Biology Grade 10 Term 2 pt.2
Topic 1: Organic Compounds ⚗️
Contains the elements
● Carbon
● Hydrogen
● Oxygen
● Nitrogen
● Phosphorus
Carbohydrates 🍞
● Contains Carbon, Oxygen & Hydrogen (Carbo/hydrates)
● Source of energy for living organisms
● Eg Glucose, Fructose, Sucrose, Starch & Cellulose
Types of Carbohydrates
● Monosaccharide
○ Most simple sugars like glucose & fructose. Are the building blocks of Carbs
○ Glucose Test- Use Benedict’s solution or Fehling’s A & B solutions. If glucose
is present these solutions turn red-brown when heated ***
● Disaccharide
○ 2 Saccharides (sugars) form together to form sucrose or maltose. Sucrose is
used as sugar in food (Sugarcane) 🎋
○ Lactose is also a disaccharide 🥛
● Polysaccharide
○ 3 or more saccharides
○ Most common- Starches, glycogen, and cellulose.
○ Starch- Found in products like wheat, maze & rice. Starches are used to
store energy in organisms. During digestion, starch is broken down into
glucose & is used by the mitochondria to produce energy during cellular
respiration
○ Glycogen- If human blood has too much
glucose, The pancreas will secrete insulin to
secrete insulin to lower blood glucose levels
■ This causes the glucose to convert to
a starch called glycogen which is
stored in the liver & muscle.
○ Cellulose- Found in Plant cell walls, not animals. Humans cannot absorb it
but it can be done by animals e.g Fibre or roughage
○ Iodine test- Turns iodine solution blue-black in the presence of starch. ***
, Lipids (Oils, Fats)
● Contains
○ Carbon (C)
○ Hydrogen (H)
○ Oxygen (O)
○ Some lipids called phospholipids contain Phosphorus (P)
● A lipid test is done with organic solvents. Eg Ether
● Importance: Stores energy in animals & forms part of the membrane
Structure of Lipids
● Building blocks are: 1 Glycerol & 3 fatty acids
● It consists of oxygen, hydrogen, and carbon
● When a lipid molecule is broken down, it releases a lot of energy
● Lipids can be solid or liquid at room temp. This depends on the type
of fatty acids
Unsaturated fats: From plants; liquid at room temperature; healthier than saturated fats
Saturated fats: From animals; Solid at room temperature; linked to high blood cholesterol
Protein 🦾
● Made up of
￮ Carbon ￮ Oxygen
￮ Nitrogen ￮ Hydrogen
● May also contain
￮ Sulphur ￮ Phosphorus
￮ Iron
● Test: Millon’s reagent (turns brick red) / Biuret test (turns violet)***
Importance
● Important for the functioning of cells
● Enzymes that keep cells alive
● Form parts of body tissues (Eg muscles) & body structures (Eg Nail, wool & hair)
● Functions of protein include carrying O2, Forming antibodies (attack invading
bacteria) & forming hormones that regulate body functions
● Sensitive to temperature and pH levels
Building Blocks- Amino Acids
● 20 different amino acids combined in different ways to make thousands of proteins
Topic 1: Organic Compounds ⚗️
Contains the elements
● Carbon
● Hydrogen
● Oxygen
● Nitrogen
● Phosphorus
Carbohydrates 🍞
● Contains Carbon, Oxygen & Hydrogen (Carbo/hydrates)
● Source of energy for living organisms
● Eg Glucose, Fructose, Sucrose, Starch & Cellulose
Types of Carbohydrates
● Monosaccharide
○ Most simple sugars like glucose & fructose. Are the building blocks of Carbs
○ Glucose Test- Use Benedict’s solution or Fehling’s A & B solutions. If glucose
is present these solutions turn red-brown when heated ***
● Disaccharide
○ 2 Saccharides (sugars) form together to form sucrose or maltose. Sucrose is
used as sugar in food (Sugarcane) 🎋
○ Lactose is also a disaccharide 🥛
● Polysaccharide
○ 3 or more saccharides
○ Most common- Starches, glycogen, and cellulose.
○ Starch- Found in products like wheat, maze & rice. Starches are used to
store energy in organisms. During digestion, starch is broken down into
glucose & is used by the mitochondria to produce energy during cellular
respiration
○ Glycogen- If human blood has too much
glucose, The pancreas will secrete insulin to
secrete insulin to lower blood glucose levels
■ This causes the glucose to convert to
a starch called glycogen which is
stored in the liver & muscle.
○ Cellulose- Found in Plant cell walls, not animals. Humans cannot absorb it
but it can be done by animals e.g Fibre or roughage
○ Iodine test- Turns iodine solution blue-black in the presence of starch. ***
, Lipids (Oils, Fats)
● Contains
○ Carbon (C)
○ Hydrogen (H)
○ Oxygen (O)
○ Some lipids called phospholipids contain Phosphorus (P)
● A lipid test is done with organic solvents. Eg Ether
● Importance: Stores energy in animals & forms part of the membrane
Structure of Lipids
● Building blocks are: 1 Glycerol & 3 fatty acids
● It consists of oxygen, hydrogen, and carbon
● When a lipid molecule is broken down, it releases a lot of energy
● Lipids can be solid or liquid at room temp. This depends on the type
of fatty acids
Unsaturated fats: From plants; liquid at room temperature; healthier than saturated fats
Saturated fats: From animals; Solid at room temperature; linked to high blood cholesterol
Protein 🦾
● Made up of
￮ Carbon ￮ Oxygen
￮ Nitrogen ￮ Hydrogen
● May also contain
￮ Sulphur ￮ Phosphorus
￮ Iron
● Test: Millon’s reagent (turns brick red) / Biuret test (turns violet)***
Importance
● Important for the functioning of cells
● Enzymes that keep cells alive
● Form parts of body tissues (Eg muscles) & body structures (Eg Nail, wool & hair)
● Functions of protein include carrying O2, Forming antibodies (attack invading
bacteria) & forming hormones that regulate body functions
● Sensitive to temperature and pH levels
Building Blocks- Amino Acids
● 20 different amino acids combined in different ways to make thousands of proteins
