Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 60 CHAPTER 4 Chemical Composition In A Cell “Dan dari air, Kami jadikan segala sesuatu yang hidup” Surah Al-Anbiya: Ayat 30
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 61 4.1 WATER Polarity Of Water 1. Inorganic compound consisting of the hydrogen (H) and oxygen (O) elements. 2. Polar molecules because shared electrons between oxygen and hydrogen 3. Attracted towards oxygen which is more electronegative (δ–). 4. This polarity produces hydrogen bonds and allows water to act as a universal solvent 5. The universal solvent properties of water allow solutes such as glucose and electrolytes to be transported through the plasma membranes into cells for biochemical reactions. Water molecule Salt crystal Cohesive Force And Adhesive Force Of Water 1. Capillary action allows water enter and move along narrow spaces, such as in the xylem tube. 2. Consist of two forces Cohesive force Adhesive force + Chloride Sodium
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 62 Specific Heat Capacity Of Water 1. Specific heat capacity refer to heat energy is required to raise the temperature of one kilogram of water by 1°C 2. Water has a high of 4.2 kJ kg-1 °C-1 . 3. Water absorbs a lot of heat energy with a small rise in temperature. 4. Essential to maintain the body temperature of organisms. Balloon burst Balloon not burst Water molecule Adhesive force • Water molecules are attached to other surfaces Cohesive force • Water molecules are attached to each other • By hydrogen bond Xylem wall Y Z Balloon Water Candle
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 63 COMPOUND 1. A compound is substance which consist of two or more elements combined in a fixed ratio 2. Large and complex compounds form macromolecules. 3. Most macromolecules are polymers comprising small molecules known as monomers (building blocks) 4. Compounds are divided into two types; 4.2 CARBOHYDRATES 1. Carbohydrates are important as a source of energy 2. Also, basic structure of some organisms. Chitin – Form exoskeleton of insect Cellulose – Form cell wall in plant cell 3. Carbohydrates consisting of the elements carbon (C), hydrogen (H) and oxygen (O) in the ratio 1:2:1 4. With the chemical formula (CH2O)n. Inorganic compound Chemical compounds that not contain carbon element Examples Water Acid Base Salt Compound Organic compound Chemical compounds that contain carbon element Examples Carbohydrate Protein Lipid Nucleic acid Tree map CH2O = C6H12O6 (Glucose)
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 64 Types Of Carbohydrates Monosaccharides 1. Can combine to form polymers through a condensation process. 2. Most monosaccharides taste sweet, can form crystals and dissolve in water. 3. Examples; Monosaccharide Source Glucose Rice, wheat and fruit Fructose Honey and sweet fruit Galactose Milk 4. All monosaccharides are reducing sugars because it will reduce the blue copper (II) sulphate to a brick red precipitate of copper (I) oxide Carbohydrate Monosaccharide (Simple sugar) Glucose Fructose Galactose Disaccharide Maltose lactose sucrose Polysaccharide (Complex sugar) Cellulose Starch Glycogen Tree map monosaccharides Condensation monosaccharides + + Water Disaccharide Covalent bond
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 65 Disaccharides 1. Formed when two simple sugar molecules (monosaccharides) combine through condensation to form a disaccharide unit. 2. Condensation is process of a covalent bond is formed between two molecules of monosaccharides 3. Involves the removal or production of water molecule Glucose + Glucose Maltose + Water Glucose + Fructose Sucrose + Water Glucose + Galactose Lactose + Water 4. Disaccharides can also be broken down to their monosaccharide units through hydrolysis 5. Hydrolysis is a process the covalent bond between two molecules of monosaccharides is broken down 6. Involves the addition or using of water molecule Maltose + Water Glucose + Glucose Sucrose + Water Glucose + Fructose Lactose + Water Glucose + Galactose 7. Lactose and maltose are reducing sugars while sucrose is a non-reducing sugar Condensation Condensation Condensation Hydrolysis Hydrolysis Hydrolysis
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 66 Polysaccharides 1. Sugar polymers consisting of monosaccharide monomers. 2. Formed through the condensation process 3. Involves hundreds of monosaccharides to form long molecular chains. 4. Polysaccharides are not soluble in water due to their large molecular size. 5. Polysaccharides neither taste sweet nor crystallise. Starch Glycogen Cellulose The main storage of polysaccharide in plants The main storage of polysaccharide found in muscle cells and animal liver cells Forms the main structure of the plant cell wall 6. Polysaccharides can also disintegrate through hydrolysis with the help of dilute acids, boiling and enzyme action. Polysaccharide (Starch) + Water Hydrolysis (Amylase) Disaccharide (Maltose) Brace map Source of energy Importance of carbohydrates in cells Glucose Support structure Food reserve Cellulose in the plant cell wall Starch in plant cells Glycogen in animal cells
