Question 1

Stanley Miller's experiment in 1953 demonstrated that organic molecules could form under conditions simulating early Earth. Which of the following best explains the significance of this experiment for our understanding of the origin of life?

Accepted Answer

It provided evidence that simple organic molecules necessary for life could form from inorganic precursors under early Earth conditions.

Question 2

Which functional group is characterized by a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group, and is commonly found in amino acids and fatty acids?

Accepted Answer

Carboxyl group

Question 3

A dehydration reaction joins two monosaccharides to form a disaccharide. What type of bond is formed between the two sugar molecules?

Accepted Answer

Glycosidic linkage

Question 4

Cellulose and starch are both polysaccharides composed of glucose monomers. Why can't human digestive enzymes hydrolyze cellulose?

Accepted Answer

Human enzymes cannot break the $$\beta-$$glycosidic linkages present in cellulose.

Question 5

Which of the following statements about lipids is correct?

Accepted Answer

Lipids are hydrophobic because they consist mostly of nonpolar hydrocarbon chains.

Question 6

Phospholipids are a major component of cell membranes. What property allows them to spontaneously form bilayers in water?

Accepted Answer

Their fatty acid tails are hydrophobic and their phosphate heads are hydrophilic.

Question 7

Which of the following is NOT a function of proteins in living organisms?

Accepted Answer

Storing genetic information

Question 8

A mutation changes a single amino acid in the active site of an enzyme. What is the most likely consequence?

Accepted Answer

The enzyme's ability to bind its substrate may be altered, potentially reducing or eliminating its activity.

Question 9

Which level of protein structure is primarily responsible for the unique three-dimensional shape of a functional protein?

Accepted Answer

Tertiary structure

Question 10

Hemoglobin is an example of a transport protein. What is its primary function in vertebrates?

Accepted Answer

Transporting oxygen from the lungs to other tissues

Question 11

Which of the following correctly describes the flow of genetic information in a cell according to the central dogma?

Accepted Answer

DNA $$\rightarrow$$ RNA $$\rightarrow$$ Protein

Question 12

Which of the following is a correct description of a nucleotide, the monomer of nucleic acids?

Accepted Answer

A nucleotide consists of a nitrogenous base, a phosphate group, and a five-carbon sugar.

Question 13

Which functional group is found in all amino acids and is responsible for their basic properties?

Accepted Answer

Amino group

Question 14

A triglyceride is formed by joining three fatty acids to one glycerol molecule. What type of reaction is responsible for this process?

Accepted Answer

Dehydration reaction

Question 15

Which of the following best explains why unsaturated fatty acids are liquid at room temperature?

Accepted Answer

Their double bonds create kinks, preventing tight packing.

Question 16

Which protein function is exemplified by antibodies?

Accepted Answer

Defense against disease

Question 17

Which of the following is a structural polysaccharide found in plant cell walls?

Accepted Answer

Cellulose

Question 18

Which functional group is commonly found in ATP and is critical for energy transfer in cells?

Accepted Answer

Phosphate group

Question 19

Which of the following statements about protein structure is correct?

Accepted Answer

The sequence of amino acids determines the protein's three-dimensional structure.

Question 20

Which of the following is a correct description of the double helix structure of DNA?

Accepted Answer

It consists of two polynucleotide strands spiraling around a common axis in opposite directions.

Macromolecules: Carbon and Life (Chapter 5) – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard