IAL NOTES BIOLOGY
CONTENTS
Topic 1 .................................................................................................................................................... 3
Water .................................................................................................................................................. 3
Carbohydrates .................................................................................................................................... 3
Fats ..................................................................................................................................................... 5
Heart ................................................................................................................................................... 6
Obesity indicators ............................................................................................................................. 16
The energy balance ............................................................................................................................17
Consequences of obesity....................................................................................................................17
Correlation and causation ................................................................................................................. 18
Topic 2 .................................................................................................................................................. 21
Gas Exchange.................................................................................................................................... 21
Cell Membrane .................................................................................................................................. 21
Transporatation ................................................................................................................................ 22
Proteins............................................................................................................................................. 24
Enzymes ........................................................................................................................................... 24
DNA .................................................................................................................................................. 25
Cystic Fibrosis ................................................................................................................................... 29
Topic 3 .................................................................................................................................................. 32
Structures of Cells ............................................................................................................................. 32
Protein Trafficking ............................................................................................................................ 34
Microscopes ...................................................................................................................................... 34
Human Fertilisation........................................................................................................................... 36
Genetic Variation from Meiosis ......................................................................................................... 37
Cell Cycle .......................................................................................................................................... 37
Meiosis .............................................................................................................................................. 39
Plant Fertilisation .............................................................................................................................. 40
, Stem Cells ......................................................................................................................................... 40
Gene expression ................................................................................................................................ 41
How cells are organised..................................................................................................................... 43
Polygenic inheritance ........................................................................................................................ 44
Topic 4 .................................................................................................................................................. 45
Cell Structure .................................................................................................................................... 45
Drug Development............................................................................................................................ 48
Classification ..................................................................................................................................... 50
Biodiversity ....................................................................................................................................... 52
Plant Transportation ......................................................................................................................... 58
Hardy-Weinberg Equilibrium............................................................................................................. 64
Unit 3 .................................................................................................................................................... 66
Core Practical 1 ................................................................................................................................. 66
Core Practical 2 ................................................................................................................................. 68
Core Practical 3 ..................................................................................................................................71
Core Practical 4 ................................................................................................................................. 74
Core Practical 5 ................................................................................................................................. 79
Core Practical 6 ................................................................................................................................. 82
Core Practical 7 ................................................................................................................................. 86
Core Practical 8 ................................................................................................................................. 88
Core Practical 9 ................................................................................................................................. 90
Websites ............................................................................................................................................... 93
2
,TOPIC 1
WATER
Understand the importance of water as a solvent in transport, including its dipole nature
• Water is a polar molecule= it has an unevenly distributed chemical charge
o The two hydrogens are pushed towards each other forming a V shaped molecule
o Hydrogen= slightly positive charge
o Oxygen= slightly negative charge (electrons are more concentrated at this end)
• Positively charged end of water molecule is attracted to the negative ends of surrounding
molecules
• Hydrogen bonding:
o Holds the water molecules together
o Results in water being liquid at room temperature
SOLVENT PROPERTIES
• Chemicals easily dissolve in water= biochemical reactions can occur in cytoplasm of cells
• Dissolved substances can be transported around organisms
o E.g. in animals via the blood and lymph systems
o E.g. in plants via the xylem and phloem
• Polar molecules dissolve easily in water molecules
• Polar groups e.g. –OH become surrounded by water and go into solution
• Polar substances= hydrophilic= water attracting
• Hydrophobic= non-polar, e.g. lipids do not dissolve in water> allows transport in blood
• A large amount of energy needed to break hydrogen bonds in water
o a large input of energy causes only a small increase in temperature= water warms up
and cools down slowly
CARBOHYDRATES
(i) know the difference between monosaccharides, disaccharides and polysaccharides, including glycogen and starch
(amylose and amylopectin)
(ii) be able to relate the structures of monosaccharides, disaccharides and polysaccharides to their roles in providing and
storing energy β-glucose and cellulose are not required in this topic.
TABLE: COMPARING CARBOHYDRATE STRUCTURE
Monosaccharides • are single sugar units Glucose
• formula (CH2O) n • main sugar used by cells for respiration
• have between 3-7 carbon • glucose subunits joined together→ starch
atoms + glycogen
• examples= glucose, • starch + glycogen digested→ glucose
galactose and fructose>are o can be absorbed and transported
known as hexose sugars in bloodstream to cells
Galactose
3
, • can provide rapid source of • part of disaccharide sugar lactose>found
energy in milk
• Are also readily absorbed • -OH, groups on carbon 1 + 4 lie on
and require little change opposite side of ring compared to glucose
before being used in cellular Fructose
respiration • Sugar that occurs naturally in fruit, honey
+ some vegetables
Disaccharides • Two single sugar units join in Sucrose
a condensation reaction→ • glucose + fructose= S
disaccharide • Sugar that is transported around
• Condensation reaction= a plant
water molecule is released Maltose
• Glycosidic bond forms • 2 glucose molecules= M
between two glucoses • Produced when amylase breaks
• Maltose is an example of a down starch
disaccharide • Found in germinating seeds e.g.
• Glycosidic bond broken by barley as they break down their
hydrolysis starch stores to use for food
• Hydrolysis of
carbohydrates> occurs when Lactose
they are digested in the gut • Galactose+ glucose
• And when carbohydrate • Is a sugar found in milk
stores in a cell are broken
down to release sugars
Polysaccharides • 3 main types= starch, Starch= storage carbohydrate in plants> made up
cellulose and glycogen of amylose + amylopectin
• They do not dissolve easily
• Starch + glycogen= energy Amylose
storage molecules within • Straight chain of glucose molecules
cells • 1,4 glycosidic links between adjacent
They are suitable for storage glucose molecules
• They are compact molecules • Position of hydrogen bonds that form
• Have low solubility in water between hydroxyl groups= causes
• This means they don’t affect chain to coil= spiral shape
concentration of water in in Amylopectin
cytoplasm= don’t affect • Polymer of glucose but has side branches
movement of water in and • 1,6 glycosidic link holds each side branch
out of body by osmosis onto main chain
know how monosaccharides (glucose, fructose and galactose) join together to form disaccharides (maltose, sucrose and lactose)
and polysaccharides (glycogen, amylose and amylopectin) through condensation reactions forming glycosidic bonds, and how
these can be split through hydrolysis reactions
STARCH
• Spiral structure and insoluble nature
4
CONTENTS
Topic 1 .................................................................................................................................................... 3
Water .................................................................................................................................................. 3
Carbohydrates .................................................................................................................................... 3
Fats ..................................................................................................................................................... 5
Heart ................................................................................................................................................... 6
Obesity indicators ............................................................................................................................. 16
The energy balance ............................................................................................................................17
Consequences of obesity....................................................................................................................17
Correlation and causation ................................................................................................................. 18
Topic 2 .................................................................................................................................................. 21
Gas Exchange.................................................................................................................................... 21
Cell Membrane .................................................................................................................................. 21
Transporatation ................................................................................................................................ 22
Proteins............................................................................................................................................. 24
Enzymes ........................................................................................................................................... 24
DNA .................................................................................................................................................. 25
Cystic Fibrosis ................................................................................................................................... 29
Topic 3 .................................................................................................................................................. 32
Structures of Cells ............................................................................................................................. 32
Protein Trafficking ............................................................................................................................ 34
Microscopes ...................................................................................................................................... 34
Human Fertilisation........................................................................................................................... 36
Genetic Variation from Meiosis ......................................................................................................... 37
Cell Cycle .......................................................................................................................................... 37
Meiosis .............................................................................................................................................. 39
Plant Fertilisation .............................................................................................................................. 40
, Stem Cells ......................................................................................................................................... 40
Gene expression ................................................................................................................................ 41
How cells are organised..................................................................................................................... 43
