Deck 2: Chemistery of Life

Question 1

Carbon dating is a common method employed in dating certain kinds of fossils. It is based on the radioactive decay of an isotope of carbon C¹⁴). Referring to the atomic number of carbon attained from the periodic table, how many neutrons does C¹⁴ have?

A) 2
B) 4
C) 8
D) 12
E) 14

Answer 1

C.

Question 2

Which of the following elements will have more than two electrons and have a full outer orbital?

A) He
B) Ne
C) C
D) N
E) O

Answer 2

B.

Question 3

Ca₃PO₄)₂ represents an)

A) element.
B) mixture.
C) compound.
D) isotope.
E) atom.

Answer 3

C.

Question 4

The smallest unit of an element that still retains the chemical and physical properties of that element is called an)

A) isotope.
B) nucleus.
C) atom.
D) molecular bond.
E) neutrino.

Question 5

Radiation can have both positive and negative impact on humans.

Question 6

How many elements occur naturally?

A) 112
B) 92
C) 64
D) 32
E) 6

Question 7

Be has an atomic number of 4 and an atomic mass of 9. How many protons does it have?

A) 4
B) 5
C) 9
D) 13
E) 7

Question 8

The atomic number of an atom is determined by the number of

A) protons.
B) neutrons.
C) electrons.
D) protons and neutrons.
E) protons and electrons.

Question 9

Hydrogen bonds

A) result from the loss of neutrons by an atom.
B) result in the formation of salts.
C) involve the loss and gain of electrons.
D) involve the sharing of electrons.
E) are relatively weak and can be broken rather easily.

Question 10

Two or more atoms joined together through the sharing of electrons are called an)

A) atomic unit.
B) molecule.
C) compound.
D) isotope.
E) ion.

Question 11

Atoms that share electrons have what type of bonds?

A) covalent
B) neutral
C) hydrogen
D) colloidal
E) ionic

Question 12

CaCl₂ is a salt that forms as the result of what type of bond?

A) covalent
B) hydrogen
C) polar
D) nonpolar
E) ionic

Question 13

In an atom, the number of protons always equals the number of

A) electrons.
B) neutrons.
C) neutrons and protons.
D) quarks.
E) neutrinos.

Question 14

Isotopes of an element differ due to the number of

A) protons.
B) neutrons.
C) electrons.
D) both protons and electrons.
E) neutrinos.

Question 15

Why is He positioned above Ne in the periodic table?

A) They both have the same atomic mass.
B) They both have the same number of electrons in their outermost orbital.
C) They both have a full outermost orbital.
D) They both have the same atomic number.
E) They both have the same number of protons in their nuclei.

Question 16

What substance is used in medicine to produce various images of organs and tissues?

A) a mixture
B) a tracer
C) an emulsion
D) a colloid
E) a sensor

Question 17

Water makes up 60-70% of total body weight.

Question 18

What is the symbol for sodium?

A) Na
B) S
C) So
D) N
E) Dm

Question 19

Which type of bond is responsible for holding two water molecules together, creating the properties of water?

A) hydrogen
B) covalent
C) ionic
D) polar
E) double covalent

Question 20

An element cannot be broken down by chemical means.

Question 21

Which polysacccharide is stored as an energy source in the body of animals?

A) glycogen
B) glucose
C) cellulose
D) starch
E) chitin

Question 22

A potato stores a reserve of energy in its underground tuber in the form of

A) glycogen.
B) fat.
C) protein.
D) vitamins.
E) starch.

Question 23

A solution with a pH of 7 has 10 times as many H⁺ as a pH of 6.

Question 24

A solution containing 0.00001 moles of H⁺ has a pH of

A) 3.
B) 5.
C) 7.
D) 9.
E) 11.

Question 25

In biology, calling something organic means that it was grown without the use of any type of herbicide.

Question 26

NaCl is not an organic molecule.

Question 27

The presence of a buffer in our blood helps maintain homeostasis.

Question 28

After lunch, our digestive system will use the process of hydrolysis to break the food down into smaller subunits.

Question 29

Which of the following is not a monosaccharide?

A) glucose
B) fructose
C) galactose
D) maltose
E) None of these are monosaccharides.

Question 30

Joining small molecules monomers) together to form longer chains polymers) requires a process called

A) a hydrolysis reaction.
B) a dehydration reaction.
C) monomerization.
D) emulsification.
E) disassembly.

Question 31

In an acidic solution, the number of H⁺ is

A) less than the number of OH^-.
B) greater than the number of OH^-.
C) equal to the number of OH^-.
D) 3 times less than the number of OH^-.
E) 10 times less than the number of OH^-.

Question 32

What passes through the digestive tract as fiber or roughage?

A) maltose
B) glucose
C) glycogen
D) starch
E) cellulose

Question 33

Sugars with three to seven carbon atoms are called

A) monosaccharides.
B) disaccharides.
C) trisaccharides.
D) polysaccharides.
E) steroids.

Question 34

A hydrolysis reaction involves the loss of water.

Question 35

William noticed water mysteriously climbing up a capillary tube. This is an example of which property of water?

A) Frozen water is less dense than liquid water.
B) The temperature of liquid water rises and falls slowly.
C) Water molecules are cohesive.
D) Water has a high heat of vaporization.
E) Water is a solvent.

Question 36

On a warm day in April, Tina jumped into the swimming pool. To her surprise the water was really cold. Which property of water did she discover?

A) Water molecules are cohesive.
B) The temperature of liquid water rises and falls slowly.
C) Water possesses hydrogen bonds.
D) Water is a polar molecule.
E) Frozen water is less dense than liquid water.

