Lesson 1.1 - The Fundamental Chemistry Of Life

Question 1

What parts of the body do PET scans commonly evaluate?

Answer 1

PET scans are often used to evaluate nearly the entire body. They work well with anything from the base of the skull to the mid-thighs.

Question 2

Can a reduction reaction occur independently of an oxidation reaction, or vice versa? Why or why not?

Answer 2

The reduction or oxidation of one molecule always implies the oxidation or reduction of another molecule; they cannot occur independently.

Question 3

There are four types of chemical bonds in biochemistry: _____, _____, _____, and _____.

Answer 3

There are four types of chemical bonds in biochemistry: ionic, covalent bonds, hydrogen bonds, and weak van der Waals forces.

Question 4

[Ionic bonds] form between two ions (which are atoms that lost or gained electrons), specifically between a _____ (positively charged ion) and an _____ (a negatively charged ion).

Answer 4

[Ionic bonds] form between two ions (which are atoms that lost or gained electrons), specifically between a cation (positively charged ion) and an anion (a negatively charged ion).

Question 5

For all three isotopes of carbon, what is the same?

Answer 5

Protons & Electrons

Question 6

[Covalent bonds] form when atoms _____ one or more pairs of valence electrons.

Answer 6

[Covalent bonds] form when atoms share one or more pairs of valence electrons.

Question 7

Define Intermolecular Force

Answer 7

Force of attraction between two molecules.

Question 8

The radiation [from radioactive decay] may damage molecules in living cells, however, some are useful in _____ process to determine the age of organic material or in _____applications.

Answer 8

The radiation [from radioactive decay] may damage molecules in living cells, however, some are useful in geological process to determine the age of organic material or in medical applications.

Question 9

What is a form of an element that differs in its number of neutrons known as?

Answer 9

Isotope

Question 10

[Non-polar covalent bonds are] formed between atoms that have similar _____ (electrons are equally shared).

Answer 10

[Non-polar covalent bonds are] formed between atoms that have similar electronegativities (electrons are equally shared).

Question 11

What will patients requiring a PET scan do after they are injected with a glucose solution?

Answer 11

The patient will wait as the injected glucose has to spread through the body through regular metabolic activity of the body. They will rest quietly and avoid muscle movement or talking so that all muscles and the vocal chords will appear normal on the scans.

Question 12

As ¹⁴C decays, one neutron splits into a _____ and a _____.

Answer 12

As C¹⁴ decays, one neutron splits into a high-energy electron and a proton.

Question 13

What harmful growth will show up on a PET scan?

Answer 13

Malignant Tumour (due to rapid cell division using up glucose)

Question 14

For all three isotopes of carbon, what is different?

Answer 14

Neutrons

Question 15

Define Hydrolysis Reaction

Answer 15

A chemical reaction in which water is used as a reactant to split a larger molecule into smaller subunits.

Question 16

An atom has no net charge because the number of _____ is equal to the number of _____.

Answer 16

An atom has no net charge because the number of protons is equal to the number of electrons.

Question 17

What does X represent in standard atomic notation?

Answer 17

Chemical symbol for the element.

Question 18

An atom has eight electrons and six of these electrons are valence electrons. What is the name of the element?

Answer 18

Oxygen

Question 19

Intermolecular forces are attractive forces _____ molecules.

Answer 19

Intermolecular forces are attractive forces between molecules.

Question 20

Atoms with energy shells that are not completely filled are chemically _____.

Answer 20

Atoms with energy shells that are not completely filled are chemically reactive.

Question 21

Define Dehydration Reaction

Answer 21

A chemical reaction in which subunits of a larger molecule are joined by the removal of water. Also called a condensation reaction.

Question 22

What is an attractive force between a partially positively charged hydrogen atom, and a partially negatively charged atom in another molecule known as?

Answer 22

Hydrogen Bond

Question 23

Compare ionic bonds with covalent bonds.

Answer 23

Ionic bonds form when an electron is transferred from one atom to another, and the resulting ions are attracted to each other. Covalent bonds form when atoms share electrons to fill their valence shell.

Question 24

The rest of the elements [that make up the weight of a living organism] are found in such small amount (<0.1%) that they are called _____. (ex. iodine and iron)

Answer 24

The rest of the elements [that make up the weight of a living organism] are found in such small amount (<0.1%) that they are called trace elements. (ex. iodine and iron)

Question 25

Electron orbitals are grouped into _____ or _____ and are numbered 1, 2, 3, etc., indicating their relative distance from the nucleus.

Answer 25

Electron orbitals are grouped into energy levels or energy shells and are numbered 1, 2, 3, etc., indicating their relative distance from the nucleus.

Question 26

What is the measure of an atom’s attraction to shared electrons known as?

Answer 26

Electronegativity

Question 27

In a bond between nitrogen (with an electronegativity of 3.0) and hydrogen (with an electronegativity of 2.2), which atom will the electrons be closer to? Explain your reasoning.

Answer 27

Nitrogen has a higher electronegativity than hydrogen, so the electrons will be closer to the nitrogen atom

Question 28

The strength of a covalent bond depends on the _____ (the measure of an atom’s attraction for additional electrons) of the atoms involved.

Answer 28

The strength of a covalent bond depends on the electronegativity (the measure of an atom’s attraction for additional electrons) of the atoms involved.

Question 29

Oxidation is the _____ of electrons, and reduction is the _____ of electrons. The oxidation of one molecule or atom is always linked to the reduction of another molecule or atom. This is called a _____ reaction.

Answer 29

Oxidation is the loss of electrons, and reduction is the gain of electrons. The oxidation of one molecule or atom is always linked to the reduction of another molecule or atom. This is called a redox reaction.

Question 30

How does radiocarbon dating work?

Answer 30

Measures the amount of ¹⁴C left in the object by using a device to measure the amount of ß particles given off as the ¹⁴C decays.

Question 31

How do bonding arrangements in a molecule affect the shape of the molecule?

Answer 31

Although answers may vary, one sample answer is: To minimize their energy, electron pairs in atoms move as far away from each other as possible, which causes the bonds to be at different angles from one another.

Question 32

List the three common isotopes of hydrogen.

Answer 32

The three common isotopes of hydrogen are ¹H (protium or hydrogen), ²H (deuterium), and ³H (tritium).

Question 33

Describe reduction and oxidation.

Answer 33

Reduction is the gain of electrons by a molecule and oxidation is the loss of electrons by a molecule.

Question 34

The decay process transforms an unstable, radioactive isotope (called _____) into an atom of another element.

Answer 34

The decay process transforms an unstable, radioactive isotope (called radioisotope) into an atom of another element.

Question 35

_____ are the electrons in the outermost electron shell of an atom.

Answer 35

Valence electrons are the electrons in the outermost electron shell of an atom.

Question 36

Define Ionic Bond

Answer 36

A bond that results from the attraction between two oppositely charged atoms or molecules.

Question 37

_____ is composed of elements.

Answer 37

Matter is composed of elements.

Question 38

_____ is the removal of -OH and -H from two reactant molecules to form a _____ and _____.

Answer 38

Dehydration is the removal of -OH and -H from two reactant molecules to form a larger molecule and water.

Question 39

What is a partial positive or negative charge at the ends of a molecule known as?

Answer 39

Polarity

Question 40

How are radioisotopes used in scientific research and medicine?

Answer 40

Radioisotopes are used as tracer molecules for medical diagnostics and for scientific studies involving transportation of metabolism of molecules of interest.

Question 41

Because isotopes of the same element have the same number of _____ and _____, they behave exactly the same in a chemical reaction.

Answer 41

Because isotopes of the same element have the same number of protons and electrons, they behave exactly the same in a chemical reaction.

Question 42

What does a CT scan get an image of?

Answer 42

An image of the body’s internal anatomy.

Question 43

_____ is a measure of an atom’s attraction for electrons. Differences in _____ results in bond polarity.

Answer 43

Electronegativity is a measure of an atom’s attraction for electrons. Differences in electronegativitiy results in bond polarity.

Question 44

[Radiopharmaceuticals] emit _____ that can be detected externally by special types of cameras; these cameras work in conjunction with computer systems to convert the _____ into images and information about the area of the body being examined.

Answer 44

[Radiopharmaceuticals] emit gamma rays that can be detected externally by special types of cameras; these cameras work in conjunction with computer systems to convert the gamma rays into images and information about the area of the body being examined.

Question 45

What is an electron in the outermost energy level or shell of an atom known as?

Answer 45

Valence Electron

Question 46

What happens when patients first arrive for their PET scan?

