Chapter 3

Question 1

Macromolecule

Answer 1

A very large molecule built from smaller repeating units (monomers). the four main classes in biology are carbohydrate, lipids, nucleic acids, and proteins

Question 2

Polymer

Answer 2

A long molecule consisting of many similar or identical monomers linked together by covalent bonds

Question 3

monomer

Answer 3

a small molecule that serves as the building block of a polymer

Question 4

Dehydration reaction

Answer 4

A chemical reaction in which two molecules are joined together by removal of a water molecule, often forming a covalent bond in the process (synthesis of polymers)

Question 5

Hydrolysis Reaction

Answer 5

A chemical reaction in which a molecule is split into two smaller molecules by addition of a water molecule, breaking a covalent bond (breakdown of polymers)

Question 6

Carbohydrate

Answer 6

A class of macromolecules that includes sugars and sugar polymers, serving as a source of energy, a source of carbon, and structural components

Question 7

Monosaccharides

Answer 7

A simple sugar, the monomer f carbohydrates, containing one carbonyl group and multiple hydroxyl groups.

Question 8

Disaccharides

Answer 8

A sugar molecule consisting of two monosaccharides joined by a glycosidic linkage.

Question 9

Polysaccharides

Answer 9

A carbohydrate polymer consisting of many monosaccharides joined together by glycosidic linkages

Question 10

Glycosidic bonds (linkages)

Answer 10

A covalent bond that join two carbohydrate mo0lecules (monosaccharides or larger units). Formed by a dehydration reaction

Question 11

Starch

Answer 11

A storage polysaccharide found in plants, composed of glucose monomers linked by a-1,4-glycosidic bonds (and a-1,6 at branch points)

Question 12

Cellulose

Answer 12

A structural polysaccharide found in plant cell walls, a linear, un branched polymer of glucose linked by B-1,4-glycosidic linkages

Question 13

glycogen

Answer 13

A storage polysaccharide found in animal liver and muscle cells, a highly branched polymer of glucose by a-1,4- and a-1,6-glycosidic bonds

Question 14

Lipid

Answer 14

A diverse group of hydrophobic macromolecules, including fats, phospholipids, and steroids. They are not true polymers and are characterized by their insolubility in water

Question 15

Fat (triacylglycerol)

Answer 15

A lipid composed of one glycerol molecule and three fatty acid molecules joined by ester linkages. Functions in energy storage, insulation, and protection.

Question 16

Glycerol

Answer 16

A three-carbon alcohol with a hydroxyl group attached to each carbon, a component of fats and phospholipids

Question 17

Fatty acids

Answer 17

A long hydrocarbon chain with a carboxyl group at one end, a component of fats and phospholipids

Question 18

Ester linkage

Answer 18

The covalent bond that connect the glycerol molecule to the fatty acids in a fat. Formed by a dehydration reaction

Question 19

Phospholipid

Answer 19

A li[id composed of a glycerol molecule, two fatty acids, and phosphate group. The main structural component of cell membranes, exhibiting amphipathic properties

Question 20

Amphipathic

Answer 20

Having both hydrophilic (water-loving) and hydrophobic (water-fearing) parts

Question 21

Steroid (sterol)

Answer 21

A type of lipid characterized by a carbon skeleton consisting of four fused rings

Question 22

Saturated fatty acid

Answer 22

A fatty acid in which carbon atoms in the hydrocarbon chain are connected by single bonds, resulting in a straight molecule

Question 23

Unsaturated fatty acid

Answer 23

A fatty acid containing one or more carbon-carbon double bonds in its hydrocarbon chain, resulting in a bent molecule

Question 24

Cis fatty acid

Answer 24

An unsaturated fatty acid where the hydrogen atoms adjacent to the double bond are on the same side, creating a ben in the chain. Most naturally occurring

Question 25

Trans fatty acids

Answer 25

An unsaturated fatty acid where the hydrogen atoms adjacent to the double bonds are on opposite sides, resulting in a more linear chain similar to a saturated fatty acid. Often produced artificially through hydrogenation.

