Chandi Palawela. Royal College B.Sc. (Hons -First Class); PG.Dip.in Edu Tel: 0718 617591 1 Unit 2 – Chemical & cellular basis of life Competency 2.1.0 : Investigates the chemical basis of life. Competency Level 2.1.1 : Inquires into the elemental composition of living bodies. Number of Periods : 02 . Guidelines: Elemental composition of living matter Among the 92 naturally occurring elements, about 20 elements constitute the living matter. Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus and Sulphur are the six most abundant elements. Exact composition of elements in organism can vary. However some elements are named as essential elements. They are separated in to macro elements and trace elements depending on their abundance in living matter. Macro elements Found 0.01% or more in the dry weight of an organism. C, H, O, N, P, S, Ca, K, Mg are found as macro elements in all organisms. In some organisms e.g. Human Na, Fe and Cl are also found as macro molecules. Trace elements Found less than 0.01% in dry weight Cl, Si, V, Cr, Co, B, Mn, Zn, Cu, Mo,I,Fe,Al etc. Functions of macro elements and trace elements Competency 2.1.0 : Investigates the chemical basis of life. Competency Level 2.1.2 : Investigates the physical and chemical properties of water important for life. Number of Periods : 02 Learning Outcomes : The Student should be able to:explain the importance of water for life. Describe physical and chemical properties of water which are important for life. Relate the physical and chemical properties of water to its functions performed in living systems. Guidelines : Importance of water for life. The most abundant inorganic compound in living matter is water. The main functions of water in organisms. 1. Component of protoplasm 2. Solvent 3. Reactant 4. Maintaining turgidity Other functions-Refer the note.
16
Embed
Unit 2 – Chemical & cellular basis of life -tute 2.pdfUnit 2 – Chemical & cellular basis of life ... Dilute HCl/H2SO4 , ... 1% starch solution in a test tube and add a few drops
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Chandi Palawela. Royal College B.Sc. (Hons -First Class); PG.Dip.in Edu Tel: 0718 617591
1
Unit 2 – Chemical & cellular basis of life Competency 2.1.0 : Investigates the chemical basis of life. Competency Level 2.1.1 : Inquires into the elemental composition of living bodies. Number of Periods : 02 . Guidelines: Elemental composition of living matter Among the 92 naturally occurring elements, about 20 elements constitute the living matter. Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus and Sulphur are the six most abundant elements. Exact composition of elements in organism can vary. However some elements are named as essential elements. They are separated in to macro elements and trace elements depending on their abundance in living matter. Macro elements Found 0.01% or more in the dry weight of an organism. C, H, O, N, P, S, Ca, K, Mg are found as macro elements in all organisms. In some organisms e.g. Human Na, Fe and Cl are also found as macro molecules. Trace elements Found less than 0.01% in dry weight Cl, Si, V, Cr, Co, B, Mn, Zn, Cu, Mo,I,Fe,Al etc. Functions of macro elements and trace elements Competency 2.1.0 : Investigates the chemical basis of life. Competency Level 2.1.2 : Investigates the physical and chemical properties of water important for life. Number of Periods : 02 Learning Outcomes : The Student should be able to:explain the importance of water for life.
Describe physical and chemical properties of water which are important for life. Relate the physical and chemical properties of water to its functions performed in living systems.
Guidelines : Importance of water for life. The most abundant inorganic compound in living matter is water. The main functions of water in organisms. 1. Component of protoplasm 2. Solvent 3. Reactant 4. Maintaining turgidity Other functions-Refer the note.
Chandi Palawela. Royal College B.Sc. (Hons -First Class); PG.Dip.in Edu Tel: 0718 617591
2
Competency 2.1.0 : Investigates the chemical basis of life. Competency Level 2.1.3 : Examines the chemical nature and functions of main organic compounds of organisms. Number of Periods : 08 Learning Outcomes : The student should be able to :describe the basic chemical nature of four main types of organic compounds found in organisms Elaborate on the functions of four major types of organic compounds. Conduct laboratory tests to identify the reducing sugars, non reducing sugars, starch, proteins and Lipids. Guidelines: Describe the basic chemical nature and functions of the four main types of organic compounds found in organisms The major organic compounds found in organisms are-Carbohydrates, Lipids, Proteins Nucleic acids Explain that carbohydrates, proteins, lipids and nucleic acids are found in living matter, and are considered as major biological molecules. State that large molecules (molecular weight 104 - 1010) such as proteins, nucleic acids and some carbohydrates are considered as macromolecules. Carbohydrates Most abundant organic matter on earth
The substances that we know as sugars and flour in day-to-day life are examples
Major elemental composition is C,H,O
General formula Cx(H2O)y - Hydrates of carbon contains the same proportions of H:O (2:1) found in
water
Monosaccharide, disaccharides and polysaccharides are the three main classes of carbohydrates
Monosaccharide
Explain the basic chemical nature and biological functions.
