Concept explainers
Polar molecules
a. dissolve in lipids.
b. are hydrophobic.
c. form covalent bonds.
d. form ionic bonds.
Introduction:
Molecules can be broadly classified as polar or nonpolar. Polar molecules have an unequal distribution of electrons in their outermost orbitals giving a positive charge to one end of the molecule and negative charge to the other end. This unequal distribution of charges is responsible for the unique properties of polar molecules.
Answer to Problem 1MC
Correct answer:
Polar molecules form ionic bonds.
Explanation of Solution
Explanation for the correct answer:
Ionic bonds are formed by electrostatic interactions between oppositely charged ions. The atoms, which have gained extra electrons, are negatively charged (anions) and the atoms, which have lost electrons, are positively charged (cations). Such atoms can combine together by an ionic bond and form polar molecules. Option (d) is given that polar molecules form ionic bonds. Hence, option (d) is correct.
Explanation for incorrect answers:
Option (a) is given that polar molecules dissolve in lipids. Polar molecules are attracted to other polar molecules. Water is a polar molecule which makes all polar molecules water soluble. Oil is a nonpolar molecule that makes all nonpolar molecules lipid soluble. So, it is an incorrect answer.
Option (b) is given that polar molecules are hydrophobic. Polar molecules can dissolve in water which means that they are hydrophilic or ‘water-loving.’ So, it is an incorrect option.
Option (c) is given that polar molecules form covalent bonds. Covalent bonds are formed by the sharing of electron pairs between the atoms. This sharing of electrons gives the molecule a stable bond in which the attractive and repulsive forces are balanced. So, this is an incorrect option.
Hence options (a), (b), and (c) are incorrect.
Therefore, polar molecules are formed by ionic bonds between a cation and an anion. They are hydrophilic or water-soluble in nature.
Want to see more full solutions like this?
Chapter 3 Solutions
Biology: Life on Earth (11th Edition)
- Which type of bond represents a weak chemical bond? a. hydrogen bond b. ionic bond c. covalent bond d. polar covalent bondarrow_forwardThe mutual attraction of opposite charges holds atoms together as molecules in an _______ bond. a. ionic c. polar covalent b. hydrogen d. nonpolar covalentarrow_forwardFatty acids in phospholipids and triacylglycerols interact with one another by (a) disulfide bridges (b) van der Waals interactions (c) covalent bonds (d) hydrogen bonds (e) fatty acids do not interact with one anotherarrow_forward
- The monomers that make up proteins are called_____. a. nucleotides b. disaccharides c. amino acids d. chaperonesarrow_forwardAtoms share electrons unequally in an _______ bond. a. ionic c. polar covalent b. hydrogen d. nonpolar covalentarrow_forwardthe primary structure of proteins is held together by a. covalent bonds b. hydrogen bonds c. disulfide bonds d. ionic bondsarrow_forward
- Which of the following statements about chemicalbonds is true?a. Covalent bonds are stronger than ionic bonds.b. Hydrogen bonds occur between two atoms ofhydrogen.c. Bonding readily occurs between nonpolar andpolar molecules.d. A molecule of water is unlikely to bond with anion.arrow_forwardPeptide bonds occur in which type of biochemical compounds? a) lipids b) carbohydrates c) proteins d) nucleic acidsarrow_forwardFats do not dissolve in water because Select one: a. There are no C-H bonds to form hydrogen bonds with water b. There are no O-H bonds form hydrogen bonds with water c. There are no C-C bonds to form hydrogen bonds with water d. There are no C-H bonds for covalent bonds with water e. There are no C-C bonds to form covalent bonds with waterarrow_forward
- Which type of interaction commonly persists even after urea is added to proteins for denaturation? a) Disulfide bonds b) Ionic interactions c) Hydrophobic interactions d) Hydrogen bondsarrow_forwardWhich of the following is not associated with proteins? a.) amino acids b.) hydrogenation c.) peptide bonds d) bending and foldingarrow_forwardWhich of the following statements is incorrect about disulfide bonds? a. They form between two cysteine amino acids.b. They are noncovalent.c. They contribute to the tertiary structure of some proteins.d. They contribute to the quaternary structure of some proteins.e. They involve the loss of two hydrogen atoms.arrow_forward
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax CollegeBiology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning
- Human Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning