Q: Which equation correctly represents the relationship between pH and hydrogen ion concentration $$[H^+]$$?

$$\text{pH} = -\log_{10} [H^+]$$

Q: A buffer system in blood helps maintain pH homeostasis. If excess acid is added to the blood, which reaction will occur to minimize pH change? $$\text{HCO}_3^- + \text{H}^+ \rightarrow \text{H}_2\text{CO}_3$$

The reaction shifts to produce more $$\text{H}_2\text{CO}_3$$, removing $$\text{H}^+$$ from solution.

Question 1

Which subatomic particle is primarily responsible for the chemical properties of an atom, and why?

Accepted Answer

Electrons, because their arrangement in shells determines how atoms bond and interact.

Question 2

Which of the following best describes a hydrogen bond?

Accepted Answer

A bond formed between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Question 3

Water has a high specific heat capacity. Which property of water is most responsible for this, and what is the biological significance?

Accepted Answer

Its hydrogen bonds; they absorb heat energy, helping organisms maintain stable internal temperatures.

Question 4

Given the following pH values, which solution is the most acidic, and by how much is it more acidic than a solution with pH 7?

$$	ext{Solution A: pH 2}$$ 
$$	ext{Solution B: pH 5}$$ 
$$	ext{Solution C: pH 7}$$ 
$$	ext{Solution D: pH 9}$$

Accepted Answer

Solution A; it is 100,000 times more acidic than pH 7.

Question 5

Which equation correctly represents the relationship between pH and hydrogen ion concentration $$[H^+]$$?

Accepted Answer

$$	ext{pH} = -\log_{10} [H^+]$$

Question 6

A buffer system in blood helps maintain pH homeostasis. If excess acid is added to the blood, which reaction will occur to minimize pH change?

$$	ext{HCO}_3^- + 	ext{H}^+ ightarrow 	ext{H}_2	ext{CO}_3$$

Accepted Answer

The reaction shifts to produce more $$	ext{H}_2	ext{CO}_3$$, removing $$	ext{H}^+$$ from solution.

Question 7

Which of the following is a dehydration synthesis reaction?

Accepted Answer

Forming a disaccharide from two monosaccharides with the removal of water.

Question 8

How does the sequence of amino acids in a protein determine its final function?

Accepted Answer

It determines the protein's primary structure, which directly dictates its folding and active sites.

Question 9

Which of the following best explains why enzymes are sensitive to changes in pH and temperature?

Accepted Answer

Changes in pH and temperature can disrupt hydrogen and ionic bonds, affecting the enzyme's three-dimensional shape and active site.

Question 10

Which of the following is NOT a function of nucleic acids in cells?

Accepted Answer

Providing structural support to cell membranes.

Question 11

A mutation changes the sequence of nucleotides in a gene. Which level of protein structure is directly affected first?

Accepted Answer

Primary structure.

Question 12

Which of the following organic molecules is most likely to be affected by hydrolysis in the digestive tract?

Accepted Answer

Starch.

Question 13

Which of the following statements about the directionality of nucleic acids is correct?

Accepted Answer

Nucleic acids have distinct 5' and 3' ends, which determines the direction of synthesis and function.

Question 14

Which of the following best describes the role of carbon in organic molecules?

Accepted Answer

Carbon can form up to four covalent bonds, allowing for complex and diverse organic molecules.

Question 15

A patient has a genetic mutation that changes the shape of a protein channel in their cell membrane. Which property of proteins is most directly affected?

Accepted Answer

Tertiary structure.

Question 16

Which of the following is a correct example of a hydrolysis reaction?

Accepted Answer

Breaking a polysaccharide into monosaccharides by adding water.

Question 17

Which of the following best explains why water is an excellent solvent for biological molecules?

Accepted Answer

Water's polarity allows it to form hydrogen bonds with polar and charged molecules.

Question 18

Which of the following is true about the four major groups of organic compounds?

Accepted Answer

Carbohydrates, proteins, and nucleic acids are polymers made of monomers.

Question 19

A scientist observes that a protein loses its function when exposed to high heat. Which process is most likely occurring?

Accepted Answer

Denaturation, which disrupts the protein's secondary and tertiary structure.

Essential Concepts in General Biology: Atoms, Molecules, and Biological Macromolecules

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