Deck 2: Chemical Composition of the Body

Question 1

Select the atom that would most likely form an anion from the following.

A) Ca
B) K
C) F
D) Ca and K

Answer 1

C

Question 2

A molecule with an unpaired electron in the outermost shell is known as a/an ____ _____. These may contribute significantly to dementia, aging of cells, and even atherosclerosis.

Answer 2

free radical

Question 3

Molecules which share an atomic number but differ in number of neutrons are known as _____.

Answer 3

isotopes

Question 4

Select the molecule that is NOT a compound.

A) CaCl₂
B) H₂O
C) O₂
D) CH₄

Question 5

What is the atomic number of an atom with 15 electrons, 15 protons, and 16 neutrons?

A) 16
B) 15
C) 31
D) 46

Question 6

Chemical symbols are used to denote different ____; these are ordered in the periodic table based on the number of protons that they contain.

Question 7

How many atoms of oxygen are in a molecule of carbonic acid (H₂CO₃)?

A) 6
B) 1
C) 3
D) 2

Question 8

_____ is another name for an atomic mass number, and one widely used to describe protein mass.

Question 9

How many neutrons does ³⁷Cl have, given an atomic number of 17?

A) 18
B) 17
C) 20
D) 37

Question 10

An atom with 10 electrons would have

A) two shells, both full
B) two shells, first is full and second has ten openings
C) two shells, first is full and second has six openings
D) two shells, first is full and second has sixteen openings

Question 11

Which of the following is a true statement about radioactive isotopes?

A) all have rapid decay times
B) all decay by losing neutrons, but remain the same element
C) all are unstable, decaying to more stable forms
D) the half-life refers to half the time required for complete decay

Question 12

An atom that will likely form a cation

A) has only one or two electrons in its valence shell
B) has six or seven electrons in its valence shell
C) has a valence shell that is half full
D) has a valence shell that is completely full

Question 13

The lesser elements include

A) H
B) Ca
C) C
D) N

Question 14

The subatomic particles that are important in understanding most biological reactions include protons with positive charge, and ____ with no charge.

Question 15

The element ____ is the most plentiful anion in extracellular fluid.

Question 16

A sample is brought in for C-14 testing to determine its age. The scientist estimates that 1/8 of the C-14 has not yet decayed. Approximately how old is the sample?

A) 5,600 years
B) 112,000 years
C) 22,400 years
D) 16,800 years

Question 17

Free radicals are very reactive because they have an unpaired ____ that interacts with other molecules.

A) protons
B) electrons
C) neutrons
D) protons or electrons

Question 18

The ion ____ is the most plentiful cation in intracellular fluid.

Question 19

Ionization occurs when an atom gains or loses

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

Question 20

An astronaut weighs less on the moon because

A) he has less mass
B) he has less matter
C) the force of gravity is less
D) the distance from the earth is less

Question 21

Compounds which lack carbon molecules, and usually, complexity, are ____ compounds.

Question 22

In order for an atom to form a triple bond, it must

A) have at least three electrons in its valence shell
B) be missing at least three electrons from its valence shell
C) bind to an atom from a different element
D) have at least three electrons or be missing three electrons from its valence shell

Question 23

Organic compounds must at a minimum contain the element _____.

Question 24

Which of the following atoms could form a triple covalent bond?

A) C
B) Ca
C) O
D) H

Question 25

Concentration of a solution is expressed by _____ when the units refer to number of moles of solute per liter of solution.

Question 26

An ionic compound which breaks apart into positive and negative ions in solution is called a/an _____.

Question 27

In polar covalent bonds, the element which has partial negative charge has greater _____ than the other atoms.

Question 28

Sweating cools the body because

A) the water in the sweat is cooler than the body temperature
B) the salts in the sweat utilize the energy in body heat to dissociate
C) the water in sweat uses a large amount of body heat to evaporate
D) water has a low heat of vaporization, which means the water is cooler when it evaporates

Question 29

Many ions are dissolved in the plasma of the blood. In this case the ions are the

A) solvent
B) solution
C) solute
D) solvent and solution

Question 30

Water is an excellent solvent for substances

A) that are held together by ionic bonds
B) that are held together by non-polar covalent bonds
C) that are hydrophobic
D) that form bonds by sharing electrons equally

Question 31

You are given an unknown liquid that mixes well with oil. From this, you determine that

A) the liquid would also mix well with water
B) the liquid would be a good solvent for salts
C) the liquid is likely hydrophilic
D) the liquid is likely hydrophobic
E) the liquid is likely hydrophilic, meaning it will mix well with water and is a good solvent for salts

Question 32

When a chemical reaction is at _____ _____, the rate of forward and reverse reactions are equal.

Question 33

Short-term bonding between two molecules due to a temporary change in electron distribution is termed

A) ionic bonding
B) covalent bonding
C) van der Waals interaction
D) hydrogen bonding

Question 34

According to the law of mass action, if the concentration of CO₂ decreases in the reaction CO₂ + H₂O ← → H₂CO₃, then

A) the reaction rate in the forward direction will increase
B) the reaction rate in the reverse direction will increase
C) the equilibrium will be disrupted
D) the equilibrium will be disrupted and the reaction rate in the reverse direction will increase

Question 35

When colute particles are large enough to scatter light, the liquid is technically a/an _____; this differs from a suspension where particles may precipitate.

Question 36

The molecule ___ has a polar covalent bond.

A) O₂
B) CH₄
C) N₂
D) CO₂

Question 37

Covalent bonds where electron sharing is equal are more specifically termed _____ covalent bonds.

