Week 1 - Cells, Atoms, & Molecules

Question 1

Electronegativity

Answer 1

The ability of an atom to attract electrons in a covalent bond.

Question 2

Valence Electrons

Answer 2

The electrons in the outermost shell of an atom; involved in bonding.

Question 3

Isotope

Answer 3

Atoms of the same element with different numbers of neutrons (same protons, different mass).

Question 4

Non Polar Covalent Bonds

Answer 4

A bond where electrons are shared equally between atoms (usually between similar electronegativities).

Question 5

Polar Covalent Bonds

Answer 5

A bond where electrons are shared unequally, causing partial charges on atoms.

Question 6

Ionic Bonds

Answer 6

Bonds formed when one atom donates an electron to another, creating oppositely charged ions that attract.

Question 7

Hydrophilic

Answer 7

“Water-loving”; substances that dissolve easily in water (usually polar or charged).

Question 8

Hydrophobic

Answer 8

“Water-fearing”; substances that do not dissolve in water (nonpolar).

Question 9

Amphiphilic

Answer 9

Molecules that have both hydrophilic and hydrophobic parts (e.g., phospholipids).

Question 10

Hydrogen Bonds

Answer 10

Weak attractions between a hydrogen atom (bonded to N, O, or F) and another electronegative atom.

Question 11

Van der Waals Interaction

Answer 11

Weak, temporary attractions due to momentary shifts in electron density in molecules.

Question 12

Macromolecules

Answer 12

Large, complex molecules (like proteins, nucleic acids, carbohydrates, and lipids).

Question 13

Depolymerization

Answer 13

The breakdown of polymers into monomers (e.g., via hydrolysis).

Question 14

Polymerization/Polymers

Answer 14

The formation of large molecules (polymers) by linking monomers (repeating units).

Question 15

Carbohydrates

Answer 15

Sugars and their polymers; used for energy and structure.

Question 16

Monosaccharide

Answer 16

A single sugar molecule (e.g., glucose).

Question 17

Polysaccharide

Answer 17

A polymer of many monosaccharides (e.g., starch, glycogen).

Question 18

Cellulose

Answer 18

A structural polysaccharide found in plant cell walls; made of glucose but indigestible by humans.

Question 19

Glycosidic Bond

Answer 19

The covalent bond formed between two monosaccharides.

Question 20

Proteins

Answer 20

Polymers of amino acids; serve structural, enzymatic, and regulatory roles.

Question 21

Nucleic Acids

Answer 21

DNA and RNA; polymers of nucleotides that store and transmit genetic information.

Question 22

Polynucleotide

Answer 22

A polymer of nucleotides (i.e., a strand of DNA or RNA).

Question 23

Steroids

Answer 23

Lipids with a four-ring carbon structure (e.g., cholesterol).

Question 24

Glycerol

Answer 24

A 3-carbon molecule that forms the backbone of fats and phospholipids.

Question 25

Lipids

Answer 25

Hydrophobic molecules including fats, oils, steroids, and phospholipids.

Question 26

Triacylglycerol (Triglyceride)

Answer 26

A fat made of one glycerol and three fatty acids.

Question 27

Phospholipid

Answer 27

A lipid with a phosphate group and two fatty acids; key component of cell membranes.

Question 28

Saturated FA

Answer 28

Fatty acids with no double bonds; solid at room temp.

Question 29

Unsaturated FA

Answer 29

Fatty acids with one or more double bonds; usually liquid at room temp.

Question 30

Cis Bonds

Answer 30

Hydrogen atoms on the same side of the double bond; creates a bend.

Question 31

Trans Bonds

Answer 31

Hydrogen atoms on opposite sides; straighter chain.

Question 32

Cis Melting/Boiling Point

Answer 32

Cis fats have lower melting points (because of the kink, they pack less tightly).

Question 33

Trans Melting/Boiling Point

Answer 33

Trans fats have higher melting points (they pack more like saturated fats).

Question 34

Prokaryote

Answer 34

A cell without a nucleus (e.g., bacteria, archaea).

Question 35

Cations

Answer 35

Positively charged ions (e.g., Na⁺).

Question 36

Anions

Answer 36

Negatively charged ions (e.g., Cl⁻).

Question 37

Dehydration

Answer 37

A chemical reaction that joins monomers by removing water (also called condensation reaction).