Type
of Lesson: The
Direct-Instruction Method.
Date:
...
Audience/Grade:
Grade 12 students and
those who are interested in this topic.
Subject:
Biology, Unit 4: Systems of Regulation, Chapter 13: Regulation of Glycemia.
Duration:
8 periods.
Analysis
of the learner: The
student has to know that the human body contains glucose, and that the liver
and pancreas have essential roles in regulating glucose.
Rationale:
Understanding that the regulation of
glycemia is a very important process in the human body, and any defect in this
regulation can lead to diseases either severe or mild. The students have also
to understand the function of the liver and pancreas in the regulation of
glycemia, and if one of them malfunctions or stops functioning completely will
result in hazardous consequences in the organism.
Objectives:
v The
students will be able to explain the variations in the blood glucose
concentration.
v The
students will be able to explain the role of liver in maintaining a constant
glycemic level .
v The
students will be able to explain the role of pancreas in the regulation of
glycemia.
v The
students will be able to predict how the system regulating glycemia functions.
v The
students will be able to differentiate between the role of the liver and the
role of the pancreas in regulating glycemia.
v The
students will be able to compare the hypoglycemic and hyperglycemic systems.
v The
students will be able to relate a certain disease (diabetes in this case) with
the function of both pancreas and the liver.
v The
students will be able to infer that the regulation of glycemia occurs also by feedback
control that includes the organs liver and pancreas.
Content:
Vocabulary:
-
Glucose: a simple sugar that is an important energy source in living
organisms and is a component of many carbohydrates.
-
Glycemia: The presence of glucose in the blood.
-
Glycogen: A substance deposited in bodily tissues as a
store of carbohydrates. It is a polysaccharide that forms glucose on
hydrolysis.
-
Liver: A large
lobed glandular organ in the abdomen of vertebrates, involved in many metabolic
processes.
-
Glycogenesis: The formation of
glycogen from glucose.
-
Glycogenolysis: The breakdown of glycogen.
-
Hepatectomy: Ablation of the liver.
-
Hepatocytes: Liver cells.
-
Amino acids: A simple organic compound
-
Glycerol: a colorless, odorless, viscous metabolic intermediate and structural component of lipids.
-
Fatty acids: a carboxylic acid
occurring as esters in fats and oils.
-
Neoglucogenesis: A metabolic pathway that results in the generation of
glucose from non-carbohydrate carbon substrates.
-
Adipose tissue: A type of connective
tissue.
-
Glucose-6-phosphatase: An enzyme that hydrolyzes glucose-6-phosphate
resulting in the creation of a phosphate group and free glucose.
-
Diabetes mellitus: The most common form of diabetes, caused
by a deficiency of the pancreatic hormone insulin, which results in a failure
to metabolize sugars and starch.
-
Juvenile diabetes: Type 1 diabetes, insulin-dependent diabetes, is a chronic condition in
which the pancreas produces little or no insulin.
-
Polyuria: production of abnormally large volumes of
dilute urine.
-
Glycosuria: Excess of sugar in the urine
-
Pancreatectomy: Ablation of the
pancreas.
-
Islets of langerhans: Groups of pancreatic
cells secreting insulin and glucagon.
-
Insulin: A hormone produced in the pancreas by the islets of
Langerhans that regulates the amount of glucose in the blood.
-
Glucagon: a hormone formed in the pancreas that promotes
the breakdown of glycogen to glucose in the liver.
-
Hypoglycemia: Deficiency of glucose in the bloodstream.
-
Hyperglycemia: An excess of glucose in the bloodstream
-
Receptors: An organ or cell able to respond to stimulus and transmit a
signal.
-
Target cell: A cell that bears receptors for a hormone, drug, or other
signaling molecule.
-
Beta cells: Insulin-producing
cells in the islets of Langerhans.
-
Feedback control: The regulation of the activity of an enzyme by
one of its products.
-
Hypothalamus: A region of the
forebrain below the thalamus that coordinates both the autonomic nervous system
and the activity of the pituitary, controlling body temperature, thirst, hunger,
and other homeostatic systems, and involved in sleep and emotional activity.
-
Lipolysis: The breakdown of fats
and other lipids by hydrolysis to release fatty acids.
Principles:
-
Measurement
of blood glucose concentration.
-
Identification
of glycemia regulation.
-
The role of liver in maintaining the
glycemic constancy.
-
The anatomical structures of the
pancreas play an important role in the regulation of glycemia.
