TISSUES, CELLS AND MOLECULAR BIOLOGY

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1 Inorganic Compounds: Water (2H: 1O) Minerals (Na, P, I, Ca, Fe, K, nitrates, phosphates) functions and deficiencies Fertilizers Organic molecules are made up of C, H, O and some contain other elements such and N, P and S. Cells are made up of proteins, carbohydrates, lipids, nucleic acids and vitamins. Molecules for Life TISSUES, CELLS AND MOLECULAR BIOLOGY Potchefstroom High School for Bo ys Element % /degree What am I made of?

2 What is The smallest unit of matter that can take part in a chemical reaction Two or more atoms that combine with one another chemically A pure substance that is not made up of other simpler substances A pure substance made up of elements, chemically combined Name the seven basic characteristics of life: Inorganic Chemicals 2

3 Macro and Micro elements In Animals In Plants MINERAL WHERE IT IS WHY IT IS NEEDED RESULT OF MINERAL WHERE IT IS WHY IT IS RESULT OF ELEMENT FOUND DEFICIENCY ELEMENT FOUND NEEDED DEFICIENCY MACRO - MACRO - ELEMENTS ELEMENTS

4 MICRO - ELEMENTS MICRO - ELEMENTS 4

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6 Fertilizers and Eutrophication Fertilizers provide essential nutrients like nitrogen and phosphorus to the soil in which grass, vegetables and ornamental flowers grow. Large-scale farmers also use fertilizers to grow produce and other crops needed to feed a rapidly increasing population. Fertilizer nutrients left unused in soil can run off into coastal waters, lakes and streams, resulting in eutrophication, or the addition of excessive amounts of nutrients. Eutrophication can occur naturally; however, effects of human-caused eutrophication are accelerated and have serious environmental consequences. Role of Agriculture The use of manmade synthetic fertilizers has increased dramatically in recent years. Globally, nitrogen and phosphorus fertilizer use increased seven- and threefold, respectively, from 1960 to An average of 20 percent of nitrogen fertilizer is lost to leaching or surface runoff, and phosphorus enters water systems through soil erosion. When excess nutrients from fertilizers leach into rivers, lakes and estuaries, they stimulate growth of algae, just as they stimulate plant growth in gardens. This increased aquatic plant life can produce floating surface scum known as algal blooms. Impact of Eutrophication The impact of eutrophication on the environment and the economy is concerning. When algal blooms form, less sunlight can penetrate the water surface, which results in decreased productivity of underwater plants and depleted oxygen reserves. The lack of oxygen has devastating effects on aquatic life, including fish such as trout and salmon. In addition, some algae produce toxins in the water, further damaging the aquatic ecosystem. Economically, operating expenses of public water works increase as a result of taste and odor issues caused by algal bloom. Fish death and navigational impediments can impact severely the economies of regions dependent on fishing as a source of revenue. Similarly, recreational areas lose business because of slime and weed infestation around lakes and streams. Areas Affected The impact of eutrophication and the threat to water systems is widespread worldwide. Management To manage eutrophication, keep excess nitrogen and phosphorus fertilizer from reaching water systems in the first place. Before applying any fertilizer, know what nutrient levels a particular plant needs, as well as the current nutrient levels in your soil. Whenever possible, plant native and adapted plants in your garden because their water and fertilizer demands will be less than non-native plant species. Add groundcover plants to your garden to help absorb any extra nitrogen in the soil and to prevent leaching. 6

