Chemistry Chapter

____51) 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

A

____53) Beta strands are an example of a spatial arrangement of amino acids. A) True B) False

A

____55) 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

A

____60) 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

A

____65) 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

A

____71) The purines found in DNA are ________ and ________. A) adenine, guanine B) ribose, thymine C) deoxyribose, guanine D) guanine, cytosine E) uracil, adenine

A

____74) List the following in order of increasing mass: atom, molecule, proton, neutron, electron. A) electron < proton < neutron < atom < molecule B) neutron < proton < electron < atom < molecule C) electron < proton < atom < neutron < molecule D) proton < neutron < electron < atom < molecule E) atom < electron < proton < neutron < molecule

A

____75) Which of the following elements combine to form nonpolar covalent bonds? A) carbon and hydrogen B) nitrogen and hydrogen C) sodium and chlorine D) hydrogen and oxygen E) carbon and chlorine

A

____78) Lipids are hydrophobic, and do not usually dissolve in water. Because blood is water-based, the lipid cholesterol is combined with ________ so that it can be transported by blood. A) hydrophilic molecules B) hydrophobic molecules C) nothing; cholesterol is not transported in blood D) cations E) anions

A

____80) Chemical reactions that occur in the human body proceed at a faster rate due to special catalytic molecules called A) enzymes. B) cytozymes. C) proteins. D) antibodies. E) antagonists.

A

The fuel molecule that cells use to run their activities is Sucrose Protein Vitamins Glucose

Glucose

____58) 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

D

____64) The center of an atom is called the A) proton. B) molecule. C) element. D) nucleus.

D

____68) A(n) ________ is any molecule or ion that binds to another molecule. A) phospholipid B) enzyme C) vitamin D) ligand E) cofactor

D

____73) The reaction rates of many chemical reactions that occur in the body are controlled by special protein molecules called A) neurotransmitters. B) purines. C) nucleic acids. D) enzymes. E) intermediates.

D

____69) The molecule DNA contains the five-carbon sugar A) lactose. B) ribose. C) deoxyribose. D) glucose. E) uracil.

C

A change in pH value of +1 indicates: 1-fold change in [H+] Change of 10-1 in [H+] 10-fold change in [H+] 100-fold change in [H+]

10-fold change in [H+]

____25) 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

5

____36) A blood pH of less than 7.00 and greater than 7.70 is incompatible with life. A) True B) False

a

Of what is this the basic structure? NH2—RCH-COOH? Amino acid Protein Carbohydrate Fatty acid

Amino Acid

____3) 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-.

B

____49) 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

B

____57) 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

B

____61) 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 phosphatase

B

____63) 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.

B

____67) Molecules that readily dissolve in water are called A) hydrophobic. B) hydrophilic. C) isotonic. D) non-polar. E) lipids.

B

____70) The molecule RNA contains the five-carbon sugar A) lactose. B) ribose. C) deoxyribose. D) glucose. E) uracil.

B

____72) The pyrimidines found in DNA are ________ and ________. A) adenine, guanine B) cytosine, thymine C) deoxyribose, guanine D) guanine, cytosine E) uracil, adenine

B

____76) In a 5% NaCl solution, A) there are 5 grams of sodium chloride for every 100 mL of water. B) there are 5 grams of sodium chloride for every 100 mL of total solution. C) the solute is water. D) there are 5 grams of sodium chloride for every 100 mL of water and there are 5 grams of sodium chloride for every 100 mL of total solution. E) there are 5 grams of sodium chloride for every 100 mL of total solution and the solute is water.

B

____79) In the equation CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3-, which of these is an acid? A) HCO3- B) H2CO3 C) H2O D) CO2 E) H+

B

____4) Which of the following is NOT considered an essential element for a living organism? A) carbon B) hydrogen C) mercury D) oxygen E) nitrogen

C

____48) 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

C

____52) 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

C

____54) 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

C

____59) 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

C

____62) 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.

C

____66) Ions with a positive charge are called A) anions. B) electrons. C) cations. D) neurons. E) tissues.

C

____77) The term polar is used to describe molecules because A) polar covalent molecules are found in colder climates. B) polar covalent molecules were first discovered in polar bears. C) there are at least two distinct ends of the molecule regarding electron position and the resulting charge. D) there are at least two distinct ends of the molecule regarding hydrogen placement. E) such molecules are always linear in shape.

