1.2 — carbohydrates: introduction

Question 1

what are carbohydrates?

Answer 1

carbohydrates are molecules that contain the elements carbon, hydrogen and oxygen

Question 2

what does the ‘carbo’ in carbohydrates show about a biological molecule?

Answer 2

that the molecule contains the element carbon

Question 3

what does the ‘hydrate’ in carbohydrates show about a biological molecule?

Answer 3

that it contains hydrogen and oxygen atoms in a ratio of 2:1 (like water — H₂O)

Question 4

what is the general formula for a carbohydrate?

Answer 4

C_x(H₂O)_Y

Question 5

what are the 5 roles of carbohydrates in living organisms?

Answer 5

1. energy supply for cells — the main role
2. energy storage — sugars can be stored as complex carbohydrates (e.g. starch of glycogen)
3. structural components — cellulose and chitin are used in cell walls
4. cellular recognition — glycoproteins help cells identify each other and communicate
5. building blocks for biological molecules — deoxyribose and ribose can be used to make nucleic acids

Question 6

how many subunits does a monosaccharide contain?

Answer 6

one

Question 7

give three examples of a monosaccharide:

Answer 7

glucose, fructose and galactose

Question 8

what is a monosaccharide’s main function?

Answer 8

energy source

Question 9

how many subunits does a disaccharide contain?

Answer 9

two

Question 10

give three examples of a disaccharide:

Answer 10

maltose, sucrose and lactose

Question 11

what is a disaccharide’s main function?

Answer 11

transport form

Question 12

how many subunits does a polysaccharide have?

Answer 12

many

Question 13

give three examples of a polysaccharide:

Answer 13

starch, glycogen, cellulose

Question 14

what is a polysaccharide’s main function?

Answer 14

storage form