7 Chemicals used in Life Science REACTANTS PRODUCT Reactants 7

8 Indicators 8

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10 10 Organic molecules

11 Latin and Greek Number prefixes 11

12 Carbohydrates Examples Structure Composition Elements: C,H,O Ratio of H:O is 2:1 Smallest unit/building blocks are monosaccharide Two monosaccharides forms a disaccharide Many monosaccharides forms a polysaccharide Properties Monosaccharides and disaccharides o Small molecules o Soluble in water o Taste sweet Polysaccharides o Large molecules o Insoluble in water o Tastes chalky Biological Importance Primary source of energy o glucose Can be stored o Starch (plants) o Glycogen (animals) Structural/strengthening/ supportive o Cellulose (plants cell walls) Influence osmotic potential o Mono- & disaccharides Practical 1.1: Glucose test AIM: To develop a reference test for a reducing sugar, e.g. glucose APPARATUS WATER BATH SPATULA/TEASPOON TEST TUBES BEAKER BENEDICT S SOLUTION OR FEHLINGS A & B DROPPER METHOD 1. Set up three test tubes in a glass beaker 2. Mark each of the test tubes in a different color (e.g. black, red, blue), as 1, 2 and 3 3. Make up three different solutions (or your teacher will supply you with these) a. Solution A Glucose b. Solution B Sucrose c. Solution C - Starch 4. Add equal amounts of each solution to separate test tubes: a. Solution A to test tube 1 b. Solution B to test tube 2 c. Solution C to test tube 3 5. Add 5 drops of Benedicts solution (of 5 drops Fehlings A and 5 drops Fehlings B) to each test tube 6. Observe the colour while the test tubes are cold 7. Add boiling water to the glass beaker and place the test tubes inside the glass beaker/ boil water over a bunsen burner 8. Observe the colour while the test tubes are warm 12

13 EXPERIMENTAL DESIGN: INDEPENDENT VARIABLE: DEPENDENT VARIABLE FIXED VARIABLES: APPARATUS: ORGANISMS: ENVIRONMENT: RESULTS Solution Colour before heating with indicator Colour after heating with indicator A Glucose B Sucrose C Starch 13

14 Practical 1.2: Starch test AIM: To develop a reference test for starch APPARATUS METHOD SPATULA/TEASPOON TEST TUBES BEAKERS INDICATOR: IODINE DROPPER 1. Set up three test tubes in a glass beaker 2. Mark each of the test tubes in a different color (e.g. black, red, blue), as 1, 2 and 3 3. Make up three different solutions (or your teacher will supply you with these) a. Solution A Glucose b. Solution B Sucrose c. Solution C - Starch 4. Add equal amounts of each solution to separate test tubes: a. Solution A to test tube 1 b. Solution B to test tube 2 c. Solution C to test tube 3 5. Add 5 drops of Iodine 6. Observe the colour while the test tubes are cold EXPERIMENTAL DESIGN: INDEPENDENT VARIABLE: DEPENDENT VARIABLE FIXED VARIABLES: APPARATUS: ORGANISMS: ENVIRONMENT: 14

15 RESULTS Solution A Glucose Colour with indicator B Sucrose C Starch HOMEWORK QUESTIONS DATE: 1. Mark the following statements as TRUE or FALSE: a. Sucrose is the same thing as table sugar. b. The body is able to digest fiber and convert it to a sugar called glucose c. The brain uses glucose as its main source of energy. d. Starch is made up of glucose units linked together (4) 2. What is lactose intolerance? (2) 3. Define the term empty-calorie food and list three examples: (5) 4. List two benefits of eating lots of fiber: (2) 5. What do you understand by the term reducing sugar? (2) TOTAL: 15 15

16 Proteins Structure Dehydration synthesis Composition Properties Elements: C,H,O,N, S,P,Fe Large molecules Building blocks/monomers is amino acids High temperature can denature them 20 different amino acids in the body Low temperatures inactivates them Two amino acids together is a dipeptide Extreme ph denatures them A chain of amino acids is a polypeptide Peptide bonds Biological Importance & Examples Fibrous Proteins Globular Proteins 16

17 Practical 1.3 AIM: To develop a reference test for proteins APPARATUS METHOD WATER BATH SPATULA/TEASPOON TEST TUBES BEAKER MILLONS REAGENT BUIRET SOLUTION DROPPER EXPERIMENTAL DESIGN: INDEPENDENT VARIABLE: DEPENDENT VARIABLE 1. Set up four test tubes in a glass beaker 2. Mark each of the test tubes as 1, 2, 3 and 4 3. Make up two different solutions (or your teacher will supply you with these) a. Solution A Albumin (egg white) b. Solution B Sucrose (any non-protein solution) 4. Add equal amounts of each solution to separate test tubes: a. Solution A to test tube 1 and 2 b. Solution B to test tube 3 and 4 5. Add 5 drops of Millons reagent to test tube 1 and 3 6. Add 5 drops of Buiret solution to test tube 2 and 4 7. Observe the colour while the test tubes are cold 8. Add boiling water to the glass beaker and place the test tubes inside the glass beaker/ boil water over a 17unsen burner 9. Observe the colour while the test tubes are warm FIXED VARIABLES: APPARATUS: ORGANISMS: ENVIRONMENT: 17

