Q: A solution has a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$this solution?

$$[H^+] = 1 \times 10$$^{-4}$$ M

Question 1

Which of the following statements best explains why water is considered a 'versatile solvent' in biological systems?

Accepted Answer

Water's polarity allows it to dissolve many ionic and polar substances by surrounding and separating their ions or molecules.

Question 2

A scientist is studying a molecule with the formula $$C_{6}H$$_{12}$$O_{6}$. Which class of organic molecules does this compound belong to?

Accepted Answer

Monosaccharides

Question 3

Which property of water allows certain insects, such as water striders, to walk on the surface of water without sinking?

Accepted Answer

Cohesive forces leading to surface tension

Question 4

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed when one atom donates one or more electrons to another atom, resulting in oppositely charged ions that attract each other.

Question 5

A solution has a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$this solution?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-4}$$ M

Question 6

Which of the following is a correct statement about proteins?

Accepted Answer

Proteins are polymers of amino acids joined by peptide bonds.

Question 7

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Hydrogen bonds in ice create a lattice structure that makes ice less dense than liquid water.

Question 8

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

Accepted Answer

Catalyzing chemical reactions

Question 9

A biologist discovers a molecule that contains carbon, hydrogen, oxygen, and nitrogen, and is composed of a central carbon atom bonded to an amino group ($$-NH_2$), a carboxyl group (-$$COOH$$), a hydrogen atom, and a variable R group. This molecule is most likely:

Accepted Answer

An amino acid

Question 10

Which of the following statements about acids and bases is correct?

Accepted Answer

Acids increase the concentration of hydrogen ions ($$H^+) in $$solution.

Question 11

Which of the following best describes a polysaccharide?

Accepted Answer

A polymer made up of many repeated units of monosaccharides.

Question 12

Which of the following is a trace element required by living organisms in very small quantities?

Accepted Answer

Iodine (I)

Question 13

A student mixes two amino acids together and a water molecule is released in the process. What type of reaction has occurred?

Accepted Answer

Dehydration synthesis (condensation)

Question 14

Which of the following best explains why cellulose is important in plant cells?

Accepted Answer

It acts as a major structural component of the cell wall.

Question 15

Which of the following statements about nucleic acids is correct?

Accepted Answer

Nucleic acids store and transmit genetic information.

Question 16

A solution has a pH of 9. Which of the following best describes this solution?

Accepted Answer

It is basic (alkaline).

Question 17

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

Accepted Answer

Starch is the main storage polysaccharide in plants, while glycogen is the main storage polysaccharide in animals.

Question 18

Which of the following best describes the relationship between cohesion and adhesion in water transport in plants?

Accepted Answer

Cohesion and adhesion work together to allow water to move upward through plant vessels against gravity.

Question 19

Which of the following is true about the pH scale?

Accepted Answer

A decrease of one unit on the pH scale represents a tenfold increase in hydrogen ion concentration.

Unit 1: Chemistry of Life – General Biology Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard