Biological Molecules
Overview
The food you eat, the muscles you move and the enzymes that digest your lunch are all built from the same handful of chemical elements. Carbon, hydrogen, oxygen and nitrogen combine in different arrangements to produce carbohydrates, lipids and proteins, the three families of biological molecule that underpin virtually every process in a living cell.
In this lesson you will learn the structure of each molecule family, discover how enzymes catalyse reactions with lock-and-key specificity, investigate how temperature and pH affect enzyme activity, and master the food tests that identify glucose, starch, protein and lipid in the laboratory.
Objectives
- Identify the chemical elements present in carbohydrates, proteins and lipids (fats and oils)
- Describe the structure of carbohydrates, proteins and lipids as large molecules made up from smaller basic units
- Investigate food samples for the presence of glucose, starch, protein and fat
- Understand the role of enzymes as biological catalysts in metabolic reactions
- Understand how temperature changes can affect enzyme function, including changes to the shape of active site
- Investigate how enzyme activity can be affected by changes in temperature
- Understand how enzyme function can be affected by changes in pH altering the active site
- Investigate how enzyme activity can be affected by changes in pH
Mind map
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Flashcards
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Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Biological Molecules. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which elements are present in proteins but NOT in carbohydrates? A) Carbon and oxygen B) Hydrogen and oxygen C) Nitrogen (and sometimes sulfur) D) Phosphorus Answer: C
- What is the building block of proteins? A) Fatty acids B) Monosaccharides C) Amino acids D) Nucleotides Answer: C
- Which food test reagent is used to detect starch? A) Benedict's solution B) Biuret solution C) Iodine solution D) Ethanol Answer: C
- What happens to an enzyme at temperatures above its optimum? A) It works faster B) It divides C) Its active site changes shape permanently (denaturation) D) It dissolves Answer: C
- A triglyceride is made from: A) Three amino acids and one fatty acid B) One glycerol and three fatty acids C) Three glucose molecules D) One glucose and three amino acids Answer: B
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