18 RESULTS MILLONS REAGENT Solution Colour before heating with indicator Colour after heating with indicator A B BUIRET SOLUTION Solution Colour before heating with indicator Colour after heating with indicator A B Enzymes Definition: Enzymes are: Lock-and-Key mechanism 18

19 THE EFFECT OF AN ENZYME ON THE RATE OF A CHEMICAL REACTION THE EFFECT OF TEMPERATURE ON THE ACTIVITY OF AN ENZYME THE EFFECT OF PH ON THE ACTIVITY OF AN ENZYME Enzyme Substrate Enzyme Product 19

20 Practical 1.4 AIM: To investigate the effect of temperature on the activity of an enzyme APPARATUS WATER BATH SPATULA/TEASPOON TEST TUBES BEAKER HCL( DILUTED) DROPPER PEPSIN SOLUTION THERMOMETER METHOD 1. Set up three test tubes each in its own glass beaker 2. Mark each of the test tubes as 1, 2, and 3 3. Make up a solutions (or your teacher will supply you with these) of Solution A Albumin (egg white) 4. Add equal amounts of the solution to each test tubes 5. Add 3 drops HCl to each test tube 6. Add 3 drops pepsin to each test tube 7. Immediately place the test tubes in different conditions a. Test tube 1 in water with ice in a beaker b. Test tube 2 in water from the tap in a beaker c. Test tube 3 in boiling water in a beaker 8. Allow the test tubes to stand for 20 minutes 9. Observe the content of the test tube EXPERIMENTAL DESIGN: INDEPENDENT VARIABLE: DEPENDENT VARIABLE FIXED VARIABLES: APPARATUS: ORGANISMS: ENVIRONMENT: RESULTS Test tube 1 Test tube 2 Test tube 3 20

21 HOMEWORK QUESTIONS DATE: Catalase is an enzyme. It catalyses the following reaction: 1. How much oxygen was produced between 120 and 130 seconds? (1) 2. Less oxygen was produced between 80 and 90 seconds than between 10 and 20 seconds. Use your knowledge of the way enzymes work to explain why. (2) 3. Sketch a curve on the graph to show how the rate of reaction changed over the time shown (2) 4. Describe how you could test the catalase preparation to show that it contains protein. (2) 5. When scientists measure the activity of an enzyme, they make sure that the enzyme is at its optimum ph. Explain why. (2) TOTAL:9 21

22 Nucleotides Examples Structure Composition Monomer is a nucleotide Nucleotide consists of: o Phosphate o Pentose sugar o Nitrogenous bases: Adenine Guanine Cytosine Thymine Properties Twisted ladder form Double helix Held together with hydrogen bonds between bases Biological Importance Stores genetic information Determines the structure and function of cells 22

23 Lipids Examples Structure Composition Elements : C,H,O Ratio of H:O is greater than 2:1 Composed of one o glycerol molecule o three fatty acid o ester bonds Properties Insoluble in water Soluble in ether Biological Importance Superior source of energy Stored as reserve energy by plants and animals Fat under skin is an insulator Fat between organs is a shock absorber Phospholipids are structural components of cell membranes Practical 1.5: Test for the presence of lipids AIM: To develop a reference test for lipids/fats APPARATUS ETHER/ETHANOL FILTER PAPER/BROWN PAPER COOKING OIL DROPPER METHOD 1. Add a few drops of oil to 20 ml ether/ethanol and agitate until oil dissolves 2. Using a dropper place one drop of the mixture onto a filter paper/brown paper 3. Draw a circle in pencil around the moist patch 4. Allow the filter paper to dry 5. Observe the filter paper when the ether/ethanol has evaporated EXPERIMENTAL DESIGN: INDEPENDENT VARIABLE: DEPENDENT VARIABLE FIXED VARIABLES: APPARATUS: ORGANISMS: ENVIRONMENT: 23

24 RESULTS 24