give me the repeated questions and answers in Digestive system and enzymes through the last 5 years in edexcel grade 10 IGCSE
I don’t have access to specific exam papers or their repeated questions, but I can certainly summarize common topics and typical questions that may appear in Edexcel IGCSE Science exams concerning the digestive system and enzymes based on general trends from the syllabus. Here are some frequently covered topics along with example questions and their answers:
### Common Topics in Digestive System and Enzymes:
1. **Structure and Function of the Digestive System**
- Organs involved (mouth, esophagus, stomach, intestines, liver, pancreas).
- Main functions (digestion, absorption).
2. **Digestive Process**
- Mechanical and chemical digestion.
- Importance of enzymes in digestion.
3. **Enzymes**
- Enzyme structure and function.
- Factors affecting enzyme activity (temperature, pH).
- Role of specific enzymes (amylase, protease, lipase).
4. **Absorption**
- How nutrients are absorbed in the small intestine.
- The role of villi and microvilli in absorption.
5. **Health and Diet**
- Effects of a poor diet on digestion.
- Disorders related to the digestive system (e.g., lactose intolerance, obesity).
### Example Questions and Answers
1. **Question: Describe the function of the enzyme amylase in digestion.**
- **Answer:** Amylase is an enzyme that catalyzes the breakdown of starch into sugars (maltose and glucose) during the process of digestion. It is produced in the saliva (salivary amylase) and by the pancreas (pancreatic amylase) and acts primarily in the mouth and small intestine.
2. **Question: What are the main components of the digestive system, and briefly explain the function of each.**
- **Answer:**
- **Mouth:** Begins digestion with mechanical breakdown and salivary amylase.
- **Esophagus:** Transports food to the stomach through peristalsis.
- **Stomach:** Mixes food with gastric juices; enzymes and acid begin protein digestion.
- **Small Intestine:** Major site for digestion and absorption of nutrients.
- **Large Intestine:** Absorbs water and electrolytes; compacts waste.
- **Liver:** Produces bile for fat emulsification.
- **Pancreas:** Produces digestive enzymes and bicarbonate.
3. **Question: Explain how temperature and pH affect enzyme activity.**
- **Answer:** Enzymes have an optimal temperature and pH at which they function best. Increasing temperature generally increases enzyme activity until it reaches the enzyme's denaturation point, beyond which the activity sharply drops. Similarly, each enzyme has an optimal pH range; deviation from this can alter the enzyme's shape and reduce its activity.
4. **Question: What role do villi play in the digestive system?**
- **Answer:** Villi are small, finger-like projections lining the wall of the small intestine. They increase the surface area for absorption of nutrients into the bloodstream. Each villus contains microvilli, which further enhance the absorptive surface.
5. **Question: How can a deficiency in certain nutrients affect digestion and health?**
- **Answer:** A deficiency in nutrients, such as fiber, can lead to digestive issues like constipation. A lack of enzymes (e.g., lactase) can cause lactose intolerance, resulting in digestive discomfort when consuming dairy products. Overall, nutrient deficiencies can impair overall health, growth, and energy levels.
### Tips for Studying:
- Review past Edexcel exam questions related to the digestive system and enzymes.
- Understand the processes rather than just memorizing facts.
- Utilize diagrams to visualize the digestive system and enzyme functions.
- Practice with lab scenarios, as practical understanding can help with theoretical knowledge.
For precise questions, it's helpful to refer to past papers or revision guides specific to Edexcel IGCSE.