Answer 46

Patients go early and have an injection (usually into the hands) of a glucose solution with a radioactive tracer.

Question 47

Define Cation

Answer 47

An ion that has a positive charge.

Question 48

Define Anion

Answer 48

An ion that has a negative charge.

Question 49

What is a region of space that is occupied by electrons located around the nucleus of an atom known as?

Answer 49

Orbital

Question 50

What is the atomic number and mass number of Carbon-14?

Answer 50

Atomic Number - 6

Mass Number - 14

Question 51

Define Polarity

Answer 51

Partial positive or negative charge at the ends of a molecule.

Question 52

One atom has 6 protons and a mass number of 13. Another atom has 6 protons and a mass number of 15. Explain why there is a difference in the mass numbers.

Answer 52

The difference in the mass numbers is because one atom has 2 more neutrons in its nucleus than the other.

Question 53

Define Neutralization Reaction

Answer 53

A reaction in which an acid and a base combine to create a salt and water.

Question 54

What is the force of attraction between two molecules known as?

Answer 54

Intermolecular Force

Question 55

When two atoms with significantly different electronegativities share electrons, the electrons are more attracted to the atom with the higher electronegativity, therefore they are more likely to be found near the one side (_____).

Answer 55

When two atoms with significantly different electronegativities share electrons, the electrons are more attracted to the atom with the higher electronegativity, therefore they are more likely to be found near the one side (unequal sharing).

Question 56

What does A represent in standard atomic notation?

Answer 56

The mass number.

A = number of protons + number of neutrons

Question 57

_____ occurs when a bond in a large molecule is broken, and water is added to the resulting subunits.

Answer 57

Hydrolysis occurs when a bond in a large molecule is broken, and water is added to the resulting subunits.

Question 58

[In polar covalent bonds, the] atom with higher electronegativity has a partial _____ charge and the atom with lower electronegativity has a partial _____ charge.

Answer 58

[In polar covalent bonds, the] atom with higher electronegativity has a partial negative charge and the atom with lower electronegativity has a partial positive charge.

Question 59

[_____ forces are] momentary attractions of the electrons of one molecule to the nuclei of another molecule.

Answer 59

[Van der Waals forces are] momentary attractions of the electrons of one molecule to the nuclei of another molecule.

Question 60

What is an ion that has a positive charge known as?

Answer 60

Cation

Question 61

What carbon isotope comes from N in the atmosphere being hit by cosmic rays?

Answer 61

Carbon-14

Question 62

How does ¹⁴C get into the body of living things?

Answer 62

Some CO₂ has ¹⁴C as the carbon atom, through photosynthesis, this carbon enters the body of living things.

Question 63

There are about 21 other elements found in living organisms, but these four [main] elements [of organic compounds] make up _____% of the weight of a living organism.

Answer 63

There are about 21 other elements found in living organisms, but these four [main] elements [of organic compounds] make up 96% of the weight of a living organism.

Question 64

What carbon isotope makes up about 99% of all naturally occuring carbon?

Answer 64

Carbon-12

Question 65

What type of scans are PET scans commonly combined with? Why?

Answer 65

CT (computerized tomography) Scan

When combined, it more precisely aligns the activity (PET) to where in the body it is happening (CT).

Question 66

All organic (_____ containing) compounds in living organisms are composed primarily of three elements: _____, _____, and _____. As well, they often include _____.

Answer 66

All organic (carbon containing) compounds in living organisms are composed primarily of three elements: carbon, hydrogen, and oxygen. As well, they often include nitrogen.

Question 67

What is a bond that results from the attraction between two oppositely charged atoms or molecules known as?

Answer 67

Ionic Bond

Question 68

Ions are very strongly attracted to water molecules and tend to dissociate and dissolve in water, forming _____.

Answer 68

Ions are very strongly attracted to water molecules and tend to dissociate and dissolve in water, forming hydrated ions.

Question 69

Define Isotope

Answer 69

A form of an element that differs in its number of neutrons.

Question 70

Define Polar Covalent Bond

Answer 70

A bond between two atoms, made up of enequally shared electrons

Question 71

What carbon isotope makes up almost 1% of all naturally occuring carbon?

Answer 71

Carbon-13

Question 72

What is an electron transfer reaction known as?

Answer 72

Redox Reaction

Question 73

What is an ion that has a negative charge known as?

