Lesson Plan Template: General Lesson Plan
Learning Objectives: What should students know and be able to do as a result of this lesson?
Students will describe the functions of monosaccharides and disaccharides.
Students will construct diagrams of monosaccharides and disaccharides.
Prior Knowledge: What prior knowledge should students have for this lesson?
SC.912.N.1.1 – Define a problem based on a specific body of knowledge
SC.912.L.18.12 – Discuss the special properties of water that contribute to Earth's suitability as an environment for life: cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a solvent.
SC.912.L.18.1 – Describe the basic molecular structures and primary functions of the four major categories of biological macromolecules
Guiding Questions: What are the guiding questions for this lesson?
- What molecules are formed in the dehydration synthesis reactions?
- What bonds are holding the two monosaccharides together?
- How would you break the bonds between the two monosaccharides? Do you think the reaction is reversible?
Teaching Phase: How will the teacher present the concept or skill to students?
The teacher will use the attached PowerPoint to present information about carbohydrates, including the function of the molecules in living things and the chemistry behind the bonding of the monomers. It should be mentioned that the bonding of these molecules is important to maintaining the structure of various components of plants and animals, and the type of bond between the monomers is essential in determining what our body needs to obtain energy from the compounds. The teacher may also want to show the Crash Course video "Biological Molecules - You Are What You Eat" but be aware that the video includes other biological molecules in addition to carbohydrates.
Guided Practice: What activities or exercises will the students complete with teacher guidance?
The teacher should use two molecules to show the students how to perform dehydration synthesis. Then the teacher should draw the structure of the new compound on the board. This is done to show both what the new structure looks like as well as how to draw the new bond that the students will create in the lab activity.
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the lesson?
The students will perform a paper lab to reinforce the concept of dehydration synthesis to form disaccharides from monosaccharides. Each student will be given a monosaccharide with a removable hydroxide group. The students will go around the room to perform dehydration synthesis to form three different disaccharide molecules. During the lab, they will draw the structure of the disaccharides formed as well as determine the number of carbon, hydrogen, and oxygen atoms in each molecule. This is to allow them to compare and contrast the structure of the monosaccharide and disaccharide molecules. They will then answer questions on the structure and function of the molecules.
Note: Printable molecules are attached. The squares on the printable models indicate where Velcro should be added to allow students to form "bonds." Two pieces of Velcro should be added to the back of oxygen to form the two bonds needed.
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
Have three pairs of students present their last disaccharide to the class. Choose pairs that will each present a different molecule so that sucrose, lactose, and maltose are all covered. Review how the bonds were formed through dehydration synthesis, which resulted in both the disaccharide and a water molecule.
The teacher should ask the students if the differences in the three structures would affect their functions. If this is done after the lab questions have been completed, then the process hydrolysis should be discussed and shown using the disaccharides created by the students. The three groups of students who presented their disaccharides could demonstrate hydrolysis to the class. This can be used to discuss the importance of water in the body and show why glycogen is used to store glucose in the body.
The questions at the end of the Carbohydrate Lab sheet should be used as a summative assessment for this lesson. The actual disaccharide activity in which they create the bonds should also be part of the grade. Teachers can use the attached rubric to evaluate this portion while circulating the classroom, observing students' work.
While the students are working, the teacher should walk around the room to determine if they are forming the bonds correctly when making the disaccharide molecules. This can be determined by seeing the bonds they have formed or by looking at the sketch of the molecules on their lab report before they answer the conclusion questions.
The students may also do a think/pair/share activity at the end of the class in which they develop an experiment about carbohydrates with food found in their homes.
Feedback to Students
The teacher should be walking around the room during the main activity of the lab, providing feedback to the students about the accuracy of the structures they are forming.