Chapter 2 – Chemistry of Life

Question-and-answer flashcards covering atoms, ions, bonding, macromolecules, and their functions from Chapter 2: Chemistry of Life.

What is the correct hierarchy of life from smallest to largest?

Atom < Molecule < Macromolecule < Cell < Tissue < Organ < Organ System < Organism

What is an atom?

The smallest unit of a chemical element.

What charge and location does a proton have?

Positive charge; located in the nucleus.

What are the charge and location of a neutron?

No charge (neutral); located in the nucleus.

What are the charge and location of an electron?

Negative charge; orbits the nucleus.

Which element typically has no neutrons?

Hydrogen.

What does the atomic number represent?

The number of protons (and, in a neutral atom, the number of electrons).

How is atomic mass calculated?

Number of protons plus number of neutrons.

How do you determine the number of neutrons in an atom?

Round the atomic mass and subtract the atomic number.

What is an ion?

An atom with unequal numbers of protons and electrons.

What is an anion?

An ion that gains electrons and becomes negatively charged.

What is a cation, and what memory tip helps you remember it?

An ion that loses electrons and becomes positively charged; the “T” in caTion looks like a + sign.

Which chemical bond forms through electron transfer between atoms?

Ionic bond.

Why are ionic bonds strong?

Because oppositely charged ions (cation and anion) strongly attract each other.

What is a covalent bond?

A bond formed by sharing electrons between atoms.

What is the difference between non-polar and polar covalent bonds?

Non-polar covalent bonds share electrons equally; polar covalent bonds share electrons unequally, creating slight charges on the molecule’s ends.

What is a hydrogen bond?

A weak attraction between polar molecules due to partial positive and negative charges.

What is the monomer of carbohydrates?

Monosaccharide (e.g., glucose, fructose, galactose).

What is the primary function of carbohydrates?

Short-term energy supply.

What elemental ratio characterizes carbohydrates?

C:H:O in a 1:2:1 ratio (e.g., C6H12O6).

What is a monosaccharide?

A single-sugar molecule such as glucose.

What is a disaccharide, and give an example?

Two-sugar molecule; example: sucrose (glucose + fructose).

What is a polysaccharide?

A complex carbohydrate composed of many sugars, such as starch, cellulose, or glycogen.

Which polysaccharide stores energy in plants?

Starch.

Which polysaccharide provides structural support in plants and serves as dietary fiber?

Cellulose.

Which polysaccharide stores energy in animals?

Glycogen (in muscle and liver).

What common trait do all lipids share?

They are insoluble in water.

What are the components and primary functions of a triglyceride?

Glycerol + 3 fatty acids; functions in energy storage, insulation, and cushioning.

What are the components of a phospholipid, and what is its main role?

Glycerol + 2 fatty acids + phosphate group; forms the main component of cell membranes.

What is the monomer of proteins?

Amino acid.

Name the four basic parts of an amino acid.

Amino group, carboxyl group, hydrogen atom, and variable R group.

List three major functions of proteins.

Structural support (e.g., collagen), catalyzing reactions (enzymes), and cell signaling.

What is the monomer of nucleic acids?

Nucleotide (phosphate group + sugar + nitrogenous base).

What sugar and bases are found in DNA?

Deoxyribose sugar; bases A, T, G, C.

What sugar and bases are found in RNA?

Ribose sugar; bases A, U, G, C.

What are the primary functions of DNA and RNA?

DNA: genetic blueprint; RNA: carries instructions for protein synthesis.