Ch1 Adaptive Quiz: The Foundations of Biochemistry

Which cellular component is NOT an organelle?

A. mitochondria

B. Golgi complex

C. lysosome

D. ribosome

Ribosome

Which element is considered one of the trace elements required for human life?

A. lithium

B. fluorine

C. oxygen

D. zinc

D. Zinc

Compared to the uncatalyzed reaction, which parameters change in the presence of an enzyme?

A. ΔH°

B. ΔG‡

C. K_eq

D. ΔG°

B. ΔG‡

Which nucleotide is NOT found in DNA?

A. thymine

B. guanine

C. adenine

D. cytosine

E. uracil

E. uracil

What fuel source did the earliest organisms presumably utilize?

A. nitrogen and ammonia

B. methane

C. carbon monoxide and carbon dioxide

D. ferrous sulfide and ferrous carbonate

D. ferrous sulfide and ferrous carbonate

What do photoautotrophs use for their carbon source?

A. carbon dioxide

B. oxygen

C. sun

D. organic compounds

A. carbon dioxide

One of the important functional groups in biomolecules include _____, contained in acetyl-coenzyme A.

A. lipids

B. thioesters

C. nucleic acids

D. carbons

B. Thioesters

For the reaction (as written left to right) of glucose with oxygen, C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O energy is _____, and entropy _____.

A. absorbed; decreases

B. released; decreases

C, released; increases

D. absorbed; increases

C. released; increases

Which scenario BEST describes the order of events that occurs during gene expression?

A.DNA → RNA → natively folded protein → unfolded protein

B. RNA → DNA → unfolded protein → natively folded protein

C. RNA → DNA → natively folded protein → unfolded protein

D. DNA → RNA → unfolded protein → natively folded protein

D. DNA → RNA → unfolded protein → natively folded protein

Which aerobic bacteria may have been the precursor for chloroplasts?

A. methanogens

B. sulfur bacteria

C. cyanobacteria

D. purple bacteria

C. cyanobacteria

Which interaction is BEST studied in vitro rather than observing the complete picture in vivo?

A. specific ligand determination for a particular enzyme

B. cofactor determination for enzyme activity

C. multienzyme complex interactions

D. interactions between biomolecules

E. macromolecule diffusion through the cytosol

A. specific ligand determination for a particular enzyme

Louis Pasteur studied the optical activity of paratartaric acid found in wine casks. What terms did he coin to describe their observed rotation in plane-polarized light?

A. plus, minus

B. levorotatory, dextrorotatory

C. rectus, sinister

D. clockwise, counterclockwise

B. levorotatory, dextrorotatory

Which statement regarding energy flow in living organisms is false?

A. Autotrophs and heterotrophs are interdependent.

B. Virtually all cellular energy transductions involve moving electrons from high to low electrochemical potential.

C. Autotrophs exemplify a closed system.

D. Nearly all living organisms derive their energy from the sun, directly or indirectly.

C. Autotrophs exemplify a closed system.

What is the amazing fact about DNA replication?

A/ The E. coli genetic material is a single molecule consisting of 3 billion nucleotide pairs.

B. The human embryo consists of 4.64 million nucleotide pairs.

C. The averaged behavior of DNA generally produces identical progeny through cell division.

D. A single molecule replicates absolutely perfectly, generating identical progeny through cell division.

D. A single molecule replicates absolutely perfectly, generating identical progeny through cell division.

Which statement is true regarding the use of DNA molecules as historical records?

A. DNA is not a complete record as many mutations must have been erased or written over in the course of evolution.

B. RNA molecules are a better source of biological history than DNA.

C. Additional copies of genes hinder the use of DNA as a historical record.

D. The frequency of errors in the DNA taint the historicity of the record.

A. DNA is not a complete record as many mutations must have been erased or written over in the course of evolution.

In terms of the required energy source and carbon source, how would you categorize the fermentative bacteria Lactococcus lactis?

A. chemoheterotroph

B. chemoautotroph

C. photoheterotroph

D. photoautotroph

A. chemoheterotroph

What is the purpose of homologs?

A. They produce cellular structures that look the same but have different functions.

B. They allow cellular structures that look different to have the same function.

C. They produce dominant or recessive traits in progeny.

D. They allow for the determination of phylogenetic relationships.

D. They allow for the determination of phylogenetic relationships.

What is the standard free-energy change for a reaction at 25 °C if the equilibrium constant is 5.0 × 10²? ΔG^∘=−RTlnK

A. 15.4 kJ/mol

B. −1.3 kJ/mol

C. −15.4 kJ/mol

D. 1.3 kJ/mol

C. −15.4 kJ/mol

What is NOT one of the possible outcomes for an improperly repaired mutation?

A. The cell may undergo immediate cytolysis.

B. A daughter cell may have a defective enzyme for a metabolically essential reaction.

C. The daughter cell may not be viable.

D. The organism may be better equipped to survive in a particular environment.

A. The cell may undergo immediate cytolysis.

Which statement does NOT describe a benefit to enzyme-catalyzed reactions?

A. Enzymes lower the activation barrier for the transition state.

B. Enzymes increase reaction rate 10⁶ times compared to uncatalyzed reactions.

C. Enzymes orient the substrate molecules to favor stereospecific interactions.

D. Enzymes reduce the free-energy change of a reaction.

D. Enzymes reduce the free-energy change of a reaction.

If a cell homogenate was subject to centrifugation at increasingly higher speeds, in which order would you expect to see these components in the pellet?

A. mitochondria, ribosomes, whole cells

B. mitochondria, whole cells, ribosomes

C. nucleus, microsomes, mitochondria

D. whole cells, mitochondria, ribosomes

E. microsomes, mitochondria, whole cells

D. whole cells, mitochondria, ribosomes

Which statement is false regarding the cellular cytoskeleton?

A. Cytoskeletal filaments are permanent fixtures within the cell.

B. The cytoskeleton consists of actin filaments, microtubules, and intermediate filaments.

C. Organelles relocate in the cytoplasm by moving along cytoskeletal filaments.

D. Cytoskeleton filaments enable mitosis, cytokinesis, and amoeboid movement.

A. Cytoskeletal filaments are permanent fixtures within the cell.

In Miller and Urey's experiment, what identifiable products existed in the water phase?

A. amino acids and other organic molecules

B. hydrogen cyanide and amino acids

C. hydroxyl acids and aldehydes

D. amino acids, other organic molecules, hydrogen cyanide, hydroxy acids, and aldehydes

D. amino acids, other organic molecules, hydrogen cyanide, hydroxy acids, and aldehydes

Which statement is false regarding the systems biology explanation of cellular metabolism?

A. Regulation of each reaction sequence minimizes energy expenditure while providing for cellular needs.

B. Living cells continuously synthesize thousands of different kinds of carbohydrate, fat, protein, and nucleic acid molecules.

C. Metabolism is the sum of many interconnected reaction sequences.

D. A change in the concentration of any one metabolite affects the flow of materials through other pathways.

B. Living cells continuously synthesize thousands of different kinds of carbohydrate, fat, protein, and nucleic acid molecules.

Which property does NOT support the idea that RNA may have been the first genes and catalysts?

A. DNA transcription results in the formation of RNA.

B. The process of RNA self-replication is not perfect, enabling the formation of RNA variants.

C. RNA molecules can catalyze their own formation.

D. RNA-like molecules can form abiotically.

A. DNA transcription results in the formation of RNA.

The equilibrium constant is 5.0 × 10² for the reaction A → B + C. If the cellular concentrations are [A] = 8 mM, [B] = 0.3 mM, and [C] = 7 mM, is this cell at equilibrium?K_eq." style="box-sizing: border-box; border: 0px; vertical-align: baseline; margin: 0px 15px 0px 2px; padding: 0px; font: inherit; height: 22px; width: 22px; float: left;">

A. No, the mass-action ratio is smaller than the K_eq.

B. No, the mass-action ratio is larger than the K_eq.

C, Yes, the mass-action ratio is equal to the K_eq.

D. Yes, the mass-action ratio is equal to 1.

A. No, the mass-action ratio is smaller than the K_eq.

Which statement is true regarding the daughter DNA formed during replication?

A. It contains one parental strand of DNA and one newly synthesized strand of RNA.

B. Both strands are newly synthesized in each daughter cell.

C. It contains one parental strand of DNA and one newly synthesized strand of DNA.

D. Each daughter has only one parental DNA strand.

C. It contains one parental strand of DNA and one newly synthesized strand of DNA.