Nutrition Physiology Lesson Plan

NUTRITION PHYSIOLOGY LESSON PLAN

GRADE LEVEL(S): 9-12

TITLE: Protein Synthesis and Digestion

NEXT GENERATION STANDARDS:

Employ the healthiest choice when considering all factors in making a decision. (HE.912.B.3.6)

Implement strategies and monitor progress in achieving a personal health goal. (HE.912.B.4.3)

Analyze the role of individual responsibility in enhancing health. (HE.912.P.1.1)

NATIONAL HEALTH STANDARDS:

Students will comprehend concepts related to health promotion and disease prevention to enhance health.

Students will demonstrate the ability to practice health-enhancing behaviors and avoid or reduce health risks.

BACKGROUND: This lesson focuses on mastering key concepts of replication, transcription, and translation in a creative way. The students will first learn about the processes, and will then complete an activity based on knowledge gained.
The teacher also needs to check the availability of a computer lab for activity extension.

OBJECTIVES:

The student(s) will be able to:

1. Analyze the structure of DNA.
2. Determine how the structure of DNA enables it to reproduce itself accurately.
3. Sequence the steps involved in protein synthesis.
4. Categorize the different kinds of mutations that can occur in DNA.

MATERIALS:

Legal-sized paper for comic strips, copies of student notes for student distribution, and crayons or colored pencils. Students will also need to know how to make a storyboard with Microsoft Word. (If a computer lab is not accessible, you can make this part of the assignment optional.)

LCD Projector
Laptop

STUDENT-LEARNING SKILLS:

The student will illustrate the creation and copying of the molecular structure of DNA and RNA. They will accomplish this by creating a comic strip and/or storyboard that graphically describes transcription and translation.

PROCEDURE:

PART 1

1.) Ask students to look around the room and list 3 physical characteristics that make them stand out from anyone else in the room. (Ask for volunteers to read their answers).
Now get them to think of some physical characteristics that they share with their parents. (Answers will vary)
Then ask students: What essentially makes us all different? (Answer= DNA)
Tell them that today they will be exploring their own DNA code, how they can get more of it (replication), and how our body reads it (transcription & translation).

2.) Distribute the student DNA outline and begin instruction on DNA replication, transcription, and translation (protein synthesis). Upon completion of notes, students should be able to pinpoint all key concepts of protein synthesis. Use this Thinkfinity animation of protein synthesis as a review.
After an informal teacher assessment has been made, the students may proceed on to the enrichment activity.

This website gives a brief overview of the process of protein synthesis.

3.) Allow the students to form co-ed groups for this activity and decide which member is going to be the author and which member is going to be the illustrator.
Give each group a copy of the key points of protein synthesis. The worksheet titled "Protein Synthesis Comic Strip" gives detailed directions for making the comic strip.

4.) Use legal-sized paper to make a comic strip.

5.) Have students make sections on the paper for each scene.

6.) Make sure each scene has a script and that the entire project is colorful. Display the completed comic strips on the classroom wall in a gallery format. Allow students 5 to 10 minutes at the beginning or end of class to view other classmate projects.

PART 2

1.)Ask students to read the attached information relevant to biological functions, biological values, energy values, and digestion/absorption of proteins.

2.)Encourage student discussions regarding digestion and absorption of proteins. Ask questions such as Why do we care about proteins?, Why should we eat proteins?, What happens after we eat proteins?

Attachments: / Protein Synthesis Comic Strip.doc
DNA Outline.doc
StoryboardRubric.doc
DNA Powerpoint.ppt
The website for the attachments is:

STUDENT ASSESSMENT:

A rubric is used to grade the digital storyboard and comic strip.

HOME EXTENSION: The students may go to the computer lab and make storyboards using their comic strip as a guide. Students needing a challenge may research what happens when transcription and translation goes wrong. They can add pictures of these effects to the end of their storyboard.

VOCABULARY:protein transcription, protein replication, protein translation, amino acid, DNA, RNA, enzyme, hormone

Functions

Biological Functions of

- Structural Proteins,

- Physiologically Active Proteins, and

- Nutrient Proteins.

There are three main functions for protein – structural function, physiologic function and nutrient function.

Structural Proteins

Structural proteins possess mechanical strength, because of the way their amino acids and polypeptide chains are arranged. This enables them to be involved in the formation of muscle tissue. Some structural proteins are quite rigid (collagen in connective tissue) whereas others are elastic (elastin in arteries).

