Week 1: Atoms and Molecules

Question 1

Chemical Element

Answer 1

Pure substance that cannot be broken down any further by chemical means.

Question 2

What are the four most common chemical elements in the body?

Answer 2

Oxygen (65%), Carbon (18.5%), Hydrogen (9.5%), Nitrogen (3.2%)

Question 3

What is the importance of Oxygen in the body?

Answer 3

Major component of organic and inorganic molecules.
Ex: water; solvent in all body and cellular fluids and oxygen gas - cellular energy.
All Macromolecules.

Question 4

What is the importance of Carbon in the body?

Answer 4

Major component of Organic molecules such as: sugars, fats, proteins, nucleic acids.
Ex: Carbon Dioxide, Bicarbonate.

Question 5

What is the importance of Hydrogen in the body?

Answer 5

Component of all organic molecules and some inorganic molecules (water).
As in ion - influences acidity of bodily fluids.
Carbohydrates, Lipids, Proteins, Nucleic Acids.

Question 6

What is the importance of Nitrogen in the body?

Answer 6

Component of proteins (structural molecules and enzymes), nucleic acids (genetic material), and other important organic molecules.
Nitrogenous excretion products.

Question 7

Atom

Answer 7

The smallest unit of an element that still retains its physical and chemical properties of that element.

Question 8

3 Subatomic Particles: Name, mass, charge, location.

Answer 8

Electron (-) outside cell
Protons (+) nucleus
Neutrons (neutral) nucleus

Question 9

Electron Shell Amounts

Answer 9

1st: 2
2nd: 8
3rd: 18

Question 10

Effect of Subatomic Particles

Answer 10

Equal number of electrons and protons (roughly same number of neutrons - can vary); neutral charge.

Question 11

Molecule

Answer 11

When two or more atoms are joined together by chemical bonds.
Ex: 2 Oxygen = O2

Question 12

Compound

Answer 12

A molecule consisting of more than one type of element.
Ex: 2 Hydrogen + 1 Oxygen = H2O

Question 13

Stable Element Condition

Answer 13

Full valence (outer) shell, or containing 8 electrons.

Question 14

What happens to an unstable element?

Answer 14

Will gain or lose electrons by exchanging them with other elements - results in negative or positive charge

Question 15

Ion

Answer 15

Charged atoms

Question 16

Ionic Bond

Answer 16

When two oppositely charged ions are held together by electrostatic attraction for one another.
Common in most inorganic compounds.

Question 17

Covalent Bond

Answer 17

When electrons are shared between atoms (neither one loses or gains electrons)

Question 18

Double Covalent Bond

Answer 18

When two electron pairs are shared between two atoms.

Question 19

Inorganic Molecule

Answer 19

Does not always have Carbon (ex: CO2, HCO3)
Simple and small
Covalent or Ionic
Ex: H2O, NaCl, HCl, NaOH.

Question 20

Organic Molecule

Answer 20

Carbon
Large, complex
Covalent bonds
New bonds release energy - metabolism.
Body can carry out chemical reactions.
Ex: fats, sugars, proteins.

Question 21

Inorganic Compounds

Answer 21

Simple structure, usually lack Carbon.
Ex: water, most salts, acids, and bases.
Ex: Carbon Dioxide and Bicarbonate.

Question 22

Organic Compounds

Answer 22

Always have Carbon (often with Hydrogen).
Always contain covalent bonds.
Ex: carbohydrates, lipids, protein, and nucleic acids.

Question 23

Composition of Organic Molecules

Answer 23

Made by living organisms with Carbon as the core element.
Not soluble in water.
Primarily covalent bonds.

Question 24

Importance of Organic Molecules to Living Organisms

Answer 24

(Carbon) Can bond with hundreds of others to form large/complex molecules - allows body to build complex structures and carry out complex processes.
Not soluble in water - building materials (cell membranes)
Primarily covalent bonds - when broken give off energy. Stored energy.

Question 25

Examples of Organic Molecules

Answer 25

Macromolecules: glycogen, starch, lipids, proteins, nucleic acids, carbohydrates,

Question 26

Chemical Properties of Water

Answer 26

Inorganic compound consisting of one partially negatively charged oxygen atom covalently bonded to two partially positive charged hydrogen atoms.

Question 27

How do water molecules interact with each other?

Answer 27

Through weak hydrogen bonds between hydrogen of one atom to oxygen of another.

Question 28

Atomic Number

Answer 28

Number of protons in the nucleus of the atom.

Question 29

Mass Number

Answer 29

Sum of protons and neutrons in nucleus of an atom.

Question 30

Valence Shell

Answer 30

Outermost shell of an electron.

Question 31

Cation

Answer 31

A positively charged ion.

Question 32

Anion

Answer 32

A negatively charged ion.

Question 33

Compounds

Answer 33

Substance composed of two or more different elements joined by chemical bonds.

Question 34

Nonpolar

Answer 34

Molecule with electrons that are relatively equally shared in covalent bonds.

Question 35

Polar

Answer 35

Molecule with regions that have opposite charges; uneven number of protons in nuclei of atoms participating.
Ex: water.

Question 36

Dipole

Answer 36

Molecule with negatively charged portion separated from a positively charged portion. Forms a tent.

Question 37

Explain ionic bond between Sodium and Chlorine

Answer 37

Sodium - 11 electrons - one in valence shell
Chlorine - 17 electrons
Sodium readily gives up solo electron - now positively charged and vice versa.

Question 38

Emergent Properties

Answer 38

Function that was not present before and is a result of interactions.

Question 39

What is essential for all aerobic breakdown of glucose into ATP?

Answer 39

Oxygen.

Question 40

Isotopes

Answer 40

Atoms with same number of protons, but differing number of neutrons.
Different forms of a single element.

Question 41

Which bond is stronger: Covalent or Ionic?

Answer 41

Covalent.
Release energy when formed, require energy to break.

Question 42

Hydrogen Bond

Answer 42

When a polar molecule weakly bonds with another polar molecule.
Ex: water.