Question 37

Which grouping of elements is found in carbohydrates?

A) C - H - O
B) C - H - P
C) H - O - Cl
D) N - S - O
E) Ca - H - O

Question 38

Which of the following characteristics of water is most responsible for the sinking of the Titanic?

A) Water is liquid at room temperature.
B) Water has a high heat of vaporization.
C) The temperature of liquid water rises and falls slowly.
D) Frozen water is less dense than liquid water.
E) Water molecules are cohesive.

Question 39

The reason water is polar is because

A) in polar molecules atoms share electrons evenly.
B) the electrons spend more time circling the oxygen atom than the hydrogens.
C) hydrophilic molecules interact with water.
D) hydrophobic molecules do not interact with water.
E) there is a transfer of electrons from the hydrogen to the oxygen.

Question 40

Which of the following is not one of the four classes of organic molecules found in cells?

A) vitamins
B) lipids
C) proteins
D) carbohydrates
E) nucleic acids

Question 41

Fats are usually of animal origin, while oils are usually of plant origin.

Question 42

Which of the following is not a function of proteins?

A) quick energy
B) support
C) transport
D) enzymes
E) motion

Question 43

The main function of carbohydrates is for long-term energy storage.

Question 44

Which polysaccharide is branched the most?

A) cellulose
B) starch
C) glycogen
D) glucose
E) fructose

Question 45

Which of the following foods would be a good source of fiber?

A) peaches
B) whole-wheat bread
C) peanuts
D) bran cereal
E) All of these are good sources of fiber.

Question 46

Which polysaccharide is consumed as a source of fiber?

A) cellulose
B) glycogen
C) glucose
D) chitin
E) starch

Question 47

Our body is capable of converting starch into glycogen.

Question 48

A fatty acid that contains only single bonds between the carbon atoms is considered

A) saturated.
B) unsaturated.
C) trans unsaturated.
D) a cholestrol.
E) a steroid.

Question 49

Which level of protein structure is characterized by alpha and beta sheets in which hydrogen bonding holds the shape in place?

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

Question 50

Why does a protein not function after it has been denatured?

A) The normal bonding between the R groups has been disturbed and the protein loses its normal shape.
B) The normal bonding between the beta sheets has been disturbed and the protein loses its normal shape.
C) The normal bonding between the hydrogens in the alpha helix has been disturbed and the protein loses its normal shape.
D) The R groups form additional bonds causing the structure to become more compact.
E) The normal peptide bonds are ruptured and the individual amino acids are not held together any more.

Question 51

When two amino acids combine via a dehydration reaction,

A) a peptide bond is formed.
B) the R groups are lost.
C) water is added to begin the reaction.
D) the carboxyl group of each join together.
E) the amino group of each join together.

Question 52

Starch, cellulose, and glycogen are alike in that they

A) are all made of glucose.
B) contain the same number of side chains.
C) have the same types of bonds between the monomer units.
D) are all found in animals.
E) can all be digested by our bodies.

Question 53

How are fats, phospholipids, and steroids alike?

A) They are all solid at room temperature.
B) They each contain a polar phosphate group.
C) They each contain only one fatty acid.
D) They do not dissolve in water.
E) They all contain at least one carbon ring.

Question 54

The monomer unit of a protein is

A) fatty acids.
B) amino acids.
C) monosaccharides.
D) polysaccharides.
E) nucleic acids.

Question 55

The sex hormones belong to which category of lipids?

A) steroids
B) fats
C) oils
D) triglycerides
E) phospholipids

Question 56

A fat contains how many fatty acids?

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

Question 57

Fats and oils function better than other biological molecules as energy-storage molecules because of the carbon they contain.

Question 58

The membranes of cells are composed primarily of

A) phospholipids.
B) fats.
C) oils.
D) steroids.
E) triglycerides.

Question 59

An alpha helix or a beta sheet are examples of what level of protein structure?

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

Question 60

What makes each amino acid unique?

A) the central carbon
B) the R group
C) the amino group
D) the carboxyl group
E) the carbon ring

Question 61

ATP is called the energy currency of the body because it is a type of electricity.

Question 62

The function of RNA in the body is to store the genetic information in the nucleus.

Question 63

A species has 29% of its DNA composed of the nucleotide containing guanine G). What percent does the nitrogen base thymine T) equal?

A) 58%
B) 42%
C) 21%
D) 67%
E) 29%

Question 64

Which of the following nitrogenous bases is not found in DNA?

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

Question 65

List the properties of water.

Question 66

The sides of the DNA ladder backbone) are

A) alternating carbons and nitrogens.
B) the R groups.
C) the nitrogenous bases.
D) alternating nitrogens and phosphates.
E) sugars and phosphates.

Question 67

Which of the following is not present in a nucleotide?

A) phosphate
B) nitrogenous base
C) five-ring sugar
D) an R group
E) a pentose

Question 68

Describe the structure and function of the DNA molecule.

Question 69

The primary level of protein structure is composed of amino acids in a linear sequence joined by peptide bonds.

Question 70

When an ATP molecule is used to supply energy, which of the following occurs?

A) a phosphate bond is added
B) a phosphate bond is broken
C) oxygen is removed
D) oxygen is added
E) an adenine is added

Question 71

All amino acids are alike in that their R groups are polar.

Question 72

ATP carries energy in the form of high-energy

A) carbohydrate bonds.
B) peptide bonds.
C) lipid bonds.
D) phosphate bonds.
E) hydrogen bonds.

Question 73

List the functions of proteins.