IB BIO TOPIC 3.2 : CARBOHYDRATES, PROTEINS & LIPIDS

Question 1

Distinguish between organic and inorganic compounds (°3)

Answer 1

1. Compounds containing carbon that are found in living organisms are regarded as organic.
2. Exceptions :

Carbonates (ex. CaCO3)

Hydrogen Carbonates (ex. HCO3)

Oxide of Carbon (ex. CO, CO2)

3. All other compounds are regarded as Inorganic.

Question 2

Amino Acid Structure

Answer 2

Question 3

Glucose Structure

Answer 3

Question 4

Ribose structure

Answer 4

Question 5

Fatty Acid

Answer 5

Question 6

Give 3 exemples of monosaccharides

Answer 6

1. Glucose
2. Fructose
3. Galactose

Question 7

Give 3 exemples of disaccharides

Answer 7

1. Sucrose
2. Maltose
3. Lactose

Question 8

Give 3 exemples of polysaccharides

Answer 8

1. Cellulose
2. Glycogen
3. Starch

Question 9

Mono : Glucose + Glucose =

Answer 9

Di : Maltose

Question 10

Mono : Galactose + Glucose =

Answer 10

Di : Lactose

Question 11

Mono : Glucose + Fructose =

Answer 11

Di : Sucrose

Question 12

List the function of glucose in animals

Answer 12

Monosaccharide : major energy source for fueling cellular respiration

Question 13

List the function of lactose in animals :

Answer 13

Disaccharide : Energy source found in mammalian milk.

Question 14

List the function of glycogen in animals

Answer 14

Polysaccharide : Energy storage in liver.

Question 15

List the function of Fructose in plants

Answer 15

Monosaccharide : Energy component in flower nectar.

Question 16

List the function of Sucrose in plants

Answer 16

Disaccharide : Energy molecule transported via phloem.

Question 17

List the function of cellulose in plants

Answer 17

Polysaccharide : Major structural component of plant wall cell.

Question 18

Ouline 3 roles of condensation synthesis

Question 19

Outline 3 roles of Hydrolysis

Answer 19

1. Polymers breoken down (= catabolized) into monomers (as in digestion)
2. With H2O used as a source of -H and a - OH group
3. Catalyzed by enzymes.

Question 20

Condensation synthesis =

Answer 20

Monomers ANABOLIC ⇒ Polymer

ex. Maltose + Water (Hydrolysis) to form Glucose + Glucose

Question 21

Hydrolysis =

Answer 21

Polymers CATABOLIC ⇒ Monomers

ex. Glucose + Glucose (Condensation synthesis) to form Maltose + Water

Question 22

3 ° Condensation synthesis in Fatty acids, Glycerol, Tryglycerides

Answer 22

1. Three separate condensation synthesis reactions
2. Link three fatty acid monomers to a single glycerol monomer.
3. Forming one triglyceride molecule and three H2O molecules.

Question 23

Hydrolysis in Fatty acids, Glycerol and Triglycerides

3 facts :

Answer 23

1. A triglyceride is broken down into one glycerol and three fatty molecules.
2. With three H2O molecules used as a source of -H and a -OH groups.
3. Catalyzed by enzymes.

Question 24

Condensation synthesis in Amino Acids and polypeptides

Answer 24

1. 2 amino acid monomers are linked to form a dipeptide
2. Releasing one H2O molecule
3. Repeated condensation synthesis reactions produce polypeptides (=proteins)

Question 25

Hydrolysis in Amino acids and Polypeptides

Answer 25

1. A polypeptide is broken down into two separate amino acid molecules. 2. With H2O molecules used as a source of -H and a -OH groups. 3. Catalyzed by enzymes

Question 26

State the 2 facts in the function of **energy source** in a lipid :

Answer 26

1. Concentrated long-term energy storage 2. Which can release fuel for cellular respiration as needed.

Question 27

State 1 facts of the **Phospholipid** function in a lipid

Answer 27

1. Structural framework of cellular membrane

Question 28

State 1 fact about the function of **thermal insulation** in a lipid:

Answer 28

1. Hormones = Messenger molecules.

Question 29

Give 2 comparisons of the use of **carbohydrates **in energy storage :

Answer 29

1. Glucose, when in excess, linked together by condensation synthesis to form polysaccharides. 2. Such as starch, glycogen and chitin.

Question 30

Give 4 facts about the use of starch in energy storage :

Answer 30

1. It is the primary energy storage compund in plants, with alpha-glucose 2. Forming either as amylose (unbranched chains) 3. Amylopectin (branched chains) 4. Long-term storage.

Question 31

Give 4 facts on the use of Glycogen in energy storage :

Answer 31

1. A branched polysaccharide formed from alpha-glucose 2. Primary energy storage compound in animals. 3. Found mainly in liver and muscle cells. 4. Short-term storage

Question 32

LIPIDS : State 3 facts on the use of triglycerides in energy storage :

Answer 32

1. A primary long-term energy storage compound 2. Containing twice the amount of energy per unit mass or volume as do either carbohydrates or proteins. 3. Long-term storage

Question 33

LIPIDS : Give 3 facts about the use of C-H bonds in energy storage :

Answer 33

1. Along the length of fatty acids are evry stable 2. Because the electrons in the C-H bond are equally shared. 3. Thus, when these bonds are broken, they yield large sums of energy.