DIGESTIVE SYSTEM JSS2 WEEK 2 SECOND TERM
WEEK: TWO DATE: ________ CLASS: JSS2
SUBJECT: BASIC SCIENCE
LESSON TITLE: Digestive system
SUBTITLE (IF ANY):
PERIOD: DOUBLE DURATION: _______
LEARNING OBJECTIVES: By the end of the lesson, students should be able to
- Mention Part of Alimentary Canal
- Difference between permanent teeth and milk teeth
- Reagent To Test For Food Items
- Characteristic Of An Enzymes
DIGESTIVE SYSTEM JSS2 WEEK 2 SECOND TERM
KEY VOCABULARY WORDS:
Complex Network, organs, Alimentary Canal,Esophagus,Pancreas: Timing of Eruption:
RESOURCES & MATERIALS:
BUILDING BACKGROUND/CONNECTION TO PRIOR KNOWLEDGE: The student are familiar with feeding in living things and respiratory system
CONTENT: The digestive system is a complex network of organs and structures that work together to process the food we eat, extract nutrients, and eliminate waste. Its primary function is to break down ingested food into smaller, absorbable components that can be used by the body for energy, growth, and repair.
The main organs of the digestive system include:Part of Alimentary Canal
Mouth: The process of digestion begins in the mouth, where food is chewed and mixed with saliva, which contains enzymes that start breaking down carbohydrates.
Esophagus: The esophagus is a muscular tube that connects the mouth to the stomach. It allows the passage of chewed food from the mouth to the stomach through a process called swallowing.
Stomach: In the stomach, food is mixed with gastric juices, which contain acids and enzymes that further break down the food into a semi-liquid substance called chyme.
Small Intestine: The majority of digestion and nutrient absorption occur in the small intestine. Enzymes from the pancreas and bile from the liver aid in breaking down fats, proteins, and carbohydrates. Nutrients are then absorbed through the lining of the small intestine into the bloodstream.
Liver: The liver produces bile, which is stored in the gallbladder and released into the small intestine to help emulsify fats, making them easier to digest.
Pancreas: The pancreas secretes digestive enzymes into the small intestine to further break down carbohydrates, proteins, and fats.
Large Intestine (Colon): The remaining undigested food and water move into the large intestine, where water and electrolytes are absorbed, and the remaining material is formed into feces.
Rectum: The rectum stores feces until they are ready to be eliminated.
Anus: The anus is the opening through which feces are expelled from the body during the process of defecation.
Difference Between Permanent Teeth And Milk Teeth
The primary difference between permanent teeth and milk teeth, also known as baby teeth or deciduous teeth, lies in their timing, function, and the number of teeth in each set. Here are the key distinctions:
Timing of Eruption:
Milk Teeth: Baby teeth usually begin to emerge between 6 and 12 months of age, and the full set of 20 milk teeth is typically in place by the age of 3.
Permanent Teeth: Permanent teeth start to replace baby teeth around the age of 6 and continue until the late teens or early twenties. The complete set of permanent teeth includes 32 teeth.
Function:
Milk Teeth: Baby teeth play a crucial role in the early stages of life, helping infants chew soft foods and aiding in speech development.
Permanent Teeth: Permanent teeth are designed to last throughout adulthood and are responsible for chewing a wider variety of foods. They also contribute to facial structure and support overall oral health.
Number:
Milk Teeth: There are 20 milk teeth in total—10 in the upper jaw and 10 in the lower jaw. Each quadrant (half of the upper or lower jaw) has 2 incisors, 1 canine, and 2 molars.
Permanent Teeth: The complete set of permanent teeth consists of 32 teeth. Each quadrant has 2 incisors, 1 canine, 2 premolars, and 3 molars.
Replacement:
Milk Teeth: Baby teeth eventually fall out as part of a natural process known as exfoliation. This typically occurs as permanent teeth push through the gums and replace the baby teeth.
Permanent Teeth: Permanent teeth are intended to last a lifetime, and there are no natural replacements for them. However, issues such as tooth decay or injury can lead to the loss of permanent teeth.
Composition:
Milk Teeth: Baby teeth have thinner enamel compared to permanent teeth, making them more susceptible to decay.
Permanent Teeth: Permanent teeth have thicker enamel, which provides greater protection against decay and wear.
Understanding the differences between milk teeth and permanent teeth is essential for parents and caregivers to promote good oral hygiene habits in children and to monitor the development of a healthy adult dentition. Regular dental check-ups and proper oral care play crucial roles in maintaining the health of both sets of teeth.
Reagent To Test For Food Items
Testing for specific food items often involves using reagents that react with certain compounds or substances present in those foods. Here are some common food tests and the reagents associated with them:
Starch Test:
Reagent: Iodine solution (Iodine-potassium iodide solution)
Procedure: Add a few drops of iodine solution to the sample. A blue-black color indicates the presence of starch.
