lipids, the term unsaturated refers to

A) the lack of double bonds between adjacent carbon atoms in a fatty acid.
B) the presence of double bonds between adjacent carbon atoms in a fatty acid.
C) the ring structure of steroids.
D) glycerol, which acts as an anchor for joined fatty acids.
E) fats, such as butter and lard, which come from animal sources.

Question 41

All organic molecules contain which of the following?

A) calcium
B) carbon
C) adenosine
D) oxygen
E) lipids

Question 42

Which of the following statements best describes the relationship between pH and hydrogen ions?

A) pH and hydrogen ions are equivalent.
B) pH and hydrogen ions are directly proportional.
C) pH and hydrogen ions are inversely proportional.
D) pH is always 100 times more than the number of hydrogen ions.
E) pH and hydrogen ions are independent and unrelated.

Question 43

This particle has a charge of +1 and a mass of 1.

A) proton
B) neutron
C) electron
D) molecular oxygen
E) sodium chloride

Question 44

These result when the carbon atoms in phospholipids share a pair of electrons.

A) a Van der Waals attraction
B) an ionic bond
C) a hydrogen bond
D) a covalent bond
E) a potassium bond

Question 45

This particle has a neutral charge and a mass of 1.

A) proton
B) neutron
C) electron
D) hydrogen
E) magnesium

Question 46

A change in pH value of one unit indicates a

A) 1-fold change in [H⁺].
B) change of 10⁻¹ in pH.
C) change of 10⁻² in pH.
D) 10 fold change in [H⁺].
E) Cannot be determined.

Question 47

Which of the following biological molecules exhibit the characteristics of saturation, specificity and competition?

A) carbohydrates
B) lipids
C) receptor proteins
D) nucleotides
E) lipids and proteins

Question 48

Molecules that contain the element carbon are known as

A) organic molecules.
B) essential elements.
C) nucleic acids.
D) protons.
E) vitamins.

Question 49

Van der Waals forces are weak attractive forces between the nucleus of one atom and the electrons of another atom close by.

Question 50

Molecular function and distinctive shapes of large complex biomolecules result from the interactions of which of the following?

A) van der Waals forces
B) ionic bonds
C) hydrogen bonds
D) covalent bond angles
E) All of the choices can contribute.

Question 51

Which of the following combination of elements make up 90% of the body's mass?

A) oxygen, carbon, and nucleic acids
B) hydrogen, nitrogen, and oxygen
C) oxygen, carbon, and hydrogen
D) carbon dioxide, oxygen, and sodium
E) sodium, potassium, and calcium

Question 52

These are weak attractive forces that are responsible for the surface tension of water.

A) a Van der Waals attraction
B) an ionic bond
C) a hydrogen bond
D) a covalent bond
E) a potassium bond

Question 53

HCl (hydrochloric acid)is considered an acid because

A) in solution it donates its H⁺.
B) in solution it decreases the concentration of free H⁺.
C) in solution it increases the pH.
D) it is similar to ammonia.
E) it is able to form hydroxide ions.

Question 54

A blood pH of less than 7.00 and greater than 7.70 is incompatible with life.

Question 55

Which of the following formulas describes the relationship between pH and hydrogen ions?

A) pH = log [H⁺]
B) pH = -log [H⁺]
C) [H⁺] = -log pH
D) [H⁺] = log pH
E) pH= [H⁺] + [OH⁻]

Question 56

Nucleotides participate in which of the following functions?

A) They combine with oxygen to produce energy.
B) They are the building blocks of proteins like cell receptors.
C) They form structural elements in the cell membrane.
D) They transfer energy and are part of genetic material.
E) They store glucose as fat.

Question 57

Which of the following results when an atom has such a strong attraction for electrons that it pulls one or more electrons completely away from another atom?

A) a Van der Waals attraction
B) an ionic bond
C) a hydrogen bond
D) a covalent bond
E) a very stable bond

Question 58

Which of the following biological molecules does glycogen belong to?

A) carbohydrates
B) lipids
C) proteins
D) nucleotides
E) lipids and proteins

Question 59

This particle has a charge of -1 and a negligible mass.

A) proton
B) neutron
C) electron
D) hydrogen
E) magnesium

Question 60

To which of the following groups of biomolecules do triglycerides and steroids belong?

