chapter 2 (The Chemistry of Living Things)

Question 1

What do living organisms primarily depend on for survival?

Answer 1

Chemical reactions

Life relies on various chemical processes to sustain biological functions.

Question 2

What are the three most abundant elements in living organisms?

Answer 2

Carbon, Hydrogen, Oxygen

These elements are fundamental to the structure of biomolecules.

Question 3

What is the smallest unit of an element?

Answer 3

Atom

Atoms are the building blocks of matter.

Question 4

List the elements essential to life.

Answer 4

• Carbon (C)
• Hydrogen (H)
• Oxygen (O)
• Nitrogen (N)
• Phosphorus (P)
• Sulfur (S)

These elements form the basis of biological molecules.

Question 5

What type of bond involves the attraction between oppositely charged ions?

Answer 5

Ionic bond

Example: Na⁺ + Cl⁻ = NaCl.

Question 6

What is a covalent bond?

Answer 6

Atoms share electrons

Covalent bonding can be nonpolar or polar.

Question 7

Define nonpolar covalent bonds.

Answer 7

Equal sharing of electrons

Example: H₂.

Question 8

Define polar covalent bonds.

Answer 8

Unequal sharing of electrons, creating partial charges

Example: Water.

Question 9

What are hydrogen bonds?

Answer 9

Weak bonds between polar molecules

Important for water structure and stabilizing DNA/proteins.

Question 10

What is the role of water in biological systems?

Answer 10

Universal solvent and essential for biochemical reactions

Water’s polarity contributes to its solvent properties.

Question 11

What is condensation (dehydration synthesis)?

Answer 11

Links monomers to form polymers + water

This reaction is crucial in forming biomolecules.

Question 12

What is hydrolysis?

Answer 12

Breaks polymers into monomers using water

It is the reverse process of dehydration synthesis.

Question 13

What is the function of enzymes?

Answer 13

Speed up chemical reactions

Enzymes lower the activation energy required for reactions.

Question 14

What are carbohydrates?

Answer 14

Sugars and starches that provide energy

They are classified into monomers (monosaccharides) and polymers (polysaccharides).

Question 15

What is the monomer of carbohydrates?

Answer 15

Monosaccharides

Example: Glucose.

Question 16

What is the polymer of carbohydrates?

Answer 16

Polysaccharides

Examples: Starch, glycogen, cellulose.

Question 17

What are lipids?

Answer 17

Fats, oils, and phospholipids

They function in energy storage, insulation, and forming cell membranes.

Question 18

What is the function of phospholipids?

Answer 18

Form cell membranes

Their structure allows them to create bilayers in aqueous environments.

Question 19

What are proteins made of?

Answer 19

Amino acids

Proteins perform a variety of functions in biological systems.

Question 20

List the functions of proteins.

Answer 20

• Enzymes
• Structural support
• Hormones
• Transport
• Immunity

Proteins are versatile and essential to many cellular processes.

Question 21

What are nucleic acids?

Answer 21

DNA and RNA

They are responsible for storing and transmitting genetic information.

Question 22

What are acids?

Answer 22

Substances that release H⁺ ions

Example: HCl.

Question 23

What are bases?

Answer 23

Substances that accept H⁺ or release OH⁻

Example: NaOH.

Question 24

What are salts?

Answer 24

Ionic compounds formed when acids react with bases

Example: NaCl.

Question 25

What role do buffers play?

Answer 25

Help maintain pH balance ## Footnote Buffers resist changes in pH in biological systems.

Question 26

What are functional groups?

Answer 26

Clusters of atoms that influence molecule behavior ## Footnote They determine the chemical properties of organic molecules.

Question 27

List examples of functional groups.

Answer 27

* Hydroxyl (-OH) * Carboxyl (-COOH) * Amino (-NH₂) * Phosphate (-PO₄) ## Footnote These groups are critical in the formation and function of biomolecules.

Question 28

What is unique about carbon's bonding capabilities?

Answer 28

Can form 4 covalent bonds ## Footnote This allows for diverse molecular structures including chains, rings, and branches.

Question 29

What are key terms to understand in this chapter?

Answer 29

* Atom * Molecule * Polymer * Enzyme * Acid/Base ## Footnote Familiarity with these terms is crucial for mastering the content.

Question 30

Fill in the blank: _______ vs. ionic bonds.

Answer 30

Covalent ## Footnote Understanding the differences between these bond types is fundamental in chemistry.

Question 31

Fill in the blank: _______ vs. hydrolysis.

Answer 31

Dehydration ## Footnote These processes are opposites in building and breaking down biomolecules.

Question 32

What are the four types of biomolecules?

Answer 32

* Carbohydrates * Lipids * Proteins * Nucleic Acids ## Footnote Each type has distinct structures and functions in living organisms.

Question 33

What roles do proteins play?

Answer 33

Enzymes, structural support, hormones, transport, immunity ## Footnote Proteins are essential for numerous cellular functions and processes.