Q: A scientist is studying a solution with a hydrogen ion concentration of $$[H^+] = 1 \times 10$$^{-5}$$\ \mathrm{M}. $$What is the pH of this solution?

$$\mathrm{pH} = -\log_{10}(1 \times 10$$^{-5}$$) = 5$$

Question 1

Which of the following best explains why water is an effective temperature buffer in living organisms?

Accepted Answer

Water has a high specific heat due to hydrogen bonding, allowing it to absorb or release large amounts of heat with only a slight change in its own temperature.

Question 2

A scientist is studying a solution with a hydrogen ion concentration of $$[H^+] = 1 	imes 10$$^{-5}$$\ \mathrm{M}. $$What is the pH of this solution?

Accepted Answer

$$\mathrm{pH} = -\log_{10}(1 	imes 10$$^{-5}$$) = 5$$

Question 3

Which of the following statements about chemical equilibrium is correct?

Accepted Answer

At equilibrium, the rates of the forward and reverse reactions are equal, but the concentrations of reactants and products are not necessarily equal.

Question 4

A buffer solution contains a weak acid and its conjugate base. What happens when a small amount of strong acid is added to this buffer?

Accepted Answer

The buffer will accept the added $$H^+$$ ions, minimizing the change in pH.

Question 5

Which of the following best describes the difference between a polar covalent bond and a hydrogen bond?

Accepted Answer

A polar covalent bond involves unequal sharing of electrons within a molecule, while a hydrogen bond is an attraction between a partially positive hydrogen and an electronegative atom on another molecule.

Question 6

A patient is diagnosed with a genetic disorder that affects the folding of a protein, but the amino acid sequence remains unchanged. Which level of protein structure is most directly affected?

Accepted Answer

Tertiary structure

Question 7

Which of the following is a correct comparison between starch and cellulose?

Accepted Answer

Starch is composed of alpha-linked glucose units and is digestible by humans, while cellulose is composed of beta-linked glucose units and is not digestible by humans.

Question 8

A solution is prepared by dissolving 0.5 moles of NaCl in enough water to make 1 liter of solution. What is the molarity of the solution?

Accepted Answer

$$M = \frac{0.5\ \mathrm{mol}}{1\ \mathrm{L}} = 0.5\ \mathrm{M}$$

Question 9

Which of the following functional groups is most likely to act as a base in an aqueous solution?

Accepted Answer

Amino group ($$-NH_2$)

Question 10

Which of the following best explains why phospholipids form bilayers in aqueous environments?

Accepted Answer

Phospholipids are amphipathic, with hydrophilic heads that interact with water and hydrophobic tails that avoid water, leading to bilayer formation.

Question 11

A DNA molecule contains 30% adenine (A). According to base-pairing rules, what percentage of guanine (G) would you expect?

Accepted Answer

20%

Question 12

Which of the following is a property of saturated fatty acids that distinguishes them from cis unsaturated fatty acids?

Accepted Answer

Saturated fatty acids have no carbon–carbon double bonds and pack more tightly, making them solid at room temperature.

Question 13

Which of the following best describes the role of enzymes in biological reactions?

Accepted Answer

Enzymes lower the activation energy of reactions, increasing the rate without being consumed.

Question 14

A researcher adds a strong base to a beaker of pure water at 25°C, increasing the $$[OH^-] to$$ $$1 	imes 10$$^{-3}$$\ \mathrm{M}. $$What is the resulting $$[H^+]$$?

Accepted Answer

$$[H^+] = \frac{10$$^{-14}$$}{10$$^{-3}$$} = 10$$^{-11}$$\ \mathrm{M}$$

Question 15

Which of the following is a correct statement about the flow of energy and cycling of matter in ecosystems?

Accepted Answer

Energy flows through ecosystems and is eventually lost as heat, while matter cycles between organisms and the environment.

Question 16

Which of the following best describes the difference between a population and a community?

Accepted Answer

A population consists of individuals of one species in an area, while a community includes populations of different species.

Question 17

Which of the following is a real-world consequence of acid precipitation?

Accepted Answer

Acid precipitation can lower soil and water pH, leach nutrients, and mobilize toxic metals, harming organisms.

Question 18

Which of the following is true about isomers?

Accepted Answer

Isomers have the same molecular formula but different arrangements of atoms.

Question 19

A scientist wants to prepare 250 mL of a 2 M glucose solution. The molar mass of glucose is 180 g/mol. How many grams of glucose are needed?

Accepted Answer

$$	ext{Moles} = 2\ \mathrm{M} 	imes 0.25\ \mathrm{L} = 0.5\ \mathrm{mol}$$; $$	ext{Grams} = 0.5\ \mathrm{mol} 	imes 180\ \mathrm{g/mol} = 90\ \mathrm{g}$$

Question 20

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

Accepted Answer

ATP hydrolysis releases free energy that can be coupled to drive cellular work.

General Biology I: Chapters 1–3 Condensed Study Guide

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드