Macromolecules and enzymes

Question 1

What is a macromolecule and what are they?

Answer 1

Complex, large, organic molecules:
-Carboydrates (sugars)
-Lipids (fats and oils)
-Proteins
-Nucleic acids (RNA and DNA)

Question 2

What is the difference between monomer and polymer?

Answer 2

-Monomer: macromolecule made of one unit
-Polymer: macromolecule made of many monomer subunits

Question 3

What are the monosaccharides of carbohydrates?

Answer 3

Glucose, fructose, galactose, deoxyribose and ribose

Question 4

What are the disaccharides of carbohydrates?

Answer 4

-Lactose (glucose + galactose)
-Sucrose (glucose + fructose)
-Maltose (2 glucoses)

Question 5

What are the polysaccharides of carbohydrates?

Answer 5

Starch, cellulose, and glycogen

Question 6

Define starch

Answer 6

Polymer of glucose, used by plants to store energy, digestible

Question 7

Define cellulose

Answer 7

Polymer of glucose, component of plant’s cell wall, indigestible

Question 8

Define glycogen

Answer 8

Polymer of glucose, stored in animal tissues (muscles and liver)

Question 9

What are the functions of carbohydrates?

Answer 9

-Glucose is the favorite fuel for cells (ATP is produced during glucose breakdown process)
-Combine with other macromolecules to form cell structures (glycoproteins and glycolipids)

Question 10

What are lipids and its major groups?

Answer 10

-Hydrophobic (don’t mix with water)
-3 groups: triglycerides, phospholipids, and steroids (sterol)

Question 11

What are triglycerides?

Answer 11

-Abundant in body tissues (as fat)
-Structure: glycerol backbone + 3 fatty acids

Question 12

Structure of diglyceride?

Answer 12

Glycerol + 2 fatty acids

Question 13

Structure of monoglyceride?

Answer 13

Glycerol + 1 fatty acid

Question 14

How can triglycerides vary?

Answer 14

Fatty acids vary:
-Length (n.b of carbon atoms)
-Degree of saturation (presence/absence of carbon double bonds)

Question 15

What are saturated fats?

Answer 15

No double carbon bond, animal source, solid or semi-solid at RT (ex: butter)

Question 16

What are unsaturated fats?

Answer 16

Double carbon bonds, plant source, liquid at RT (ex: olive oil)

Question 16

What are the functions of triglycerides)

Answer 16

-Important fuel source for the body
-Help with the absorption of fat-soluble vitamins
-Insulation and protection

Question 16

What are phospholipids?

Answer 16

-Modified triglycerides:
Glycerol backbone + 2 fatty acids and phosphate group
Hydrophilic head and hydrophobic tail
-Major structural components of the cell membrane

Question 17

What are steroids?

Answer 17

-Structure: 4 hydrocarbon rings joined together + side chain
-Synthesized by both plants and animals
-Cholesterol is very important for humans (bile acids, hormones, vitamins)

Question 18

What are proteins?

Answer 18

Their building blocks are amino acids linked by peptide bonds

Question 19

What are the 3 parts of amino acids?

Answer 19

-Carboxyl group (-COOH)
-Amino group (-NH3)
-Variable side chain (R-group) makes 20 unique amino acids

Question 20

What are the structure/names of proteins?

Answer 20

The carboxyl and amino groups bond together to form peptide bond
-Dipeptide (2 amino acids)
-Tripeptide (3 amino acids)
-Polypeptide (fewer than 100 amino acids)
-Protein (more than 100 amino acids)

Question 21

What are the protein structural levels?

Answer 21

-Primary structure
-Secondary structure
-Tertiary structure
-Quaternary structure

Question 22

Define primary structure

Answer 22

Sequence/order of amino acids

Question 23

Define secondary structure

Answer 23

Alpha helices and pleated sheets

Question 24

Define tertiary structure

Answer 24

Folding alpha helices and pleated sheets (3D) (functional protein)

Question 25

Define quaternary structure

Answer 25

Assembly of many folded polypeptides (many subunits)

Question 26

What are the functions of proteins?

Answer 26

-Structural (Keratin in nails and hair)
-Movement (Actin and myosin in muscle cells)
-Defense (Antibodies of the immune system are proteins)
-Storage (Albumin in egg white provides nutrients for the embryo)
-Signaling (Growth hormone is a hormonal messenger)
-Catalyzing reactions (Amylase is an enzyme that breaks down starch)

Question 27

What are enzymes?

Answer 27

Proteins with a very specific function:
-Catalysts increase rate of reactions
-Enzymes are biological catalysts
-Lower required activation energy

Question 28

What are catalyzed reactions?

Answer 28

-Anabolic rx = Synthesis (energy stored) (2 substrates = 1 product)
-Catabolic rx = Breakdown (energy released) (1 substrate = 2 products)