Polygenic inheritance ........................................................................................................................ 44
Topic 4 .................................................................................................................................................. 45
Cell Structure .................................................................................................................................... 45
Drug Development............................................................................................................................ 48
Classification ..................................................................................................................................... 50
Biodiversity ....................................................................................................................................... 52
Plant Transportation ......................................................................................................................... 58
Hardy-Weinberg Equilibrium............................................................................................................. 64
Unit 3 .................................................................................................................................................... 66
Core Practical 1 ................................................................................................................................. 66
Core Practical 2 ................................................................................................................................. 68
Core Practical 3 ..................................................................................................................................71
Core Practical 4 ................................................................................................................................. 74
Core Practical 5 ................................................................................................................................. 79
Core Practical 6 ................................................................................................................................. 82
Core Practical 7 ................................................................................................................................. 86
Core Practical 8 ................................................................................................................................. 88
Core Practical 9 ................................................................................................................................. 90
Websites ............................................................................................................................................... 93
2
,TOPIC 1
WATER
Understand the importance of water as a solvent in transport, including its dipole nature
• Water is a polar molecule= it has an unevenly distributed chemical charge
o The two hydrogens are pushed towards each other forming a V shaped molecule
o Hydrogen= slightly positive charge
o Oxygen= slightly negative charge (electrons are more concentrated at this end)
• Positively charged end of water molecule is attracted to the negative ends of surrounding
molecules
• Hydrogen bonding:
o Holds the water molecules together
o Results in water being liquid at room temperature
SOLVENT PROPERTIES
• Chemicals easily dissolve in water= biochemical reactions can occur in cytoplasm of cells
• Dissolved substances can be transported around organisms
o E.g. in animals via the blood and lymph systems
o E.g. in plants via the xylem and phloem
• Polar molecules dissolve easily in water molecules
• Polar groups e.g. –OH become surrounded by water and go into solution
• Polar substances= hydrophilic= water attracting
• Hydrophobic= non-polar, e.g. lipids do not dissolve in water> allows transport in blood
• A large amount of energy needed to break hydrogen bonds in water
o a large input of energy causes only a small increase in temperature= water warms up
and cools down slowly
CARBOHYDRATES
(i) know the difference between monosaccharides, disaccharides and polysaccharides, including glycogen and starch
(amylose and amylopectin)
(ii) be able to relate the structures of monosaccharides, disaccharides and polysaccharides to their roles in providing and
storing energy β-glucose and cellulose are not required in this topic.
TABLE: COMPARING CARBOHYDRATE STRUCTURE
Monosaccharides • are single sugar units Glucose
• formula (CH2O) n • main sugar used by cells for respiration
• have between 3-7 carbon • glucose subunits joined together→ starch
atoms + glycogen
• examples= glucose, • starch + glycogen digested→ glucose
galactose and fructose>are o can be absorbed and transported
known as hexose sugars in bloodstream to cells
Galactose
3
, • can provide rapid source of • part of disaccharide sugar lactose>found
energy in milk
• Are also readily absorbed • -OH, groups on carbon 1 + 4 lie on
and require little change opposite side of ring compared to glucose
before being used in cellular Fructose
respiration • Sugar that occurs naturally in fruit, honey
+ some vegetables
Disaccharides • Two single sugar units join in Sucrose
a condensation reaction→ • glucose + fructose= S
disaccharide • Sugar that is transported around
• Condensation reaction= a plant
water molecule is released Maltose
• Glycosidic bond forms • 2 glucose molecules= M
between two glucoses • Produced when amylase breaks
• Maltose is an example of a down starch
disaccharide • Found in germinating seeds e.g.
• Glycosidic bond broken by barley as they break down their
hydrolysis starch stores to use for food
• Hydrolysis of
carbohydrates> occurs when Lactose
they are digested in the gut • Galactose+ glucose
• And when carbohydrate • Is a sugar found in milk
stores in a cell are broken
down to release sugars
Polysaccharides • 3 main types= starch, Starch= storage carbohydrate in plants> made up
cellulose and glycogen of amylose + amylopectin
• They do not dissolve easily
• Starch + glycogen= energy Amylose
storage molecules within • Straight chain of glucose molecules
cells • 1,4 glycosidic links between adjacent
They are suitable for storage glucose molecules
• They are compact molecules • Position of hydrogen bonds that form
• Have low solubility in water between hydroxyl groups= causes
• This means they don’t affect chain to coil= spiral shape
concentration of water in in Amylopectin
cytoplasm= don’t affect • Polymer of glucose but has side branches
movement of water in and • 1,6 glycosidic link holds each side branch
out of body by osmosis onto main chain
know how monosaccharides (glucose, fructose and galactose) join together to form disaccharides (maltose, sucrose and lactose)
and polysaccharides (glycogen, amylose and amylopectin) through condensation reactions forming glycosidic bonds, and how
these can be split through hydrolysis reactions
STARCH
• Spiral structure and insoluble nature
4