-
The conditions that trigger insulin
secretion.
-
The area and mode of action of insulin.
-
The hormones of the hyperglycemic
system.
-
The conditions that trigger the
secretion of the hormones of the hyperglycemic system.
-
Glycemia regulation is ensured in the
body by feedback control.
Materials:
-
Book:
Life Science, Secondary Education, Third year, Life Sciences Section.
-
Whiteboard
-
Markers
-
Exercises
-
Questions
-
Test
-
Concept maps
-
Graphs
-
Schemas
Procedures:
Anticipatory set: Three case studies will be shown to the
students through slides; it will include three individuals with different
lifestyle which eventually leads them to diabetes. Thus the students will
deduce that these individuals are suffering from diabetes.
Body:
Input:
The students will be
provided with explanations, case studies and experiment analysis as examples.
They will answer to different questions and will be given exercises that will help
them understand the glycemia is regulated in the body and they will be able to
transfer these information to a new context.
Modeling:
After discussing the cases
in the anticipatory set, the teacher told the students that the chapter is
about regulation of glycemia, and she explained briefly the objectives:
-
The students will be able to explain the
variations in the blood glucose concentration.
-
The students will be able to explain the
role of liver in maintaining a constant glycemic level.
-
The students will be able to explain the
role of pancreas in the regulation of glycemia.
-
The students will be able to predict how
the system regulating glycemia functions.
-
The students will be able to differentiate
between the role of the liver and the role of the pancreas in regulating
glycemia.
-
The students will be able to compare the
hypoglycemic and hyperglycemic systems.
-
The students will be able to relate a
certain disease (diabetes in this case) with the function of both pancreas and
the liver.
-
The students will be able to infer that
the regulation of glycemia occurs also by feedback control that includes the
organs liver and pancreas.
After explaining the
objectives, she states that in each period one document will be covered with
the questions at the end of each document, and there will be exercises, and a
test.
The teacher starts
explaining the first document, and explains how glucose concentration can be
measured quickly, she shows them three methods: fehling test, glucometer, paper
strip test. Later on she explained how glycemia can vary, and she analyzed
graphs with the students.
After completing the
first document the students answered the questions found at the end of the
document with the guidance of their teacher.
In the second document,
she explained the role and function of the liver in the regulation of glycemia,
through experimental studies and schemas. After which together with the
students she solved the questions found at the end of the document. After
completing the second document the students answered the questions found at the
end of the document with the guidance of their teacher.
Next she explained the
role of the pancreas in regulating glycemia in the third document. She explained
that one of the clinical observations of a malfunction in the pancreas is
diabetes. They analyzed also experimental studies and deduced the role of the
pancreas as two functional sets. Then they answered the questions found at the
end of the document.
In the fourth document
she explained the hypoglycemic system, insulin secretion, the role of insulin,
and the mode of action of hormones, and they analyzed graphs. After completing
the explanation of the document the students answered the questions found at
the end of the document with the guidance of their teacher.
In document five she
explained the hyperglycemic system, and the role of major hyperglycemic factor
which is the glucagon. The students answered again the questions found at the
end of the document.
In the last document,
she explained the feedback controlled that plays an important role in the
regulation of glycemia, in which the central nervous is involved and there’s a
neuro hormonal integration. She guides the students to answer the questions
after completing her explanation.
Check for understanding:
To check their understanding
the teacher asked the students to:
-
List the three methods for rapid measurement
of glucose concentration.
-
Analyze graphs that include variations in
glycemia.
-
What are the consequences of hepatectomy?
-
What reactions occur in the liver? Explain
each.
-
What are the 2 types of diabetes? Explain
each stating the main sysmptoms.
-
Why is the pancreas said to have two
functional sets?
-
What is the role of the pancreas in
regulating glycemia?
-
What is the role of insulin in regulating
glycemia?
-
What is the role of glucagon in regulating
glycemia?
-
Describe the neuro-hormonal integration.
-
How does the autoregulation of glycemia occur?
Guided practice:
-
Answering the questions found at the end of
documents 1to 6.
Independent practice:
-
Exercises 1 to 6 were homework.
Closure: The teacher summarized the chapter, and
reviewed the important principles.
Assessment:
-
A test
Reflection:
-
More effective concept maps could be used.
-
Should
I include worksheets for next time?
-
Did the students understand the important
principles?
-
How can I improve my explanation?
-
Was it enough to assess only with a test?
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