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 67 4.3 PROTEIN 1. Complex compound composed of carbon, hydrogen, oxygen and nitrogen elements. 2. Most proteins also contain sulphur and phosphorus. 3. All proteins are composed of one or more polymers known as polypeptides. 4. Each polypeptide is made up of monomers or small units known as amino acids. 5. Amino acids are linked together through the condensation process. 6. Dipeptides are composed of two amino acid molecules which are linked together 7. By a peptide bond through the condensation process which one water molecule is removed. 8. Further condensation can link more amino acids to form a polypeptide chain. Amino acid + Amino acid Dipeptide + Water 9. Dipeptide can be broken down into an amino acid through hydrolysis. Dipeptide + Water Amino acid + Amino acid Importance Of Proteins In A Cell Condensation Hydrolysis Tree map Build new cells Repair damaged tissues Form building blocks Synthesis of protein Such as Enzymes Hormones Antibodies Haemoglobin Such as Keratin Myosin Collagen In skin and hair In muscle tissues In bones
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 68 4.4 LIPIDS 1. Lipids are hydrophobic compounds found in plant and animal tissues. 2. Made up of carbon, hydrogen and oxygen elements 3. Much higher ratio of hydrogen atoms to oxygen atoms compare to carbohydrate 4. Lipids are insoluble in water but soluble in other organic solvents 5. Example are alcohol, ether and chloroform. Types Of Lipids Brace map Fat Lipid Wax Cholesterol Hormone Phospholipid Steroid Triglyceride Cuticle Sebum Prevent evaporation of water in plant leaf Soften the skin Testosteron Oestrogen Progesteron Source of energy Major component of plasma membranes Heat insulator
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 69 Fats 1. Fats and oils are triglycerides 2. Triglycerides are a type of ester formed from the condensation reaction 3. One molecule of glycerol combines with three molecules of fatty acid 4. Covalent bonds are formed between the molecules 5. With the producing of three water molecules 6. Triglycerides can be hydrolysed again into fatty acids and glycerol 7. Through the reaction of hydrolysis. 8. Covalent bonds are breakdown between the molecules 9. With the using of three water molecules 10. To produce one molecule of glycerol and three molecules of fatty acids 11. There are two types of fatty acids; Saturated fatty acids Unsaturated fatty acids. Comparison Between Saturated Fatty Acids And Unsaturated Fatty Acids Similarities 1. Both consist of carbon, hydrogen and oxygen elements. 2. Both contain glycerol and fatty acids. 3. Both contain nonpolar molecules Hydrolysis Condensation Glycerol Fatty acid Water + + 3H2O Triglyceride
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 70 Differences Example of food Type of fat Saturated fat Unsaturated fat Type of bond Only have single bonds between carbon Have at least one double bond between carbon. Boiling point High boiling point Low boiling point Condition in room temperature Solid form Liquid form Cholesterol content High cholesterol content Low cholesterol content Source of fat Butter and animal fat Olive and fish oil
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 71 4.5 NUCLEIC ACIDS 1. Nucleic acids are one or two polymer chains comprising of nucleotide monomers. 2. Formed from the elements of carbon, hydrogen, oxygen, nitrogen and phosphorus. 3. Each nucleotide consists of a pentose sugar (5-carbon sugar), a nitrogenous base and a phosphate 4. Combined together through the condensation process Nucleotide structure 5. There are two types of pentose sugars, that are, Ribose Deoxyribose. 6. The nitrogenous base consists of Adenine (A) guanine (G), cytosine (C), thymine (T) and Uracil (U) Deoxyribonucleic acid (DNA) 1. DNA consists of two polynucleotide chains that are intertwined in opposite directions and form the double helix 2. The nitrogenous base groups on both polynucleotide chains are matched and bound together by hydrogen bonds. 3. The nitrogenous bases for DNA are adenine (A), guanine (G), thymine (T) and cytosine (C). 4. Adenine will pair with thymine while guanine will pair with cytosine A B C Phosphate group Pentose sugar Nitrogenous base
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 72 Ribonucleic acid (RNA) 1. The RNA structure is a single polynucleotide chain which is shorter compared to DNA 2. The nitrogenous bases for RNA are adenine, guanine, cytosine and uracil. 3. Thymine in DNA is replaced by uracil in RNA. 4. The three main types of RNA; Messenger RNA (mRNA) Ribosomal RNA (rRNA) Transfer RNA (tRNA). 5. These three RNAs are involved in the process synthesis of protein.
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 73 Importance Of Nucleic Acids In A Cell Synthesis of Protein Tree map Carrier of hereditary information Contains genetic codes carried by nitrogenous base To determinant of characteristics in living organisms For the synthesis of polypeptides 1 DNA strand unwind DNA is transcribed into mRNA codons 2 Serene Transcription Codon is the three-base sequence of nucleotides 3 Codon Codon Codon Codon is translated into the amino acid sequence to form a single polypeptide chain Translation 4 Polypeptide chain Lysine Valine mRNA
Sirrun Najaah Fi Ilmi Al Insan Chapter 4: Chemical Composition In A Cell 74 Formation Of Chromosomes From DNA And Proteins 1 DNA polynucleotide chains that are wound around a protein called histone 2 DNA molecules combine with histone proteins to form nucleosomes 3 Nucleosomes are intertwined to form the chromosome structure DNA Histone Nucleosome Chromosome Cell