Biomolecules: Lipids

Question 1

Lipids - Background

Answer 1

Soluble in non polar solvent but not in water
Mainly Carbon Hydrogen with few O in functional group
Groups of lipids include fats, phospholipids, carotenoids, steroids, waxes
Used for energy storage, structural components of cell membranes and in key hormones

Question 2

Fats

Answer 2

Triacylglycerol- the main storage lipid
-OH from glycerol is replaced with fatty acid e.g. palmitic acid, oleic acid releasing water in the process.
Most abundant lipid
Form of reserve fuel storage
Consists of glycerol joined with 3 fatty acids
Glycerol is a three Carbon alcohol with 3 hydroxyl (-OH) groups

Question 3

Fatty acids

Answer 3

a long unbranched hydrocarbon

Question 4

Saturated

Answer 4

contain max possible number of Hydrogen atoms in animal fat and solid vegetable shortening

Question 5

Unsaturated

Answer 5

Include one or more adjacent pairs of carbon atoms joined by a double bond

Question 6

Monounsaturated fatty acid

Answer 6

one double bond

Question 7

Polyunsaturated fatty acid

Answer 7

more than one double bond

Question 8

Phospholipids

Answer 8

Amphipathic lipids polar and non polar component
2 fatty acids(non polar) with phosphate (polar) attached to glycerol
2 ends differ physically and chemically
Uniquely suited to function as fundamental components of cell membranes
Forms a lipid bi-layer
Hydrophobic - fatty acids
Hydrophilic - choline, phosphate and glycerol

Question 9

Steroids

Answer 9

Influence behaviour of cells
Carbon atoms in four attached rings
Consist of isoprene units but produced in the body
Cholesterol, bile salts etc
Involved  in regulating metabolism

Question 10

Carotenoids

Answer 10

Orange and yellow plant pigments
Insoluble in water and have oil consistency
Play a role in photosynthesis
Consist of isoprene unit - specific group of carbon chain join 1 by 1
Animals convert it into Vitamin A
Isoprene - Derived Compounds

Question 11

Nucleic Acids

Answer 11

Transmit hereditary information info transferred from 1 gen. to another in the same species. Important function in phenotype determine structure of proteins
Determine what proteins a cells manufacture
2 classes in cells are - DNA
- RNA
Polymers of nucleotides

Question 12

Component of Nucleotides

Answer 12

Five carbon sugar Deoxyribose (DNA) or Ribose (RNA)
One or more phosphate groups
Nitrogenous base of either a double ring purine or a single ring pyrimidine
Nitrogen bases
Adenine Thymine Guanine, Cytosine

Question 13

DNA

Answer 13

Double stranded helix- 2 chains
Adenine pairs with Thymine. Cytosine pairs with Guanine.
Mirror of itself

Question 14

RNA

Answer 14

Single stranded
No thymine - replaced with uracil
Nucleotides are joined by phosphodiester linkages

Question 15

Nucleotides

Answer 15

ATP, GTP, cAMP, cGMP, NAD+

Question 16

ATP

Answer 16

High energy currency in the cell
Releases energy when broken in the mitochondria
Drives metabolic energy in the cell
Adenine ribose three phosphate 2 of which are joined by a covalent bond and can transfer a phosphate into another molecule and making it more reactive thus donating chemical energy

Question 17

GTP

Answer 17

Guanine Triphosphate
Nucleotide with guanine and 3 phosphates to transfer energy with
Used for cell signalling

Question 18

Cyclic AMP

Answer 18

Cyclic Adenosine Monophosphate
Converted from ATP by the enzyme adenylyl cyclase
Regulates certain cell functions e.g cell signalling
Identify hormones in circulating the body on the surface of the cell
Hormone doesn’t go in the cell but the activity does

Question 19

cGMP

Answer 19

Cyclic Guanosine Monophosphate

Plays a role in certain signalling processes

Question 20

NAD+

Answer 20

Dinucleotide
Nicotinamide adenine dinucleotide
Involved in oxidation and reduction reactions in cells
Oxidation (NAD+) and reduction (NADH)
These electrons that are involved in redox reactions are transferred to other molecules