Chemistry of Life

Question 1

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

Answer 1

Oxygen (O), Carbon (C), Hydrogen (H), Nitrogen (N)

Question 2

What are seven lesser elements found in the human body?

Answer 2

Calcium (Ca), Chlorine (Cl), Magnesium (Mg), Phosphorus (P), Potassium (K), Sulfur (S), Sodium (Na)

Question 3

What are two trace elements found in the human body?

Answer 3

Iodine (I), Iron (Fe)

Question 4

What three particles make an atom? What are their charges? Where are they found?

Answer 4

Protons (positive) - nuclei, Electrons (negative) - orbitals, Neutrons (no charge) - nuclei

Question 5

What are the four types of macromolecules?

Answer 5

Proteins, Lipids, Carbohydrates, Nucleic Acids

Question 6

What are ions?

Answer 6

Atoms that have a positive or negative charge

Question 7

What are molecules and why do they form?

Answer 7

Groups of atoms chemically bonded together in stable association. Form bonds to fill valence electron shells.

Question 8

What are the different types of chemical bonds?

Answer 8

Ionic bonds, Covalent bonds, Hydrogen bonds

Question 9

Ionic bonds

Answer 9

Chemical bond between atoms that gain or lose one or more electons.

Question 10

Covalent bonds

Answer 10

Non-polar: electrons are shared equally

Polar: electrons between atoms are not shared equally.

Question 11

Hydrogen bonds

Answer 11

Weak chemical bond created between molecules that have polar covalent bonds. Created by the partial charges created by an asymmetric internal distribution of charge, leading to partially positive and partially negative regions.

Question 12

Solution

Answer 12

Very small dissolved solutes (can be solids, liquids,

gases). Clear. Do not separate with time.

Question 13

Colloid

Answer 13

Medium sized solutes (often proteins in water).

Cloudy. Often gel-like. Do not separate with time.

Question 14

Supension

Answer 14

Large sized solutes “suspended” in solvent.

Cloudy to Opaque. Separate with time.

Question 15

What type of mixture is blood?

Answer 15

Blood is a complex mixture of more than one type. Solution of NaCl, colloid of proteins, suspension of cells.

Question 16

Hydrophylic

Answer 16

A charged or polar substance that interacts with and dissolves in water

Question 17

Hydrophobic

Answer 17

Nonpolar, uncharged substance (e.g.oils and fats) that do not interact well with water. They separate from it rather than dissolve in it

Question 18

The amphipathic lipids of cell membranes

are called.

Answer 18

Phospholipids. The two fatty acid “tails” of the molecule are hydrophobic, but the phosphate “head” is hydrophilic.

Question 19

What ions (electrolytes) are commonly found in the body?

Answer 19

Sodium (Na+), Potassium (K+), Chloride (Cl-), Calcium (Ca2+), Magnesium (Mg2+), Phosphate (-), and Iron(II)