Question 38

Van der Waals interactions can be interrupted if

A) two molecules are too far apart
B) two molecules are too close
C) two molecules are already using hydrogen bonds
D) two molecules are too close or too far apart

Question 39

For the chemical reaction 2NH₃ → N₂ + __ H₂, how many H₂ molecules will be produced for every two NH₃ that react?

A) 2
B) 3
C) 1
D) It depends on how many N₂ are formed.

Question 40

Fill in the terms to make this sentence correct: When the ____ is dissolved into the ____, it forms a ____.

A) solution; solute; solvent
B) solute; solvent; solution
C) solvent; solution; solute
D) solute; solution; solvent

Question 41

A 100 mM solution of CaCl₂ has ____ mEq/L

A) 100
B) 200
C) 300
D) 400

Question 42

What is the correct arrangement of the phospholipid bilayer (two layers)?

A) tails together with polar heads facing out
B) heads together with non-polar tails facing out
C) polar heads of one layer next to the tails of the next layer
D) It depends on the temperature. (At higher temperatures, more tails move to the outside of the layers.)

Question 43

The reverse of dehydration synthesis is

A) dehydration lysis
B) dimerization
C) rehydration synthesis
D) hydrolysis

Question 44

Nutritionists are encouraging the public to consume less sugar, but there are many names for "sugar." Which of the following ingredients would not increase "sugar" levels in the blood.

A) dates
B) cellulose
C) maltose
D) lactose

Question 45

You are given a sample of a cloudy liquid and set it on the desk. A few minutes later, you notice a layer of something on the bottom and the liquid appears to be clearing. Based on your observations, you can say with certainty that this sample is a

A) solution
B) colloid
C) suspension
D) solution and suspension

Question 46

A polyunsaturated fatty-acid will

A) have no double bonds and a maximum number of hydrogens
B) have at least two double bonds and fewer than maximum number of hydrogens
C) all double bonds and very few hydrogens
D) be solid at room temperature

Question 47

Polymers are broken down to monomers by a type of reaction called ____; this requires the addition of water molecules.

Question 48

Cellulose is a polysaccharide, formed from _____ by plants.

Question 49

Buffers play a role in maintaining pH by

A) absorbing excess H⁺
B) releasing additional H⁺
C) destroying excess H⁺
D) absorbing or releasing H⁺

Question 50

Sucrose is an example of

A) a carbohydrate
B) a disaccharide
C) an organic molecule
D) a disaccharide, carbohydrate, and organic molecule

Question 51

When water levels in the body decrease below normal, one would have

A) more difficulty maintaining body temperature
B) lower heat of vaporization
C) more lubrication at joints
D) a higher heat capacity

Question 52

When two biological monomers join together, it is termed dehydration synthesis because

A) it must occur in a dry environment
B) a water molecule is released from each monomer
C) a water molecule is produced by the reaction
D) other molecules in the area are dehydrated by the reaction

Question 53

The term _____ applies to phospholipids, and denotes molecules which have both polar and nonpolar regions.

Question 54

A sample of body fluid has a pH of 7.0. You can determine from this that

A) the fluid is in a state of acidosis
B) the fluid is in a state of alkalosis
C) the fluid is the appropriate pH because all body fluids are neutral
D) the fluid may be appropriate or acidic compared to normal values, depending upon what type of fluid it is (blood, urine, etc)

Question 55

____ ____ is the reaction that joins two monomers.

Question 56

What properties of carbon make it such a good atom to help form organic molecules?

A) it forms covalent bonds
B) it can bind with many other elements
C) it can form a variety of structures (straight, branched…)
D) it can form covalent bonds with a large variety of elements to form a wide range of structures

Question 57

Large molecules formed by covalent bonding of many identical or similar building-blocks are called ____.

Question 58

A 20% glucose solution can be made by adding

A) 20 moles of glucose to enough water to make 1 L
B) 20 moles of glucose to enough water to make 100 ml
C) 20 grams of glucose to enough water to make 1 L
D) 20 grams of glucose to enough water to make 100 ml

Question 59

What is the benefit of having glycogen stored in skeletal muscle?

A) It is linked to lots of water, so it prevents dehydration.
B) Glycogen can easily be broken into glucose molecules, so a source of energy is very close.
C) The water stored in glycogen makes muscle cells appear larger, and therefore stronger.
D) The branching of glycogen helps link muscle fibers to each other.

Question 60

These two functional groups are always found on the monomers of a protein.

A) carboxyl and amino
B) hydroxyl and carbonyl
C) sulfhydryl and ester
D) phosphate and sulfhydryl

Question 61

A chain of twenty amino acids is termed a

A) dipeptide
B) tripeptide
C) peptide
D) polypeptide

Question 62

A patient's body is not effectively fighting off a bacterial infection. The type of protein that is most likely malfunctioning is

A) structural
B) regulatory
C) immunological
D) transport

Question 63

A single type of ligand may fail to bind to a protein if complete ____ has been reached.

A) specificity
B) affinity
C) saturation
D) competition

Question 64

Cysteine is a critical amino acid component of many proteins because it is capable of forming very strong ____ bridges, which provides very strong force to shape tertiary structure.

Question 65

Lipids have many functions in the body, but NOT

A) aiding in inflammatory reactions
B) regulating sexual functions
C) storing energy
D) forming nucleic acids

Question 66

Alpha helix and beta sheet motifs in proteins are the level of ____ structure.

Question 67

Predict which combination of attributes will result in the highest percentage saturation of a group of proteins.

A) high affinity and low concentrations of ligand
B) low affinity and low concentrations of ligand
C) high affinity and high concentrations of ligand
D) low affinity and high concentrations of ligand

Question 68

Lipids derived from arachidonic acid are called ____.