Question 26

Nucleotide

Answer 26

The monomer unit of nucleic acids, consisting of a nitrogenous base, a five-carbon sugar (ribose or deoxyribose), and one or more phosphate groups

Question 27

Ribonucleotide

Answer 27

A nucleotide containing ribose as its five-carbon sugar; found in RNA

Question 28

Deoxyribonucleotide

Answer 28

A nucleotide containing deoxyribose as its five-carbon sugar; found in DNA

Question 29

Nitrogenous base

Answer 29

A molecule containing nitrogen and having chemical properties of a base. in nucleic acids, these include adenine (A), guanine (G), cytosine(C) thymine (T) (IN DNA), and uracil (U) (In RNA)

Question 30

Phosphodiester bond

Answer 30

A covalent bond that links sugar of one nucleotide to the phosphate group of the next in a nucleic acid chain

Question 31

Directionality (of nucleic acids)

Answer 31

The inherent polarity of a nucleic acid strand due to the asymmetric nature of the sugar-phosphate backbone, resulting in a distinct 5' end (with a phosphate group) and a 3' end (with a hydroxyl group)

Question 32

DNA double helix

Answer 32

The three-dimensional structure of DNA, consisting of two antiparallel strands wound around each other, with the sugar-phosphate backbones on the outside and the nitrogenous bases paired in the interior viz hydrogen bonds

Question 33

Base-pairing

Answer 33

The specific hydrogen bonding interactions between nitrogenous bases in nucleic acids: adenine (A) with thymine (T) (in DNA) or uracil (U) (in RNA), and guanine (G) with cytosine (C)

Question 34

Antiparallel

Answer 34

The orientation of the two strands in a DNA double helix, where one strand runs in the 5' to 3' direction and the other runs in the 3' to 5' direction

Question 35

RNA strand

Answer 35

A single-stranded nucleic acid molecule that plays various roles in the cell, including carrying genetic information and participating in protein synthesis

Question 36

Protein

Answer 36

A functional biological molecule composed of one or more polypeptides folded into a specific three-dimensional structure

Question 37

Amino acid

Answer 37

A monomer unit of proteins, consisting of a central alpha (a) carbon atom bonded to an amino group, a carboxyl group, a hydrogen group, and a unique side chain (R group)

Question 38

peptide bond

Answer 38

A covalent bond that links the carboxyl group of one amino acid to the amino group of another, formed by a dehydration reaction

Question 39

Directionality (of polypeptides)

Answer 39

The inherent polarity of a polypeptide chain due to the presence of a free amino group at one end (N-terminus) and free carboxyl group at the other end (C-terminus)

Question 40

Polypeptide

Answer 40

linear chain of amino acids linked together by peptide bonds

Question 41

Primary structure (of protein)

Answer 41

The linear sequence of amino acids in a polypeptide chain, determined by the genetic code

Question 42

Secondary Structure (of protein)

Answer 42

Localized, repetitive folding patterns within a polypeptide chain, such as the alpha (a) helix and beta (B) sheet, stabilized by hydrogen bonds between backbone atoms

Question 43

Tertiary structure (or protein)

Answer 43

The overall three-dimensional shape of a single polypeptide chain, resulting from interaction between the side chain (R groups) of amino acids. These interaction include hydrogen bonds, ionic bond, hydrophobic interactions, and disulfide bonds

Question 44

Conservative Change (amino acid substitution)

Answer 44

The replacement if one amino acid with another that has similar chemical properties

Question 45

Non-conservative change (amino acid substitution)

Answer 45

The replacement of one amino acid with another that has significantly different chemical properties

Question 46

Denature (of protein)

Answer 46

The process by which a protein loses its native three dimensional structure due to the disruption of non-covalent bonds and interactions. This typically leads to a loss of function

Question 47

Degradation (protein)

Answer 47

The breakdown of a protein into smaller peptide or individual amino acids, involving the breaking of peptide bonds (the covalent bonds of primary structure)