Biological molecules

Question 1

elements in biological molecules

Answer 1

carbohydrates- CHO
Lipids- CHO
Protein- CHON
Nucleic acid- CHONP

Question 2

condensation

Answer 2

removal of water to form a chemical bond between two molecules

Question 3

hydrolysis

Answer 3

addition of water to break a chemical bond between two molecules

Question 4

Known cations

Answer 4

calcium = Ca2+ = used in nerve impulse transmission, muscle contraction and as a cofactor for enzymes

sodium = Na+ = used in generating nerve impulses, muscle contraction and co-transport of glucose and amino acid

potassium = K+ = used in generating nerve impulses, muscle contraction and regulating fluid balance

hydrogen = H+ = determine pH of solutions and used in photosynthesis reactions

ammonium = NH4+ = source of nitrogen in plants

iron = Fe2+ = bind to oxygen within haemoglobin

Question 5

Known anions

Answer 5

chloride = Cl- = maintains blood pH in gas exchange and cofactor for amylase enzyme

phosphate = PO4 3- = components of nucleotides and phospholipids and bonds store energy in ATP

hydroxide = OH- = determines pH of solutions

nitrate = NO3- = source of nitrogen

hydrogen carbonate = HCO3- = maintains blood pH

Question 6

Water

Answer 6

.is polar as shared electrons are pulled towards the oxygen atom make the oxygen slightly negative and the hydrogen slightly positive

.can form hydrogen bonds as the partially positive hydrogen attracts towards the partially negative oxygen of an another molecule

Question 7

Roles of water

Answer 7

.solvent as many substances can dissolve in it
.can act as a buffer as it has a high specific heat capacity
.cooling mechanism as mammals can use the evaporation of water in sweat to cool skin = high latent heat of vaporisation
.habitat for aquatic animals
.metabolite as many chemical reactions involve water
.transport due to cohesion and adhesion

Question 8

Roles of Carbohydrates

Answer 8

.energy supply for cells
.energy storage e.g. starch and glycogen
.structural components e.g. cellulose and chitin
.building block for biological molecules e.g. deoxyribose and ribose are used to make nucleic acids

Question 9

monosaccharide

Answer 9

glucose, fructose and galactose and are used as a energy source

Question 10

disaccharide

Answer 10

maltose, sucrose and lactose and are the transport form for the monosaccharide

Question 11

polysaccharide

Answer 11

starch, glycogen and cellulose and are the storage form of the monosaccharide

Question 12

Monosaccharides hexose sugars

Answer 12

glucose, fructose and galactose

Question 13

Monosaccharides pentose sugars

Answer 13

ribose and deoxyribose

Question 14

Properties of glucose

Answer 14

.soluble in water making it easier to be transported around organisms
.bonds hold a lot of energy which are released when broken

Question 15

Disaccharides

Answer 15

maltose- glucose + glucose

sucrose- glucose + fructose

lactose- glucose + galactose

Question 16

starch

Answer 16

used by plants to store excess glucose and is made of many alpha glucose monomers joined by glyosidic bonds to form amylose and amylopectin