Answer 73

Anion

Question 74

All atoms of the same element have the same number of _____ (and therefore defines its elemental identity), but they may have different numbers of _____ in the nucleus. This means that atoms with the same atomic number can have different atomic masses, we call these _____.

Answer 74

All atoms of the same element have the same number of protons (and therefore defines its elemental identity), but they may have different numbers of electrons in the nucleus. This means that atoms with the same atomic number can have different atomic masses, we call these isotopes.

Question 75

How do hydrogen bonds influence the physical properties of water?

Answer 75

Hydrogen bonds give water a high heat capacity, high melting and boiling points, and high surface tension, cohesion and adhesion.

Question 76

_____ are different forms of the same element, with different numbers of neutrons. A _____ is an unstable _____ that decays to release particles.

Answer 76

Isotopes are different forms of the same element, with different numbers of neutrons. A radioisotope is an unstable isotope that decays to release particles.

Question 77

One atom has 6 protons and a mass number of 13. Another atom has 6 protons and a mass number of 15. Identify each of the atoms.

Answer 77

Both atoms are isotopes of carbon: ¹³C and ¹⁵C

Question 78

What are the very weak attractions between two molecules, or parts of molecules when they are close together, known as?

Answer 78

Van Der Waals Forces

Question 79

What are radioisotopes?

Answer 79

Radioisotopes are unstable forms of an atom that decay into other atoms by releasing energy and particles.

Question 80

Describe dehydration and hydrolysis. How are these two types of reactions related?

Answer 80

Dehydration is the removal of –OH and –H from two reactant molecules, which allows the reactant molecules to form a bond, as well as creating water. Hydrolysis is the breaking of a bond between two subunits and the addition of water in the form of –OH and –H to the subunits. Dehydration is the reverse of hydrolysis, and vice versa.

Question 81

_____ are the electrons in an atom’s outermost energy shell (or valence shell).

Answer 81

Valence electrons are the electrons in an atom’s outermost energy shell (or valence shell).

Question 82

Atoms of _____ elements, such as helium, neon, and argon, occur naturally in single atom form.

Answer 82

Atoms of inert elements, such as helium, neon, and argon, occur naturally in single atom form.

Question 83

_____ makes up everything in the universe, including all living things.

Answer 83

Matter makes up everything in the universe, including all living things.

Question 84

Define Valence Electron

Answer 84

An electron in the outermost energy level or shell of an atom.

Question 85

Atoms of reactive elements combine with each other to form _____ through stable attractions called chemical bonds.

Answer 85

Atoms of reactive elements combine with each other to form compounds through stable attractions called chemical bonds.

Question 86

What is a chemical reaction in which subunits of a larger molecule are joined by the removal of water known as?

Answer 86

Dehydration Reaction (Condensation Reaction)

Question 87

How do polar covalent bonds and non-polar covalent bonds differ?

Answer 87

Electrons are not shared equally in a polar covalent bond while electrons are shared relatively equally in non-polar covalent bonds.

Question 88

Define Radioisotope

Answer 88

A radioactive isotope of an element.

Question 89

What is the atomic number and mass number of Carbon-13?

Answer 89

Atomic Number - 6

Mass Number - 13

Question 90

Define Hydrogen Bond

Answer 90

Attractive force between a partially positively charged hydrogen atom, and a partially negatively charged atom in another molecule.

Question 91

What organs show up fluorescent on a PET scan?

Answer 91

The heart, kidneys, bladder and brain show up bright on the scan.

Question 92

What is a chemical reaction in which water is used as a reactant to split a larger molecule into smaller subunits known as?

Answer 92

Hydrolysis Reaction

Question 93

Atoms with completely filled outermost energy shells are chemically _____.

Answer 93

Atoms with completely filled outermost energy shells are chemically non-reactive.

Question 94

In what ways do hydrogen bonds produce attractive forces between molecules?

Answer 94

Hydrogen bonds produce attractive forces by lining up partially positively charged hydrogen atoms with a partially negative charged atoms of different molecules.

Question 95

Define Orbital

Answer 95

A region of space that is occupied by electrons located around the nucleus of an atom.

Question 96

What does Z represent in standard atomic notation?

Answer 96

The atomic number (number of protons).

Question 97

Electrons move around the atomic nucleus in specific regions called _____, which is a region of space that one or two electrons (two electrons are more stable) can occupy.