All amino acids supplied by protein participate in growth and tissue maintenance. But some also perform other important physiologic and metabolic roles.

Physiologically Active Proteins

Physiologically active proteins are involved in the production of enzymes and hormones, nucleo-proteins and plasma proteins.

Enzymes are the largest single group of proteins and are often referred to as organic catalysts. In fact without enzymes no biological process could take place and life would be impossible. Enzymes have many uses in food manufacture e.g. papain and bromelin used to tenderise meat.

Some hormones are also proteins and carry out many important metabolic processes. Nucleoproteins are involved in the heredity process. They can be found in meat.

Plasma proteins are responsible for carrying essential substances around the body e.g. haemoglobin carries oxygen in the blood. They maintain physiological pH and osmotic balance and are necessary for the clotting mechanism and the immune response.

Nutrient Proteins

Nutrient proteins are those proteins that provide the essential amino acids (these must be taken in the diet as they cannot be made in the body). These are proteins that have a nutritional function e.g. caseins in milk that are passed from the mother to her offspring. The casein provides the essential amino acids for the child. Animal proteins are the main source of nutrient proteins.

Biological Value

The biological value of a protein is a measure of the quality of a protein. The biological value of a protein food is measured by the number of essential amino acids it contains in proportion to body needs. It is written as a percentage. Eggs have 100% biological value. This means that the body can use all the protein in eggs.

Complete Protein

Proteins which contain all the essential amino acids in the correct proportion have a high biological value (HBV) and are known as complete proteins. Most of these are from animal sources.

Incomplete Protein

Proteins which are deficient in one or more of the essential amino acids are known as low biological value (LBV) or incomplete proteins. These are usually from vegetable sources.

Complementation

Many proteins have the ability to make good the deficiency of another. For example, at one meal, a person might eat a food which is low in one amino acid along with another food which is a good source of this amino acid. The two foods combine to give all the essential amino acids. This is known as the supplementary value of a protein. For this reason, vegans can stay healthy on a totally vegetarian diet. Take the example of beans on toast. Wheat/bread is low in the essential amino acid, lysine, but high in methionine; pulses are high in lysine with reduced methionine. Other complementary proteins are maize and beans, and peanut butter sandwiches.

Energy Value

Contribution to Total Energy Value of Average Diet

One gram of protein is needed daily for each kilogram of body weight. More is required by children, adolescents, pregnant and nursing mothers.

A well balanced diet is one that contains one sixth protein, half from animal sources and half from vegetable sources. In western countries most people eat more protein than they need. At least one-third of protein intake should be of high biological value.

One gram of protein supplies 4 kcal/17kJ of energy.

Child 30-50g

Average adult 55-70g

Pregnant female 90g

Role of Protein as a Supplementary Energy Source

Protein is a source of energy. Most of the protein we eat is broken down into amino acids and used by the body for structural and repair work. If more protein than necessary is consumed the excess is broken down by the liver and stored as energy.

Deamination

If more protein than necessary is consumed, the excess is broken down by the liver.

1. The amino group, NH2, is removed from the molecule and converted into ammonia and then urea. This is excreted in the urine by the kidneys.
2. The carboxyl group, COOH, is oxidised to provide heat and energy or is stored in the body as an energy reserve.

Digestion and Absorption

Hydrolysis of Protein and Digestion Sequences

When protein foods are eaten, the proteins are hydrolysed during digestion to produce amino acids. Hydrolysis takes place as a result of the action of water and enzymes on the various protein foods.

Digestive Gland / Secretion / Enzymes / Substances acted on / End product
Stomach / Gastric Juice / Pepsin / Protein / Peptones
Stomach / Gastric Juice / Rennin / Caseinogen in Milk / Casein
Duodenum / Pancreatic Juice / Trypsin / Peptones / Peptides
Ileum / Intestinal Juice / Peptidase / Peptides / Amino Acids

Absorption andOutline of Utilisation of Amino Acids

Amino acids diffuse into the blood capillaries in the villi of the small intestine and are carried to the liver via the portal vein.

Both essential and non-essential amino acids pass into the bloodstream and body tissues where they are synthesised to form new cells, hormones and enzymes and to repair tissues.

Source Of Energy

Excess amino acids are broken down to urea, which is excreted by the kidneys. Glucose is also produced as part of this process and is use for energy production. If the body does not require energy the non-nitrogenous residues are converted to fat and stored as adipose tissue.