A) carbohydrates
B) lipids
C) proteins
D) nucleotides
E) lipids and proteins

Question 61

Ions with a positive charge are called

A) anions.
B) electrons.
C) cations.
D) neurons.
E) tissues.

Question 62

Which of the following would be disrupted by changes in free hydrogen ions in solution, thus disrupting the molecule's shape and function?

A) disulfide bonds
B) hydrogen bonds
C) sodium bonds
D) covalent bonds
E) double bonds

Question 63

Hemoglobin molecules are made from four globular protein subunits.The three-dimensional shape of these globular subunits would be an example of which of the following levels of protein structure?

A) primary
B) secondary
C) teritiary
D) quaternary
E) alpha helix

Question 64

A(n)________ is a substance that consists entirely of atoms with the same atomic number.

A) atom
B) molecule
C) element
D) nucleus
E) tissue

Question 65

Potassium channels are usually composed of several subunits.This is an example of which level of protein structure?

A) primary
B) secondary
C) teritiary
D) quaternary
E) alpha helix

Question 66

The center of an atom is called the

A) proton.
B) molecule.
C) element.
D) nucleus.
E) electron.

Question 67

Electrons travel around the center of the atom at high speed forming a(n)

A) atom.
B) molecule.
C) element.
D) nucleus.
E) shell.

Question 68

During intense exercise our muscles produce lactate and hydrogen ions.Which of the following molecules would be affected by the accumulation of hydrogen ions?

A) cholesterol in the plasma membrane
B) glucose molecules in the adipose tissue
C) DNA in the nucleus
D) the proteins actin and myosin
E) phospholipids in the membrane

Question 69

The protein keratin which is found in hair and nails and affords nails their rigid structure would be categorized as which of the following protein shapes?

A) fibrous
B) globular
C) acidic
D) hexavalent
E) triangular

Question 70

Which of the following levels of protein structure occurs from spontaneous folding that results from covalent bonds and noncovalent interactions?

A) primary
B) secondary
C) teritiary
D) quaternary
E) triangular

Question 71

If a reaction which is stopped by substance X can recover when a lot more of the native activator is supplied, substance X would be considered which of the following?

A) covalent modulator
B) competitive inhibitor
C) allosteric modulator
D) irreversible antagonist
E) a phosphotase

Question 72

Which of the following types of bonds between adjacent amino acids plays an important role in the shape of globular proteins?

A) collagen bonds
B) disulfide bonds
C) sodium bonds
D) metallic bond
E) secondary bonds

Question 73

When glucose enters a cell it is phosphorylated in order to maintain a low glucose concentration in the cell.The enzyme that phosphorylates glucose would be what kind of modulator?

A) covalent modulator
B) competitive inhibitor
C) allosteric modulator
D) reversible antagonist
E) irreversible agonist

Question 74

Which of the following best describes an irreversible antagonist?

A) involved in activation via phosphorylation
B) cannot be displaced by competition
C) binds to proteins away from the active site
D) reversible antagonist
E) allosteric enhancer

Question 75

Beta strands are an example of a spatial arrangement of amino acids.

Question 76

An element's ability to bind to and with other elements is determined by which of the following?

A) the arrangement of electrons in the outer shell of an atom
B) its amino acid composition
C) its state of glycosylation
D) the number of enzymes required
E) the amount of folding in its subunits

Question 77

Which of the following would be considered an allosteric modulator?

A) A substance involved in activation via phosphorylation.
B) A substance that can be displaced by competition at the active site.
C) A substance that binds to proteins away from the active site.
D) A substance that has no effect on the affinity of the ligand.
E) A substance that binds irreversibly.

Question 78

When two or more atoms are chemically linked, the smallest unit of the resulting material is referred to as a(n)

A) atom.
B) molecule.
C) element.
D) nucleus.
E) tissue.

Question 79

The smallest unit of an element is a(n)

A) atom.
B) molecule.
C) element.
D) nucleus.
E) tissue.

Question 80

The sequence and number of amino acids in the chain is an example of which of the following levels of protein structure?

A) primary
B) secondary
C) teritiary
D) quaternary
E) alpha helix