C

Which of the following is likely to lose two electrons? Sodium Potassium Calcium Oxygen

Calcium

All organic molecules contain Calcium Carbon Oxygen Lipids

Carbon

Which of the following is most likely gain an electron? Sodium Hydrogen Potassium Chloride

Chloride

These results when carbon atoms in phospholipids share electrons Ionic bonds Hydrogen bonds Covalent bonds Potassium bonds

Covalent

____50) 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

D

____1) 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

E

____2) 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

E

____56) 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

E

This particle has a charge of -1 and negligible mass. Proton Neutron Electron Protons and neutrons

Electron

The reaction rates of many chemical reactions in the body are controlled by Neurotransmitters Nucleic acids Enzymes Intermediates

Enzymes

Molecules that do not dissolve well in water are called Hydrophobic Hydrophilic Isotonic Polar

Hydrophobic

Hydrochloric acid is considered an acid because In solution it donates H+ ions In solution it decreases H+ ions In solution is increases the pH It is able to form hydroxide ions

In solution it donates H+ ions**

Which of the following compounds is held together by ionic bonds? NaCl H2O O2 CH4

NaCl

Which of the following is a noble gas? Hydrogen Oxygen Neon Carbon

Neon

Isotopes of the same atom differ in the number of ___. Protons Neutrons Electrons Both protons and neutrons

Neutrons

What kind of molecule is carbon tetrachloride (CCl4)? Non-polar Ionic Polar covalent None of these answers is correct

Non-polar

The center of an atom is called a Proton Element Nucleus Electron

Nucleus

An elements' ability to bind with others is determined by Number and arrangement of electrons in the outer most shell Amino acid composition Number of enymzes used Amount of folding in subunits

Number and arrangement of electrons in the outer most shell

What kind of bonds are found in CCl4? Ionic Non-polar covalent Polar covalent None of these answer is correct

Polar Covalent

Which of the following is likely to lose an electron? Helium Fluorine Potassium Iodide

Potassium

The sequence and number of amino acids in a chain is what level of protein structure? Primary Secondary Tertiary Quartenary

Primary

The identity of an element can be determined by the number of ___. Protons Neutrons Electrons Double-bonds

Pro

This particle has a charge of +1 and a mass of 1 amu Neutron Proton Electron Both protons and neutrons

Pro

Hemoglobin consists of two alpha and two beta chains. What level of organization is this? Primary Secondary Tertiary Quartenary

Quartenary

____38) 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.

a

Most of the lipids found in the human body are in the form of Steroids Phospholipids Triglycerides Monoglycerides

Triglycerides

____46) Which of the following biological molecules does glycogen belong to? A) carbohydrates B) lipids C) proteins D) nucleotides E) lipids and proteins

a

____9) 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

a

____11) 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.

a

____26) Polymers are a typical formation of ________ molecules. A) organic B) inorganic C) either organic or inorganic

a

____16) 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.

b

____18) The alpha-helix and pleated sheet are examples of the ________ structure of a protein. A) primary B) secondary C) tertiary D) quaternary E) pentanary

b

____29) 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

b

____30) 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.

b

____32) 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.

b

____34) Isotopes of the same element differ by having different numbers of A) protons. B) neutrons. C) electrons. D) carbon atoms. E) double bonds.

b

____40) 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-]

b

____41) All organic molecules contain which of the following? A) calcium B) carbon C) adenosine D) oxygen E) lipids

b

____43) 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

b

____7) Which of the following are examples of cations? A) SO42- B) Ca2+ C) HPO42- D) HCO3- E) Cl-

b

____12) 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.

c

____31) 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.

c

____33) 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.

c

____37) 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.

c

____42) 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

c

____44) 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

c

____10) 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.

d

____14) 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.

d

____17) 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.

d

____19) Interactions between different globular or fibrous polypeptide chains result in which type of structure? A) primary B) secondary C) tertiary D) quaternary E) pentagonal

d

____20) 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.

d

____22) 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.

d

____24) 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.

d

____27) 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.

d

____28) A component of an important buffer in the human body is A) NaCl. B) H+. C) HCl. D) HCO3-. E) H2O.

d

____35) 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.

d

____45) 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

d

____47) 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.

d

____6) 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.

d

____8) A positively-charged ion is called a(n) A) electron. B) proton. C) neutron. D) cation. E) anion.

d

____13) 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.

e

____15) 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.

e

____21) Nucleic acids are polymers of units called A) amino acids. B) fatty acids. C) bases. D) ribose. E) nucleotides.

e

____23) 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.

e

____39) 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.

e

____5) 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

e

Which of the following formulas describe the relationship between pH and [H+]? pH = log {H+] pH = - log[H+] [H+] = -log pH pH = [H+] + [OH-]

pH = - log[H+]**