1. Lab 2 Nutrition and the Cell
BY 102
Zach Nolen
Lab 2 Nutrition and the Cell

2. Why is nutrition important?

3. Why is nutrition important?
It is important to know about nutrition, so that we can understand how the food that we eat helps to keep our bodies functioning.
The Science of Nutrition is the relationship between food (nutrients) and the health of the body.
Fortunately, in America, we do not have to worry about planning our meals to ensure that we get all of our required nutrients.
However, generally our eating habits are not the best when choosing what is best for us to eat.

4. Types of Nutrients Six types of nutrients: Protein Carbohydrates
Lipids
Vitamins
Minerals
Water
Picture References:

5. Proteins
Proteins are composed of amino acids, which are linked together by peptide bonds and are called polypeptides.
Proteins play a role in proper muscle development, regulation of body fluids, development of hormones, and the production of enzymes.
Antibodies are a type of protein

6. Proteins
There are 20 different amino acids found in animal and plant proteins.
Of these, 9 are “essential” which means that they can not be made by the body and must be obtained through diet.
About 20% of our total body weight is proteins
50% of the body’s protein is muscle, while the other 50% is divided between bone, skin, enzymes, blood cartilage, etc.

7. Differences between plant and animal protein.
Animal protein is referred to as “complete” protein because all essential amino acids can be found in a single source.
Plant sources are referred to as “incomplete” because they do not contain all essential amino acids.
A complete source of protein can be obtained from plants by eating a combination of grains and beans.

8. Carbohydrates
Carbohydrates function as a major source of energy for the body.
A single macromolecule is called a monosaccharide (glucose), two sugar molecules are called a disaccharide (sucrose).
Long chains of sugar molecules are called a polysaccharide (starch).
It is recommended that 55-60% of daily caloric intake be made up of carbohydrates.
If there is not enough energy from carbohydrates, the body will begin to break down proteins to create energy.

9. Carbohydrates Plants are the main source of carbohydrates.
What is the only non-plant source of carbohydrates?
Lactose in milk
Carbohydrates are broken up into three groups: simple sugar, starch, and dietary fiber.
Nearly 70% of daily carbohydrate intake is supplied by simple sugars, which has increased from 33% at the beginning of the 20th century.

10. Lipids Lipids are commonly known as fat, which our bodies need.
In healthy men and women, what percent of body weight is fat?
Men: 15-18%; Women: 18-23%
There are several terms used to describe dietary fat:
Saturated – solid at room temp (animal fat)
Unsaturated – liquid at room temp (vegetable oils)
Trans-fatty acid – hydrogen enriched vegetable fats (margarine and shortenings); very unhealthy

11. Lipids
Excess fat consumption leads to weight gain, which can lead to fat in the blood which causes heart problems.
Recommended fat consumption should be 30% of our caloric intake.
Excess fat consumption can lead to high cholesterol which can cause heart problems.

12. Vitamins and Minerals
Vitamins are organic substances required in very small amounts that perform specific metabolic functions in the body.
There are 13 vitamins that are required for good health.
Generally, if you have a balanced diet, then you should receive adequate amounts of vitamins.
If you do not have a balanced diet, you may wish to take vitamin supplements to improve general health.
Minerals are basic elements (iron), not some complex molecules.
We will not be testing for vitamins and minerals in this lab.

13. Testing for different nutrients
To test for proteins, we will be using Biuret’s reagent.
To test for carbohydrates, we will be using Benedict’s solution to test for simple sugars and Lugol’s solution to test for starch.
To test for lipids, we will be using Sudan IV (which I will add).

14. - + + - + - + - Results Biuret’s Test Lugol’s Test Sudan IV Test
Benedict’s Test
Picture References: + - + -

15. Review Questions What are the 6 types of nutrients?
What solution do we use to test for:
Protein?
Starch?
How many vitamins are essential for good health?
In healthy individuals, which gender has a higher percentage of fat?

16. Before you leave lab! Clean up! Take tape off of test tubes
Make sure you clean used test tubes and place in the bin next to the sink
Wipe down your work station
Let me check your station before you leave

17. Before next lab! Review topics covered in lab today
Read the next lab (Lab 4)
Do the online prelab
Complete questions 1-15 on page (omit #12)