Answer 97

Electrons move around the atomic nucleus in specific regions called orbitals, which is a region of space that one or two electrons (two electrons are more stable) can occupy.

Question 98

What does PET stand for?

Answer 98

Positron Emission Tomography

Question 99

What is a bond between two atoms, made up of enequally shared electron known as?

Answer 99

Polar Covalent Bond

Question 100

The nuclei of some isotopes of an element are unstable and tend to break down, or _____, giving particles of matter that can be detected as _____.

Answer 100

The nuclei of some isotopes of an element are unstable and tend to break down, or decay, giving particles of matter that can be detected as radioactivity.

Question 101

Radioactive decay continues at a _____, with a constant proportion of _____ atoms breaking down during a given time interval.

Answer 101

Radioactive decay continues at a steady rate, with a constant proportion of radioisotope atoms breaking down during a given time interval.

Question 102

Define Van Der Waals Forces

Answer 102

Very weak attractions between two molecules, or parts of molecules when they are close together.

Question 103

Why is radiocarbon dating not accurate for objects that died from 1950 or later?

Answer 103

Humans started doing nuclear testing in the 50’s and therefore changed the known concentration of ¹⁴C in the atmosphere.

Question 104

[_____ are formed when there is an] attractive force between a partially positively charged hydrogen atom, and a partially negatively charged atom in another molecule. [They are] represented by a dotted line to distinguish it from the stronger covalent bond.

Answer 104

[Hydrogen bonds are formed when there is an] attractive force between a partially positively charged hydrogen atom, and a partially negatively charged atom in another molecule. [They are] represented by a dotted line to distinguish it from the stronger covalent bond.

Question 105

Define Electronegativity

Answer 105

The measure of an atom’s attraction to shared electrons.

Question 106

What does a PET scan get an image of?

Answer 106

An image of metabolic or biochemical activity.

Question 107

What is an element?

Answer 107

An element is a pure substance that can’t be broken down into simpler substances using ordinary chemical or physical techniques.

Question 108

What do we use radiocarbon dating for?

Answer 108

We use it to determine the relative age of a living things.

Question 109

Define Redox Reaction

Answer 109

An electron transfer reaction.

Question 110

What is a reaction in which an acid and a base combine to create a salt and water known as?

Answer 110

Neutralization Reaction

Question 111

What is a radioactive isotope of an element known as?

Answer 111

Radioisotope

Question 112

What is the atomic number and mass number of Carbon-12?

Answer 112

Atomic Number - 6

Mass Number - 12

Question 113

Oxygen plays a major role in biological molecules. Explain how oxygen plays a role in polarity, bond shape, and redox reactions.

Answer 113

Oxygen has a very high electronegativity, so it strongly attracts electrons of other elements and forms polar bonds. Oxygen has two pairs of non-bonding electrons in its out orbital and therefore forms two bonds that are not aligned—oxygen produces “bent” molecules. Oxygen also plays a role in redox reactions. It is frequently the oxidizing reagent because of its strong electronegativity in a reaction.

Question 114

Most of the other _____% [of the weight of a living organism] is composed of only seven other elements: calcium, phosphorus, potassium, sulphur, sodium, chlorine, and magnesium.

Answer 114

Most of the other 4% [of the weight of a living organism] is composed of only seven other elements: calcium, phosphorus, potassium, sulphur, sodium, chlorine, and magnesium.

Question 115

How can the atomic composition and shape of a molecule affect its polarity?

Answer 115

For a molecule to be polar is must contain atoms that differ in electronegativity and the resulting electronegative bonds must be arranged asymmetrically in the molecule. The asymmetrical shape of a molecule containing polar bonds can result in an overall unbalanced distribution of charge, making the molecule as a whole polar.

Question 116

[Nuclear medicine] uses substances called _____ (radioactive atom & compound), that are attracted to specific organs, bones, or tissues (can be inhaled, injected or taken orally).

Answer 116

[Nuclear medicine] uses substances called radiopharmaceuticals (radioactive atom & compound), that are attracted to specific organs, bones, or tissues (can be inhaled, injected or taken orally).

Question 117

[Nuclear medicine] is used to both _____ and _____ diseases such as: cancers, heart disease, renal disorders, thyroid disorders and neurological disorders.

Answer 117

Nuclear medicine is used to both diagnose and treat diseases such as: cancers, heart disease, renal disorders, thyroid disorders and neurological disorders.