Unit 1 The Chemistry of Life 8-11%

Question 1

How is water a polar molecule?

Answer 1

Unequal sharing of electrons between oxygen and hydrogen → -O and+H.

Question 2

Hydrogen Bonding

Answer 2

Weak bonds between water molecules and other polar substances → gives water its unique properties.

Question 3

Properties of Water

Answer 3

1. Cohesion: H-bonds between water molecules → Surface tension.
2. Adhesion: H-bonds between water molecules and other polar substances → Capillary action.
3. High heat capacity: requires a lot of energy to change temperature.
4. High heat of vaporization: requires a lot of energy to turn into a gas.
5. Expansion upon freezing: water expands when it freezes → less dense.
6. Universal solvent: dissolves polar and ionic substances.

Question 4

Elements of Life

Answer 4

Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, and Sulfur → CHONPS.

Question 5

The elements of life make-up . . .

Answer 5

Carbohydrates, Lipids, Proteins, and Nucleic Acids.

Question 6

What’s unique about carbon?

Answer 6

It forms four covalent bonds → forms chains, branched structures, and rings.

Question 7

Elements in Carbohydrates

Answer 7

Carbon, Hydrogen, and Oxygen → CHO.

Question 8

Elements in Lipids

Answer 8

Carbon, Hydrogen, and Oxygen → CHO.

Question 9

Elements in Proteins

Answer 9

Carbon, Hydrogen, Oxygen, Nitrogen, and sometimes Sulfur → CHON+S.

Question 10

Elements in Nucleic Acids

Answer 10

Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus → CHONP.

Question 11

What are functional groups?

Answer 11

Groups of atoms with their own characteristics such as polarity and charge.

Question 12

What are common functional groups found in macromolecules?

Answer 12

Carbonyl, Caarboxyl, Hydroxyl, Amino, Methyl, Phosphate, and Sulfhydryl →CCHAMPS.

Question 13

What are isomers?

Answer 13

Molecules with the same chemical formula, but different structures → different functions.

Question 14

What is a monomer?

Answer 14

Smallest unit of macromoecules.

Question 15

What is a polymer?

Answer 15

Long chains of repeating monomers.

Question 16

How do you form a polymer?

Answer 16

Dehydration Synthesis: forms covalent bonds by removing a water molecules.

Question 17

How do you break a polymer?

Answer 17

Hydrolysis: breaks covalent bonds by adding a water molecule.

Question 18

Function of Carbohydrates

Answer 18

Short-term energy and structural support in plants.

Question 19

What is the monomer/polymer of carbohydrates (give examples)?

Answer 19

Monosaccharides (simple sugar like glucose).
Disaccharides: two monosaccharides joined by a glycosidic bond (lactose).
Polysaccharides: long chains of monosaccharides → starch & glycogen for energy storage and cellulose & chitin for structural support.

Question 20

Why can humans digest starch and not cellulose?

Answer 20

Starch has has alpha-glycosidic bonds , while cellulose has beta-glycosidic bonds.

Question 21

Function of Lipids

Answer 21

Energy storage, insulation, cell membrane structure, and signaling molecules (hormones).

Question 22

What is the monomer of lipids?

Answer 22

Doesn’t have a single monomer.

Question 23

What are the three types of lipids?

Answer 23

1. Fats: used for energy storage → made of glycerol and fatty acids.
2. Phospholipids: make the cell membrane → hydrophilic heads and hydrophobic tails.
3. Steroids: cholesterol and hormones → ring structure.

Question 24

What is the difference between saturated and unsaturated fat?

Answer 24

Saturated fats only have single carbon bonds → solid, while unsaturated fats have double carbon bonds → liquid.

Question 25

Function of Proteins

Answer 25

Enzymes, structural support, transport, immune defense, cell communication and regulation, etc.

Question 26

What is the monomer/polymer of proteins?

Answer 26

Amino Acids → form peptide bonds to make a long polypeptide chain.

Question 27

Structure of Amino Acids

Answer 27

Composed of a central carbon atom bonded to a hydrogen, amino group (-NH2), carboxyl group (-COOH), and an R-group.

Question 28

What makes R-groups unique?

Answer 28

It determines the amino acid's chemical properties and how it interacts to form a protein → polar, nonpolar, or charged.

Question 29

Primary Structure

Answer 29

Peptide bonds between amino acids.

Question 30

Secondary Structure

Answer 30

Hydrogen bonds between the amino and carboxyl backbone → alpha helix or beta-sheet.

Question 31

Tertiary Structure

Answer 31

Bonding between between the R-groups → 3D.

Question 32

Quaternary Structure

Answer 32

Made up of multiple polypeptides → Hemoglobin.

Question 33

Why are proteins sensitive in high temperatures or pH levels?

Answer 33

Proteins can denature → loses its shape and function.

Question 34

Function of Nucleic Acids

Answer 34

Transmit and carry genetic information.

Question 35

What is the monomer/polymer of nucleic acids?

Answer 35

Nucleotides → form polynucleotides like DNA and RNA.

Question 36

Structure of a Nuceoltide

Answer 36

5-carbon pentose sugar, phosphate group, and a nitrogenous base.

Question 37

What bonds nucleotides together?

Answer 37

Phosphodiester bonds → occur between the phosphate group and hydroxyl group.

Question 38

What are pyrimidines?

Answer 38

Single-ring nitrogenous bases → Cytosine, Thymin, and Uracil.

Question 39

What are purines?

Answer 39

Double-ring nitrogenous bases → Adenine and Guanine.

Question 40

How many hydrogen bonds form between each pair?

Answer 40

A and T form 2, while C and G form 3 → stronger in harsh enviornments.

Question 41

How is DNA antiparallel?

Answer 41

One strands runs in the 5'-3' direction, while the other runs in th 3'-5" direction → lagging and leading strands.

Question 42

In what direction is DNA synthesized?

Answer 42

5'-3' direction → nucleotides are added to the 3' end.

Question 43

What are differences between DNA and RNA?

Answer 43

1. DNA is doubled-stranded, while RNA is single-stranded. 2. DNA contains Thymine, while RNA contains Uracil. 3. DNA contains deoxyribose sugar (H), while RNA contains ribose (-OH).