Name monosaccharide according to the number of C atoms as; Triose (3C ) e.g. Glyceraldehydes,
Tetrose (4C) e.g. Erythrose - rare in nature, Pentose (5C) e.g. Ribose, Ribulose, Hexose (6C) e.g.
glucose, fructose, galactose. All Monosaccharides are reducing sugars
Disaccharides
Explain what glycosidic bonds are and how two monosaccharides form disaccharides.
E.g., 2C6H12O6 C12H22O11 + H2O
Maltose, Lactose are reducing sugars, Sucrose is not a reducing sugar.
Chandi Palawela. Royal College B.Sc. (Hons -First Class); PG.Dip.in Edu Tel: 0718 617591
3
Polysaccharides
Explain how polymeric structure is formed. Straight chains and branched chain structure. Basic
structure and functions of starch, glycogen and cellulose. Amylase activity on starch. Inulin as an
example of another polysaccharide and hemicelluloses, pectin and chitin as important polysaccharide
derivatives.
Functions of Carbohydrates
Explain the importance and functions of monosaccharide, disaccharides and polysaccharides in cellular
function.
Demonstrate some simple laboratory tests to identify starch, reducing and non reducing sugars and to
observe hydrolysis of starch by amylase.
Lipids
Brief description of following points Heterogeneous group of compounds which are insoluble in
water.Major elemental composition is C,H,O sometimes P and/or N. Less oxygen than carbohydrates
The structure of fatty acids - saturated and unsaturated with examples. Distinguish oils and fats.
Triglyceride structure of oils and fats. Give examples of other types of lipids e.g., waxes,
phospholipids, steroids and terpenes.
Explain major functions of lipids.
Laboratory tests to identify fats and oils.
Proteins
State proteins are polymers of amino acids with high molecular weights. They contain C, H,O, N and
sometimes S State amino acids as monomer units of proteins. Although there are several amino acids
in the body only around 20 different amino acids are involved in making proteins.
Explain what are peptide bonds, how they are formed and Polypeptide structure. Complex structure of
proteins can be described in 4 stages. Primary - linear sequence of amino acids. Secondary - helical or
pleated sheet structure Tertiary - bending, folding of polypeptide chains produce globular shape.
Different types of bonds stabilizing tertiary structure.
Quaternary- aggregation of 2 or more polypeptides to form a complex globular structure.
Denaturation of proteins, effect of denaturation on activity of protein.
Role of proteins in cells and organisms. Explain different types of functions
Chandi Palawela. Royal College B.Sc. (Hons -First Class); PG.Dip.in Edu Tel: 0718 617591
9
2004
1. Which one of the following biological molecules is not a polymer? 1) RNA 2) Starch 3) ATP 4) Glycogen 5) Cellulose
3.The hydrolysis of one molecule of sucrose produces
1) Two fructose molecules 2) One glucose molecule and one fructose molecule 3) Two glucose molecules 4) One glucose molecule and one galactose molecule 5) One fructose molecule and one galactose molecule
52.Which of the following has/have mainly a structural role in living organisms?
A) Starch B) Glycogen C) Cellulose D) Phospholipid E) Acetylcholine
53.Which of the following tests is/are useful in determining the presence of protein in a sample of food?
A) Biuret test B) Millons test C) Fehling’s test D) Sudan III test E) Benedict test
2005
1. 20 Which of the following statements is incorrect regarding enzymes? 1) Enzymes are made up of amino acids 2) Enzyme reactions are reversible 3) Enzymes do no alter the natured of end products of the reactions 4) Some enzymes contain non-protein parts in their structure 5) Enzyme molecules are usually smaller than substrate molecules
Which one of the following compounds on hydrolysis will yield the above compound? 1) Starch 2) Phospholipid 3) Albumin 4) DNA 5) Glycogen
2. Which of the following statements is incorrect regarding DNA? 1) DNA of a cell, determines the structure of enzymes synthesized by the cell 2) The two strands of DNA molecule are identical 3) Genes differ from each other in the base sequences of their DNA 4) Mutations cause structural changes in the DNA molecule 5) The amount of DNA doubles before the onset of mitosis
Chandi Palawela. Royal College B.Sc. (Hons -First Class); PG.Dip.in Edu Tel: 0718 617591
10
(D) (i) Name the four major types of organic compounds that are found in living matter, indicating their elemental composition and two major functions in the following table.
Organic Compound Elemental composition Major functions
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
………………………………………………….
(ii) You are provided with three solutions. A, B and C, one of them contain amylase enzyme, and the other two contain 0.1% and 0.5% of starch solutions. If you are given the following materials, explain how you would identify the solutions containing (a) amylase solution (B) 0.5% starch solution.
Materials give : white tile, measuring cylinder, stopwatch, water, dilute iodine, test tubes in a rack, glass rods and glass tubes.