Chemistry Quizz

1.

Which of the following molecules orient themselves into sandwichlike membranes because of hydrophobic components within the molecule?

A.

Amylose
B.

Glycogen
C.

Cellulose
D.

Phospholipid
E.

Protein

Correct Answer
D. Phospholipid

Explanation
Phospholipids are composed of glycerol molecules bonded to two fatty acids and one phosphate group. The
phosphate group is a hydrophilic “head” and the long hydrocarbon chains of fatty acids are hydrophobic “tails.”
In cell membranes, phospholipids orient themselves into two layers, with the hydrophobic tails pointing to the
inside of the “sandwich.”

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2.

Each of the following molecules is a polymer EXCEPT:

A.

Protein
B.

Glucose
C.

Cellulose
D.

Starch
E.

Glycogen

Correct Answer
B. Glucose

Explanation
Glucose is a monomer consisting of a single glucose molecule. Starch, glycogen, and cellulose are polymers
consisting of repeating units of glucose. Protein is a polymer of amino acids.

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3.

Hydrophilic properties are characteristic of all of the following EXCEPT:

A.

Polar molecules
B.

Molecules soluble in water
C.

Molecules that readily ionize in water
D.

The long hydrocarbon chain components of some molecules
E.

The hydroxyl group

Correct Answer
D. The long hydrocarbon chain components of some molecules

Explanation
Long hydrocarbon chains are nonpolar and, therefore, hydrophobic. Any polar molecule (or polar group
of atoms like the hydroxyl group) is hydrophilic. When a substance ionizes in water, it dissolves; thus, it is
hydrophilic

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4.

All of the following are carbohydrates EXCEPT:

A.

Polypeptide
B.

Glycogen
C.

Amylose
D.

Glucose
E.

Polysaccharide

Correct Answer
A. Polypeptide

Explanation
A polypeptide is a protein. Amylose is a starch and, therefore, a carbohydrate

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5.

A great number of natural organic molecules can exist because carbon atoms can:

A.

Form four ionic bonds
B.

Form four covalent bonds
C.

Lose four electrons to form compounds
D.

React with enzymes
E.

Number, kind and arrangement of atoms in a molecule

Correct Answer
B. Form four covalent bonds