Biology Test I - Macromolecules

Front 1

What are macromolecules?

Back 1

- large organic polymers formed from monomers

Front 2

By what process are macromolecules formed?

Back 2

Polymerisation
(dehydration, condensation)
- involves loss of water

Front 3

Macromolecules are broken down by:

Back 3

addition of water (hydrolysis)

Front 4

What are the 4 classes of macromolecules?

Back 4

1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids

Front 5

Carbohydrates (define)

Back 5

- sugars and their polymers

Front 6

What do carbohydrates serve as?

Back 6

smallest carbohydrates serve as fuel and carbon sources

Front 7

What are the monomers of carbohydrates?

Back 7

monosaccharides

Front 8

Monosaccharides (properties)

Back 8

1. Major nutrients for cells (glucose being most common)
2. Can be produced by photosynthetic organisms
3. Stores energy in their chemical bonds (used by cellular respiration -> ATP)
4. Carbon backbone three to seven
5. Structure
6. Can exist in chain or ring
7. Glucose rings have two forms : alpha vs beta

Front 9

Carbon backbone three to seven (monosaccharides)

Back 9

3 carbons: triose
5 carbons: pentose (DNA and RNA)
6 carbons: hexose (glucose)

Front 10

Structure of a monosaccharide

Back 10

- 1 carbon double bonded to an oxygen (C=O) [carbonyl group]
- Other carbons attached to hydroxyl group (OH) [H-C-OH]

Front 11

Monosaccharide rings (examples)

Back 11

glucose, galacose, fructose

Front 12

Glucose in ring form (alpha vs beta)

Back 12

Alpha-glucose: OH on carbon 1 is below ring
Beta-glucose: OH on carbon 1 is above ring

Front 13

Disaccharides (define)

Back 13

- consists of two monosaccharides joined by a glycosidic linkage

Front 14

Glycosidic linkage (define)

Back 14

covalent bond formed by a condensation reaction

Front 15

Examples of disaccharides

Back 15

maltose: glucose-glucose (beer/wine)
lactose: galactose-glucose (milk)
sucrose: glucose-fructose (sugar)

Front 16

Polysaccharides (define)

Back 16

few hundread to tens of thousands of monosaccharides linked together

Front 17

What are polysaccharides for?

Back 17

Energy storage & structural support

Front 18

Types of polysaccharides

Back 18

1. Energy storage (alpha-glucose)
2. Structural (beta-glucose)

Front 19

Energy storage polysaccharides (in plants)

Back 19

Starch:
- glucose monomers in the alpha-configuration
- unbranched
- forms a helix (spiral)
- found in wheat, corn, and potatoes
- most animals have digestive enzymes that can hydrolyse starch

Front 20

Energy storage polysaccharides (in animals)

Back 20

glycogen:
- large highly branched glucose polymer
- stored in human liver and muscle cells

Front 21

Structural polysaccharides in plants

Back 21

Cellulose:
- linear unbranched polymer of glucose in beta configuration
- reinforces plant cell walls
- cannot be digested by animals (lack the enzyme to break down beta-glycosidic linkages)

Front 22

Structural polysaccharides in insects and crustaceans

Back 22

chitin:
- polymer comprised of beta-glucose monomers substituted on carbon 2 with an amino group
- building blocks of the cell wall of Fungi
- exoskeleton of arthropods

Front 23

Lipids (characteristics)

Back 23

- not polymers
- insoluble in water; hydrophobic

Front 24

Types of lipids

Back 24

1. Fats (storage)
2. Phospholipids (major component of cell membranes)
3. Steroids: cholesterol, hormones

Front 25

Fats (define)

Back 25

Constructed from glycerol and fatty acids

Front 26

Glycerol

Back 26

a three carbon alcohol

Front 27

Fatty acids

Back 27

long hydrocarbon (16-18 carbons)
carboxyl group at one end
hydrophobic due to hydrocarbon chain

see notes

Front 28

Fats can be either:

Back 28

saturated or unsaturated

Front 29

Saturated fatty acid

Back 29

no carbon-carbon double bonds
hydrogen at every possible position
straight chains
solid at room temperature (butter)

Front 30

Unsaturated fatty acid

Back 30

Contains a C=C double bond
causes a "kink" in the hydrocarbon backbone
liquid at room temperature (vegetable oil)

Front 31

Formation of fats

Back 31

Condensation reaction
formation of ester linkage
- 3 fatty acids link to one glycerol
(triglycerides)

Front 32

Function of fats

Back 32

1. Storage of energy (twice as much energy as polysaccharide)
2, Protects internal organs
3. Prevents heat loss (whales and seals)

Front 33

Phospholipids (structure)

Back 33

1 glycerol molecule
2 fatty acids molecules
1 phosphate group (PO4-)
1 hydrophilic group attached to phosphate group