Protein Test:
Reagent: Biuret reagent
Procedure: Add a few drops of Biuret reagent to the sample. A violet or purple color indicates the presence of proteins.
Reducing Sugar Test:
Reagent: Benedict’s solution (copper(II) sulfate solution with sodium citrate)
Procedure: Mix the sample with Benedict’s solution and heat the mixture. A color change (from blue to green, yellow, orange, or red) indicates the presence of reducing sugars.
Lipid (Fat) Test:
Reagent: Sudan III or Sudan IV stain
Procedure: Mix the sample with Sudan III or Sudan IV stain. The appearance of a red-stained layer or droplets indicates the presence of lipids.
Vitamin C (Ascorbic Acid) Test:
Reagent: DCPIP (2,6-dichlorophenolindophenol) solution
Procedure: Add DCPIP solution to the sample. A blue color indicates the presence of vitamin C, as it acts as a reducing agent and decolorizes DCPIP.
Glucose Test:
Reagent: Benedict’s solution or Fehling’s solution
Procedure: Mix the sample with the reagent and heat. A color change (from blue to green, yellow, orange, or red) indicates the presence of glucose.
Iodine Test for Lipids (not commonly used):
Reagent: Iodine solution
Procedure: Dissolve the sample in ethanol and then add a few drops of iodine solution. A yellow or brown color indicates the presence of lipids.
DIGESTIVE SYSTEM JSS2 WEEK 2 SECOND TERM
It’s important to note that these tests are qualitative and may not provide precise quantitative measurements. Additionally, some tests may be specific to certain components within a food item. Proper safety precautions and adherence to testing protocols should be followed when conducting these tests.
Characteristic Of An Enzymes
Enzymes are biological molecules that act as catalysts, facilitating and accelerating biochemical reactions within living organisms. They play crucial roles in various physiological processes. Here are some key characteristics of enzymes:
Catalytic Activity:
Enzymes are highly efficient catalysts, speeding up chemical reactions without being consumed or permanently altered in the process.
Specificity:
Enzymes exhibit specificity for their substrates, meaning they typically catalyze a particular reaction or a group of closely related reactions. The active site of an enzyme is complementary in shape and charge to its specific substrate.
Substrate Binding:
Enzymes bind to specific substrates through non-covalent interactions, forming an enzyme-substrate complex. The active site of the enzyme is the region where the substrate binds.
Lock and Key Model:
The lock and key model describes the specificity of enzyme-substrate binding, where the active site of the enzyme is like a lock, and the substrate is the key that fits into the lock.
Induced Fit Model:
The induced fit model suggests that the active site of the enzyme undergoes conformational changes upon substrate binding, creating a more optimal fit for the substrate.
Temperature Sensitivity:
Enzymes have an optimal temperature at which they function most efficiently. Deviations from this temperature can affect enzyme activity. Extreme temperatures (too high or too low) can denature enzymes.
pH Sensitivity:
Enzymes have an optimal pH at which they function best. Changes in pH outside this range can alter the enzyme’s shape and affect its activity. Different enzymes may have different pH optima.
Cofactors and Coenzymes:
Enzymes may require additional non-protein molecules called cofactors or coenzymes to function properly. These molecules can be ions, vitamins, or small organic molecules.
Reversibility:
Enzymes can catalyze reversible reactions, meaning they can facilitate the conversion of substrates into products and, under different conditions, facilitate the conversion of products back into substrates.
Enzyme Inhibition:
Enzyme activity can be regulated through inhibition. Inhibitors can be reversible or irreversible and may compete with substrates for the active site or bind to other parts of the enzyme.
Enzyme Regulation:
Enzyme activity is often regulated by factors such as feedback inhibition, where the end product of a metabolic pathway inhibits an enzyme involved in its synthesis.
DIGESTIVE SYSTEM JSS2 WEEK 2 SECOND TERM
STRATEGIES & ACTIVITIES:
- Mention Part of Alimentary Canal
- Difference between permanent teeth and milk teeth
- Reagent To Test For Food Items
- Characteristic Of An Enzymes
ASSESSMENT (EVALUATION): The teacher ask question based on the learning objectives at the end of the class.
- Mention Part of Alimentary Canal
- Difference between permanent teeth and milk teeth
- Reagent To Test For Food Items
- Characteristic Of An Enzymes
WRAP-UP (CONCLUSION): The teacher concludes by revise the topic again and the key words was emphasized.
ASSIGNMENT:
Mention Part of Alimentary Canal And Draw The Diagram
The digestive system plays a crucial role in maintaining the body’s energy balance and providing the necessary nutrients for various physiological functions. It is a coordinated and intricate system that ensures the proper breakdown of food and absorption of nutrients while eliminating waste.
DIGESTIVE SYSTEM JSS2 WEEK 2 SECOND TERM
