Question 1

Which property of carbon most directly allows it to form large, complex, and diverse molecules essential for life?

Accepted Answer

Its four valence electrons, allowing four covalent bonds

Question 2

Stanley Miller's classic experiment demonstrated the abiotic synthesis of organic compounds. Which of the following best describes the significance of this experiment for our understanding of the origin of life?

Accepted Answer

It showed that simple molecules could spontaneously form complex organic compounds under early Earth conditions

Question 3

Which of the following best explains why carbon atoms can form molecules with a tetrahedral shape?

Accepted Answer

Carbon forms single covalent bonds with four other atoms, resulting in a tetrahedral geometry

Question 4

Consider the molecule ethene ($$C_2H_4). $$What is the spatial arrangement of the atoms joined to the carbons when the two carbon atoms are connected by a double bond?

Accepted Answer

The atoms joined to the carbons are in the same plane as the carbons

Question 5

Which of the following molecules is an example of a carbon atom partnering with atoms other than hydrogen?

Accepted Answer

Carbon dioxide ($$CO_2)$$

Question 6

Hydrocarbons are organic molecules consisting of only carbon and hydrogen. Which property makes them a major source of energy in biological systems?

Accepted Answer

Their covalent bonds store a large amount of energy that can be released during reactions

Question 7

Which of the following is NOT a type of isomer found in organic molecules?

Accepted Answer

Isotopic isomers

Question 8

A pharmaceutical company develops a new drug that exists as two enantiomers. Only one enantiomer is biologically active. What is the most likely reason for this?

Accepted Answer

Biological molecules are chiral and interact differently with each enantiomer

Question 9

Which functional group is responsible for the acidic properties of organic molecules such as acetic acid?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 10

Testosterone and estradiol are both steroids with a common carbon skeleton. What accounts for their different biological effects?

Accepted Answer

The presence and arrangement of different functional groups attached to the carbon skeleton

Question 11

Which of the following best describes the role of ATP in cellular processes?

Accepted Answer

ATP is the primary energy-transferring molecule in the cell

Question 12

What is the chemical reaction that releases energy from ATP for cellular work?

Accepted Answer

ATP + $$H_2O \rightarrow$$ ADP + inorganic phosphate ($$P_i) + $$energy

Question 13

Which of the following statements about cis-trans isomers is correct?

Accepted Answer

Cis-trans isomers differ in the spatial arrangement of atoms around a double bond

Question 14

A molecule contains a carbon atom bonded to four different atoms or groups. What type of isomerism can this carbon atom give rise to?

Accepted Answer

Enantiomerism (optical isomerism)

Question 15

Which functional group is most likely to be found in organic molecules that act as bases, such as amino acids?

Accepted Answer

Amino group ($$-NH_2$)

Question 16

Which of the following best explains why only one enantiomer of a drug may be effective in treating a disease?

Accepted Answer

The shape of the active site of biological molecules is specific to one enantiomer

Question 17

Which of the following is a correct example of a hydrocarbon?

Accepted Answer

Methane ($$CH_4)$$

Question 18

Which of the following statements about structural isomers is true?

Accepted Answer

Structural isomers have the same molecular formula but different covalent arrangements of their atoms

Question 19

Which functional group is most likely to be involved in energy transfer reactions in cells, such as those involving ATP?

Accepted Answer

Phosphate group ($$-PO_4$)

Question 20

Which of the following best describes the difference between butane and 2-methylpropane (isobutane)?

Accepted Answer

They are structural isomers with different branching of the carbon skeleton

Carbon: The Backbone of Life (Chapter 4) – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards