Macromolecules

Question 1

What are macromolecules?

Answer 1

Large biological molecules essential for life, including proteins, lipids, carbohydrates, and DNA

Question 2

What are proteins composed of?

Answer 2

Proteins are macromolecules composed of amino acids covalently linked by peptide bonds

Question 3

What are the six roles of proteins in cells?

Answer 3

• Structural components
• Catalysis of reaction
• Transport
• Movement
• Storage
• Signalling
• Gene regulation

Question 4

What determines a protein’s structure?

Answer 4

Amino acid sequence and bonding interactions, including covalent peptide bonds and non-covalent interactions

Question 5

What are the four levels of protein structure?

Answer 5

• Primary
• Secondary
• Tertiary
• Quaternary

Question 6

What is the primary protein structure?

Answer 6

Linear sequence of amino acids

Question 7

What is the secondary protein structure?

Answer 7

Alpha helices and beta sheets

Question 8

What is the tertiary protein structure?

Answer 8

3D folding due to bonding interactions

Question 9

What is the quaternary protein structure?

Answer 9

Association of multiple polypeptides

Question 10

What assists proteins in folding?

Answer 10

Chaperone proteins help proteins fold into their lowest energy conformation

Question 11

What are protein domains?

Answer 11

Independently folded regions within a protein, each with specific functions

Question 12

What are fibrous proteins and what is an example of it?

Answer 12

Extended structural
Keratin

Question 13

What are globular proteins and what is an example of it?

Answer 13

Compact functional
Enzymes

Question 14

How are extracellular proteins stabilised?

Answer 14

By disulfide bonds

Question 15

What is a ligand in protein binding?

Answer 15

A molecule that binds to a protein at a specific binding site, affecting function

Question 16

What are three examples of protein function related to binding?

Answer 16

• Antibodies
• Enzymes
• Motor proteins

Question 17

What interactions influence protein folding?

Answer 17

Hydrophobic and hydrophilic interactions play a key role in protein folding

Question 18

What are the four major macromolecules?

Answer 18

• Proteins
• Lipids
• Carbohydrates
• DNA

Question 19

What is the biological significance of lipids?

Answer 19

• Store chemical energy
• Form cell membranes
• Act as hormones
• Provide waterproofing

Question 20

What are the key characteristics of lipids?

Answer 20

• Water insoluble
• Oily/greasy
• Composed of fatty acids

Question 21

What are triacylglycerols?

Answer 21

The most abundant lipids in the cells

Question 22

What are triacylglycerols composed of?

Answer 22

Glycerol esterified with three fatty acids

Question 23

What are triacylglycerols used for?

Answer 23

For fat storage in animals and plants

Question 24

Why are triacylglycerols important in energy storage?

Answer 24

They yield twice the energy per gram compared to carbohydrates

Question 25

What are the two types of triacylglycerols?

Answer 25

Simple - three of the same fatty acid Mixed - two or more different fatty acids

Question 26

What are sphingolipids?

Answer 26

Membrane lipids with a polar head and two non polar tails containing sphingosine instead of glycerol

Question 27

What are steroids and what is their most abundant form?

Answer 27

- Fat-soluble molecules with four fused rings - Cholesterol is the most abundant and a precursor for steroid hormones

Question 28

What are lipoproteins and what is their function?

Answer 28

Complexes that transport water insoluble lipids in blood, consisting of polar lipids, sterols and polypeptides

Question 29

What are the four classes of lipoproteins?

Answer 29

- Chylomicrons - Very low density lipoprotein - Low density lipoprotein - High density lipoprotein

Question 30

What is the relationship between lipoproteins and atherosclerosis?

Answer 30

High VLDL and low HDL levels are associated with an increased risk of atherosclerosis

Question 31

What are waxes and what are their functions?

Answer 31

Esters of fatty acids and long chain alcohols providing lubrication, waterproofing and pliability for skin, feathers, fur and hair

Question 32

What are trans fats and why are they harmful?

Answer 32

Trans fats are artificially hydrogenated fats that increase shelf life but raise the risk of heart disease by lowering HDL levels

Question 33

What are mucopolysaccharides?

Answer 33

Glycoproteins with a higher percentage of carbohydrate than protein

Question 34

What is an oligosaccharide?

Answer 34

A short chain of monosaccharides

Question 35

Why must animals cleave sucrose before absorbing it?

Answer 35

Sucrose is not directly absorbable and must be broken down by sucrase/invertase in the small intestine

Question 36

What are the storage polysaccharides in plants and what do they consist of?

Answer 36

Starch - amylose and amylopectin

Question 37

What are the storage polysaccharides in animals and what do they consist of?

Answer 37

Gylcogen - branched polysaccharide

Question 38

What is cellulose?

Answer 38

A fibrous water insoluble polysaccharide forming plant cell walls made of unbranched glucose chains

Question 39

What is peptidoglycan?

Answer 39

A bacterial cell wall component made of peptide and polysaccharide targeted by penicillin to inhibit bacterial growth

Question 40

What is heparin?

Answer 40

A mucopolysaccharide found in arterial blood vessels that inhibits blood clotting

Question 41

What is the glycemic index?

Answer 41

A ranking of carbohydrates based on their impact on blood glucose levels

Question 42

Why does DNA form a double helix?

Answer 42

The sugar phosphate backbone is hydrophilic while the bases are hydrophobic causing the helical structure