CHEMICAL SUBSTANCES OF THE CELL
Organism
System
Organ
Tissue
Elements
Cell
Learning outcome
State the elements of the cell
List chemical compounds in the cell
Explain the importance of organic compounds in the cell
Explain the importance of water in the cell
= CHON
Refer to figure 4.1 and table 4.1 (page 58)
Chemical reaction
Elements
Chemical compound
Organic compound
Contain the element of carbonConsist of:Carbohydrates
Proteins
Lipids
Nucleic acid
Inorganic compound
Do not contain the element of carbonEg: water2.Protein
Energy store
Structure & shape
Movement
Defense
Enzyme
Blood coagulation
Hormones
3. Lipid
Fats & oilsInsulate heatProtect organEnergy storePhospholipid control cell permeabilityWaxesPrevent water loss
Waterproof
Makes plasma membrane rigid and stable
4. Nucleic acid
What is nucleic acid?
Complex macromolecules that store genetic information in the form of a code.
Building blocks: nucleotides (consist of a nitrogenous base, a phosphate group and a pentose sugar)
2 types:
Deoxyribonucleic acid (DNA)
Double helix structure
Can be found in nucleus, chloroplast and mitochondria
Contains genetic information that will be passed from parent to the offspring
Refer to Figure 4.3 (page 60)
Ribonucleic acid (RNA)
Single strand of nucleotides
Found in cytoplasm, ribosomes and nucleus
Genetic materials for some viruses
Copies information carried by DNA for use in protein synthesis
The importance of nucleic acid
Store genetic information
Stable storage
Easy to duplicate for transmission
Transmission of genetic information
Solvent
- polar molecule (unequal distribution of charge)
- attract one another as well as ions
Transport medium
- transport dissolved substances inside and outside the cell
Medium for biochemical reactions
- eg: breaking down of proteins, lipids and sugars
Maintaining a stable internal environment
Lubrication
- eg: mucus (composed mostly of water) assist the movement of food substances in the intestinal tract.
High cohesion
- tend to stick each other and move in long unbroken column through vascular tissues in plants
Learning outcome:
At the end of the lesson, you should be able to:
State the elements of carbohydrates
State the types of carbohydrates
Explain the formation and breakdown of disaccharides and polysaccharides
Monosaccharide
Disaccharides
Polysaccharides
Protein glycoprotein
Phospholipid glycolipid
Example: Glucose (plants and fruits)Fructose (sweet fruits and honey)Galactose (milk)monosaccharides are reducing sugarProcess removal of water molecules when bond is formed between two monosaccharides
Monosaccharide + monosaccharide
Hydrolysis
Condensation
Disaccharide + water
condensation
Maltose and lactose are reducing sugar while sucrose notHydrolysis
Monosaccharides(+ H2O) Disaccharide (- H2O)Source Glucose + glucoseMaltose Malt Glucose + fructoseSucrose Cane Glucose + galactoseLactose Milkstarch (reserved in plant);
Glycogen (animal and human); and
Cellulose (made up cell wall)
Many monosaccharide join together in a condensation reaction
This reaction called as polymerisation
In polymerisation, individual monosaccharide called as monomer
Result:
Animal = glycogenPlant = cellulose and starch- form group of 3 person; and
- Focus practice 4.2
Submission date: 2nd March 2010
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