Biological Molecules

Question 1

What are the 3 main functions of Lipids?

Answer 1

1)Insulation
2)Energy Storage
3) Protection

Question 2

What are the two type of lipids?

Answer 2

Triglycerides and Phospholipids

Question 3

What kind of reaction and what ‘reactants’ are used to make triglycerides?

Answer 3

CONDENSATION reaction 3 fatty acids and 1 molecule of Glycerol and 3 molecule of water formed

Question 4

What kind bond is present in Triglycerides and How is it formed?

Answer 4

An ester bond and the OH from glycerol and the H from fatty acid chain

Question 5

What are the properties of Triglycerides and why ?
[Hint3]

Answer 5

1) Energy Storage- high ratio of carbon-Hydrogen(C-H) bond to Carbon-Carbon(C-C) bonds
2)Low mass-Lots can be present without affecting organism ability to walk.etc..
3)Insoluble- Fatty Acid chain are Hydrophobic

Question 6

How are Phospholipids formed?

Answer 6

One fatty Acid is replaced by Phosphate-Containing group
So
1 Molecule of glycerol, 2xfatty acid chains and 1 phosphate- containing group

Question 7

What is the structure and property of Phospholipid?

Answer 7

Fatty Acid chains are HYDROPHOBIC and Phosphate heads are hydrophilic so polar molecule= PHOSPHOLIPID BILAYER

Question 8

What is a Saturated and Unsaturated fatty acid chains?

Answer 8

Saturated= Single carbon-carbon bonds
Unsaturated= AT LEAST one double- double carbon bond

Question 9

What is the test for lipids?

Answer 9

1)Shake sample with ethanol
2)Add water
3)If lipid present cloudy white milky emulsion

Question 10

Give me the type of Monosaccharides?

Answer 10

Glucose, Galactose and Fructose.

Question 11

What is a condensation reaction?

Answer 11

Joining molecules to form a chemical bond excluding water so water produced.

Question 12

What are the type of glucose molecules?

Answer 12

Alpha with the Hydroxyl on top
Beta with the Hydroxyl at the bottom
[A FIRST so A top …]

Question 13

What is the chemical bond in Carbohydrates?

Answer 13

Glycosidic Bond

Question 14

What are the type of Disaccharides?

Answer 14

Maltose= 2 ALPHA Glucose
Sucrose= Glucose + Fructose
Galactose= Glucose+Lactose

Question 15

What are the polysaccharides you need to know about?

Answer 15

Starch, Glycogen and Cellulose

Question 16

Give the properties and the type of Glucose in starch and the structure of Starch?

Answer 16

Starch present in Starch
Polymer of Alpha Glucose
Starch has a helical structure so compact so easily hydrolysed into Alpha Glucose for respiration
Insoluble won’t affect water potential important in plants

Question 17

What are the properties of Glycogen and type of Glucose?

Answer 17

Glycogen is animal starch
Glycogen polymer of Alpha Glucose
Glycogen is Highly branched so readily hydrolysed into Alpha Glucose for uses in respiration.SO ENABLES TO ACT AS A STORAGE MOLECULE

Question 18

What is the glucose present in cellulose and the properties and structure of cellulose?

Answer 18

Cellulose present in Plant cell walls
Cellulose polymer of Beta Glucose so molecules are inverted- Arrangement of Atoms must ADOPT THIS configuration so GLYCOSIDIC BOND FORMATION EASIER

Question 19

What give cellulose ability to act as a cell wall?

Answer 19

Cellulose have straight chain of cellulose so hydroxyls group can form hydrogen bonds with other chain of cellulose hydroxyl group
Hydrogen bonds form tough fibres called Fibrils give cellulose High Tensile strength supporting role of Cell wall

Question 20

What is the test for Reducing Sugar?

Answer 20

Add Benedict’s Reagent- HEAT= BRICK RED PRECIPITATE

Question 21

What is the test for Non-Reducing Sugar?

Answer 21

Add HCL-BOIL then add Alkali such as NAHCO3
Add Benedict’s Reagent-HEAT and Brick red precipitatewould form