Chapter 4: Biological Molecules

Question 1

Carbohydrates

Answer 1

Made of carbon, hydrogen, oxygen
source of energy for body
3 types:
monosaccharides: simplest form, glucose, easy digest
disaccharides: 2 monosaccharides together
polysaccharides: large chain of monosaccharides (starch made of chains of glucose and glycogen), longer digest

Question 2

Test for carbs

Answer 2

Mono/disaccharide (glucose, glycogen): Benedict’s Test
Polysaccharides (starch): Iodine Test

Benedict’s test: positive= brick red, negative= blue
Iodine Test: positive= blue-black, negative= yellow

Question 3

Lipids

Answer 3

carbon, hydrogen, oxygen
Made of triglycerides
1 glycerol molecule bonded to 3 fatty acid chains
2 groups of lipids: Fat (solid at room temp), Oil (liquid at room temp)
source of energy and cushioning for organs

Question 4

Test for fats

Answer 4

emulsion test/ Sudan III test

positive: milky-white emulsion
negative: no emulsion

Question 5

Proteins

Answer 5

repair and build body tissues, enzymes
made of long chains of amino acids
made of carbon, hydrogen, oxygen, nitrogen, and sulfur.
3 types: amino acids, peptides, polypeptides

Question 6

Test for proteins

Answer 6

Biuret test
Positive: Purple
Negative: Blue