Front 34

Phospholipids (properties)

Back 34

hydrophobic and hydrophilic (amphipathic)
- fatty acid chains -> hydrophobic
- phosphate group -> hydrophilic

Front 35

In water, phospholipids form:

Back 35

aggregates, micelles
- hydrophilic head outward, contact with water
- hydrophobic chains pointing towards the center, shielding from water

Front 36

In cell membranes, phospholipids form:

Back 36

lipid bilayer
- hydrophilic out
- hydrophobic tails face each other
forms barriers between:
- intracellular and extracellular water

Front 37

Steroids (structure)

Back 37

carbon skeleton consisting of four fused carbon rings

Front 38

Cholesterol (characteristics)

Back 38

part of cell membranes
- starting compound for other steroids

Front 39

Proteins (functions)

Back 39

1. Structural support
2. Transport
3. Hormonal
4. Movement
5. Defensive
6. Enzymatic
THE MDS

Front 40

Protein (monomer)

Back 40

amino acids

Front 41

Polymers of amino acids are called:

Back 41

polypeptides

Front 42

Number of different amino acids

Back 42

20

Front 43

Protein is composed of:

Back 43

one or more polypeptides

Front 44

Amino acids (structure)

Back 44

Four components attached to a central carbon
1. Hydrogen
2. Carboxyl group
3. Amino group
4. R-group of side chain
see notes

Front 45

Formation of polypeptides

Back 45

forms between two amino acids
- condensation reaction (carboxyl group OH binds with H of NH2 to form water)

Front 46

Linkage between amino acids

Back 46

Peptide bond
- covalent
- few amino acids to thousands

Front 47

Protein structure

Back 47

3D structure of 4 levels
1. Primary structure
2. Secondary
3. Tertiary
4. Quaternary

Front 48

Primary structure of proteins

Back 48

Linear sequence of amino acids

Front 49

Secondary structure of proteins

Back 49

1. alpha-helix (corkscrew to get into cell membranes)
2. beta-pleated sheets (confers strength) [H-bonds between parts of parallel polypeptide proteins]

Front 50

Tertiary structure of proteins

Back 50

irregular folds, bends, and contortions

Front 51

Quaternary structure of proteins

Back 51

Complex of more than one polypeptide
e.g. Hemoglobin (four polypeptides)

Front 52

Nucleic acids (function)

Back 52

Stores and transmits hereditary information

Front 53

Genes dictate:

Back 53

amino acid sequence in proteins

Front 54

Gene = ?

Back 54

sequence of DNA
- sequence of nucleotides

Front 55

DNA is passed from generation to...

Back 55

generation

Front 56

What are the types of nucleic acids?

Back 56

A. Deoxyribonucleic acid, DNA
B. Ribonucleic acid, RNA

Front 57

Deoxyribonucleic acid (characteristics)

Back 57

- chromosomes are comprised of DNA (contains hundred to thousands of genes)
- not directly involved in protein synthesis
- directs its own replication

Front 58

Nucleic acids (structure)

Back 58

- polymers of monomers, nucleotides

Front 59

Nucleotides comprised of:

Back 59

1. Nitrogen containing base
2. Pentose sugar
3. Phosphate

Front 60

Nitrogen containing base (types)

Back 60

1. Pyrimidines
2. Purines

Front 61

Pyrimidines (define)

Back 61

- 6 membered ring of carbon and nitrogen
DNA: Cytosine and Thymine
RNA: Cytosine and Uracil
CUT PY

Front 62

Purines (define)

Back 62

- 5 membered ring fused to a 6 membered ring of carbon and nitrogen
DNA: Adenine and Guanine

Front 63

Sequence of nitrogen bases

Back 63

no specific sequence, each gene is unique

Front 64

Pentose sugar in nucleic acids

Back 64

RNA: Ribose (H-C-OH on carbon 2)
DNA: Deoxyribose (lacks an oxygen atom at carbon 2 - H-C-H)

Front 65

Phosphate in nucleic acids

Back 65

Attached to carbon 5 of sugar

Front 66

Synthesis of nucleic acid

Back 66

Connects sugar of one nucleotide to the phosphate of another nucleotide

Front 67

Linkage between nucleic acids

Back 67

Phosphodiester bond

Front 68

Backbone of nucleic acids

Back 68

sugar + phosphate backbone

Front 69

Structure of RNA

Back 69

single-stranded

Front 70

Structure of DNA

Back 70

double-stranded
- double helix (Watson and Crick)
- Sugar phosphate backbone outside helix
- bases inside helix
- strands held together by H-bonds

Front 71

Base pairing rules (DNA)

Back 71

A-T: 2 H-bonds
G-C: 3 H-bonds

Front 72

Strands of DNA are :

Back 72

- complementary
G-C vs A-T
during replication, each strand works as a template
- anti-parallels