Mandatory Activities

List of Mandatory Activities

Below is a list of the mandatory activities, with links to the relevant study note

1. Conduct a qualitative test for starch, fat, a reducing sugar, a protein. Nutrition – The Chemistry of Food

2. Using simple keys. Fieldwork Ecology

3. Identify and use various apparatus required for collection methods in an ecology study. Fieldwork Ecology

4. Conduct a quantitative study of the plants and animals of a sample area of a selected ecosystem. Fieldwork Ecology

5. Investigate any three abiotic factors present in the selected ecosystem. Fieldwork Ecology

6. Be familiar with and use the light microscope. The Cell

7. Prepare and examine one animal cell unstained and stained using the light microscope. The Cell

8. Prepare and examine one plant cell unstained and stained using the light microscope. The Cell

9. Investigate the effect of pH on the rate of enzyme action. Enzymes

10. Investigate the effect of temperature on the rate of enzyme action. Enzymes

11. Investigate the effect of heat denaturation on the activity of one enzyme. Enzymes

12. Prepare one enzyme immobilisation and examine its application (higher level only) Enzymes

13. Investigate the influence of light intensity on the rate of photosynthesis. Photosynthesis

14. Prepare and show the production of alcohol by yeast. Respiration

15. Conduct any activity to demonstrate osmosis. Movement Through Cell Membranes

16. Isolate DNA from a plant tissue. DNA

17. Investigate the growth of leaf yeast using agar plates and controls. Fungi

18. Prepare and examine microscopically the transverse section of a dicotyledonous stem (x100, x400) Flowering Plant Structure

19. Dissect, display and identify sheep’s heart. Circulatory System

20. Investigate the effect of exercise on the pulse of a human. Circulatory System

21. Investigate the effect of I.A.A. growth regulator on plant tissue. Plant Growth Regulation and Responses

22. Investigate the effect of water, oxygen and temperature on germination. Seeds – dispersal and germination

23. Use starch agar plates to show the digestive activity during germination. Seeds – dispersal and germination

Department Guidelines

In the course of their studies, students should undertake a range of practical work, laboratory work and fieldwork. Students should carry out these activities over the duration of the course. A record of this work should be retained.

In all practical work safety must be a major concern. Teachers are encouraged to develop in their students positive attitudes and approaches to safety in the range of activities they encounter and to inculcate in them an awareness of the values of creating a safe working environment. Standard laboratory safety precautions should be observed and care taken when carrying out activities.

All legal and health regulations must be adhered to in activities involving live and dead organisms. Before rearing and maintaining organisms, detailed information on the appropriate methods for the rearing and maintenance of the organisms must be studied. These methods must be strictly adhered to during the activity. Students should appreciate the possibility for errors in activities and the precautions or controls that can be applied to reduce errors.

Students should also be aware that the value of scientific method is limited by the extent of our own basic knowledge, by the basis of investigation, by our ability to interpret results, by its application to the natural world (which is always subject to change or variation) and by accidental discoveries. [Extract from Department of Education and Science Leaving Certificate Biology Syllabus document]

Nutrition – The Chemistry of Food

Food is material that is a good source of one or more of the following: protein, carbohydrate or lipid.

Living organisms need food for energy, growth, repair, defence and reproduction.

Food often contains vitamins and minerals.

Metabolism

Metabolism is the full set of chemical processes carried out by a living organism (anabolism + catabolism).

Anabolism: the formation of large complex organic molecules by linking smaller simpler organic molecules. Catabolism: the breakdown of large complex molecules into smaller simpler biomolecules.

Anabolic reactions require energy input and catabolic reactions release energy.

Protein

• Elements: C, H, O and N in all proteins. Some proteins also contain P and/or S.

• Subunits: Amino acids are the subunits that are linked by peptide bonds in chains, folds and branches.

• Twenty different amino acids — each different sequence of amino acids produces a different protein.

• Each protein has a specific functional shape.

• Proteins synthesis takes place at the ribosomes.

• Meat, fish, eggs, milk, beans, peas and nuts are good sources of dietary protein.

Structural Role of Protein

• Keratin: in hair and outer layer of the skin.

• Myosin: major protein in skeletal and cardiac muscle.

Metabolic Role of Protein

• Many proteins function as enzymes (specific biological catalysts).

• Some proteins function as hormones.

Carbohydrate

• Elements: CHO. General Formula: (CH₂O)n or C_X(H₂O)_Y

• Monosaccharides: single sugar unit

• Pentoses: C₅H₁₀O₅ Deoxyribose of DNA and Ribose of RNA

• Hexoses: C₆H₁₂O₆ Glucose, Fructose, Galactose — use for respiration

• Disaccharides: double sugars — two sugar units linked together

• Maltose: glucose + glucose — intermediate between glucose and starch

• Sucrose: glucose + fructose — food transported in the phloem of plants is a sucrose solution

• Lactose: glucose + galactose — the sugar present in milk

• Polysaccharides: multisugars — the three examples are multiglucoses

• Starch: plant glucose reserve

• Glycogen: glucose reserve of animals and fungi. Glycogen stored in skeletal muscle and liver

• Cellulose: plant cells walls and fibre in our diet

Dietary Sources of Carbohydrates

• Monosaccharides: fruit, honey and jam.

• Disaccharides: Sucrose - fruit, table sugar. Lactose - milk. Maltose - germinating seeds.

• Polysaccharides: Starch: bread, rice, pasta, potatoes, seeds.

• Cellulose: fruit, vegetables, wholegrain cereals, nuts.

Structural Role of Carbohydrate

• Cellulose walls of plant cells.

• Chitin in the cell walls of fungi.

Metabolic Role of Carbohydrate

• Energy Source: energy released by the respiration of glucose is used to make ATP.

• Energy Storage: starch in plants, glycogen in animals and fungi.

Lipid

• Elements: CHO – with more H but less O than carbohydrates.

• Composed of glycerol with three fatty acids linked to the glycerol.

• Fat – solid lipid at room temperature. Oil – lipid that is liquid at room temperature.

• Phospholipid: two fatty acids and a phosphate group linked to the glycerol.

• Good Dietary Sources: meat, milk, butter, cheese, plant oils, margarine.

Structural Role of Lipid

• Lipids and Phospholipids are very important in cell membrane structure.

• The protective wax cuticle on the outside of leaves.

Metabolic Role of Lipids

• Energy storage: more than twice the energy of carbohydrate or protein.

• Energy source: released during respiration.

• Storage of fat-soluble vitamins.

• Some lipids function as hormones.

Hormones as Regulators of Metabolic Activity

• Hormones are chemical messengers that cause their target cells or tissues to adjust or alter their activity.

• Hormones stimulate or inhibit specific metabolic reactions.

• The level of stimulation or inhibition depends on the concentration of hormone in the blood.

• Hormones play an important role in homeostasis.

Vitamins

A vitamin is an organic compound needed in small quantities in the diet for health.

Water-soluble Vitamin: Vitamin C (ascorbic acid)

• Obtained in fresh fruit and vegetables.

• Needed to make and maintain connective tissue and the absorption of iron by the gut.

• Long term deficiency of vitamin C causes a disease called scurvy.

• Scurvy symptoms: internal bleeding, bruising, bleeding gums, poor healing.

Fat-soluble Vitamin: Vitamin D (calciferol)

• Obtained from milk, eggs, liver, fish liver oils and produced in skin exposed to UV light.

• It is needed for bone and tooth formation, bone maintenance and the absorption of calcium from the gut.

• Long term deficiency cause diseases known as rickets and osteomalacia.

• Major deficiency symptoms: late teething and walking, deformed legs and arms, weak bones.