Module 1.1: Review on the Chemical Composition of an Organism

Question 1

True or False

Living organisms obey chemical and physical laws.

Answer 1

True

Question 2

Cells are based mainly on ___ compounds.

Answer 2

carbon

Question 3

True or False

Life depends largely on chemical reactions in NON-AQUEOUS solution of which organisms are composed of about 70% water.

Answer 3

False

AQUEOUS

Question 4

___ contributed to medical chemistry.

Answer 4

Jan Baptist van Helmont (1577–1644)

Question 5

___ made contributions on the chemical composition of some plant and animal materials as well as various drugs.

Answer 5

Karl Wilhelm Scheele (1742-1786)

Question 6

___ characterized the chemical composition of air, and studied the process of oxidation and the nature of animal. He is often considered as father of modern biochemistry.

Answer 6

Antoine Lavoisier (1743–1794)

Question 7

___ is a German biochemist who did extensive work characterizing carbohydrates, amino acids and fats, establishing some of their composition.

Answer 7

Hermann Emil Fisher (1852-1919)

Question 8

___ discovered nucleic acids.

Answer 8

Friedrich Miescher (1844-1895)

Question 9

___ discovered liver glycogen and showed its relation to blood sugar in health and disease as well as evaluated the digestive properties of pancreatic juice.

Answer 9

Claude Bernard (1813-1878)

Question 10

___ developed the concept of pH, a scale measuring the acidity and alkalinity of an aqueous solution.

Answer 10

Soren Sörensen (1868-1939)

Question 11

___ developed the ultracentrifuge.

Answer 11

Theodore Svedberg (LT, 1884-1971)

Question 12

___ made contributions on electrophoresis apparatus and chromatography.

Answer 12

Arne W. K. Tiselius (1902-1971)

Question 13

Carbon, hydrogen, oxygen, and nitrogen make up ___ of the total weight of living cells which in addition with phosphorus and sulfur make up more than 99%.

Answer 13

96.3%

Question 14

How much of each element does the human body consist of?

Hydrogen
Oxygen
Carbon
Nitrogen
Calcium
Phosphorus
Sulfur
Potassium
Sodium
Magnesium

Answer 14

Hydrogen - 60%
Oxygen - 22.5%
Carbon - 10.5%
Nitrogen - 2.4%
Calcium - 0.22%
Phosphorus 0.13%
Sulfur - 0.13%
Potassium - 0.03%
Sodium - 0.03%
Magnesium - 0.03%

Question 15

Enumerate the four (4) chemical bonds that are essential for life to exist.

Answer 15

1. ionic bonds
2. covalent bonds
3. hydrogen bonds
4. metallic bonds

Question 16

___, a bond in which a metal atom loses electron(s) to a nonmetal atom.

Answer 16

ionic bond

Question 17

___, a bond in which two nonmetal atoms share electrons.

Answer 17

covalent bond

Question 18

___, a bond in which H attacks an electronegative atom electrostatically.

Answer 18

hydrogen bond

Question 19

___, a bond in which positive metal ions attract conducting electrons.

Answer 19

metallic bond

Question 20

___ are weak intermolecular forces that are responsible for the attraction between molecules.

Answer 20

Van der Waals forces

Question 21

Van der Waals forces are named after the Dutch physicist ____, who first proposed their existence in 1873.

Answer 21

Johannes Diderik van der Waals

Question 22

A ___ is a molecule that is composed of a hydrophobic hydrocarbon chain to which is attached to a hydrophilic carboxylic acid group.

Answer 22

fatty acid

Question 23

True or False

In an aqueous environment, the hydrophobic tails of phospholipids pack together to exclude water.

Answer 23

True

Question 24

___ are the basis of cell membranes.

Answer 24

lipid bilayers

Question 25

What is the pH level inside the cell?

Answer 25

nearly 7

Question 26

In the cell, the free amino acid exists in its ____ form; but when it is incorporated into a polypeptide chain, the charges on the amino acid and carboxyl groups ____.

Answer 26

ionized;
disappear

Question 27

What happens if the noncovalent bonds maintaining the stable conformation most proteins and many RNA molecules fold into are disrupted?

Answer 27

the molecule becomes a flexible chain that usually has no biological value