How write a lab report

The big picture

    We will be using the inductive method.  In doing so we have collected a bunch of facts and we hope to make some generalizations.  In particular, we have examined the compositions of various plant and animal tissues and we hope to see some patterns that may divide the two kingdoms and see other patterns within the kingdoms.

In a lab report you want to give some background, tell the person exactly what you did, and then inform them of the significance of the work.

Technical points

    Double space: This allows the editor (me) to make marks on your paper and makes it easier for everyone to read.

    Indent new paragraphs

    Spell and grammar check: If you are not using software that allows this another person also works.  Even if you have
    that option you should let other people read it.  If it doesn't make sense to them it will not make sense to me.

    Speak English and be professional.  I hate colloquial speech (e.g. it was like hot and stuff).

    Do not use the word prove;  support or suggest is appropriate

    Underline or bold the section titles (Introduction, Methods, etc.)

    LET ME READ IT BEFORE YOU HAND IT IN (AT LEAST TWO DAYS BEFORE)

Format

    The title: should indicate the purpose and the group of organisms it involves.  In our case it was a qualitative analysis of various plant and animal substances.  The title should be centered with you name, date, and class underneath.

    The introduction. You are going to say things like monosaccharides, unsaturated in the results and discussion.  The point of the introduction is to inform the reader what these things are. The two fatty acids, proteins, and sugars should get their own paragraph.  You should also state the purpose or goal of what you are trying to figure out.  "Here we will determine the composition of various......".

    Methods. Another class should come in and be able to replicate the experiment using your methods section. Note: it is the results that should be replicated so it isn't important who did the experiment or the group size.

    Results: A table is appropriate.  List the substance and what it contains.  I provide a summarizing list of all the classes results under the table.  In your table put all the similar substance together (Bacon, lard, yolk; then the oils, etc.)
 
 
Substance Saturated Fat Unsaturated Fat Protein Polysaccharide Disaccharide Monosaccharide
Bacon + - + - - -
Yolk + - - - - -
Apple Juice - - - - - +
Corn Starch - - - + - -
 

    Discussion.  Here I ask you to summarize the results and to give them meaning.  What do I mean by "meaning "? It is the goal of theories to encompass a number of phenomenon with a lesser number of generalizations.  We looked at substances from both plants and animals.  Was there a difference?  What about the fruits (apple juice, grape juice, banana and avocado)?  The seeds (flour and corn); the nuts (olive oil and soybean oil)?  What about things with similar function (cotton vs hair; seeds vs. yolk).  Go out on a limb but only do so if you can back it up.

    The animal tissues that we looked at were just vertebrates (birds and mammals) we didn't look at insects, mollusks, jellyfish, and the other 98% of the animals on the planet.

    The paper was to show you what is the main composition of plants.  Use this as your main generalization. Remember: fruits and seeds are just a small part of what plants are

The data (I am pooling all the results from all the classes)

    Substance                        Contains

    Egg white                         Protein and fat
    Egg yolk                          Saturated Fat
    Banana                            Polysaccharides
    Avocado                          Fat
    Grape Juice                    Monosaccharides
    Apple Juice                    Monosaccharides
    Paper                             polysaccharides
    Cotton                            polysaccharides
    Flour                                polysaccharides
    Soybean Oil                    Unsaturated Lipid
    Corn Flour                    Polysaccharide
    Olive Oil                        Unsaturated Lipid
    Fingernail                        Protein
    Hair                                Protein
    Bacon                            Protein + Saturated Fat
    Lard                            Saturated Fat
    Potato                        Polysaccharide
    Table Sugar                 Disaccharides

In the methods section we used approximately 2 ml of all the substances plus 2 ml of the reagents (iodine, bromine water etc.)
Use the methods section in the Lab Protocol to get the information for this section.

For the introduction feel free to include diagrams (don't use mine).  If you get them from the internet then cite them by provi ding the URL (web site) underneath

I would go do some research in the library or internet for more information (nutritional book are probably useful).

Useful Links

Maricopa Community College

University of Minnesota

University of Florida  (I like this one)

If you do a web search try using specific term like monosaccharide, amino acid, avocado etc.
 
 
Sample lab report (this is not perfect but the style is acceptable)
 

Qualitative analysis of plant and animal material
Your name
September 24, 1998
Botany Lab
Thursday, 12:00

Introduction

Carbohydrates are compounds having an empirical formula of (CH2O)n that are commonly referred to as sugars and starches. These groups are further divided into those of monosaccharides, disaccharides, and polysaccharides.

These groups are further divided into those of monosaccharides, disaccharides, and polysaccharides.

Monosaccharides are simple sugars containing a single carbohydrate unit. Likewise, disaccharides are those sugars containing two carbohydrate units. Polysaccharides, as its name implies, are composed of multiple carbohydrate units.

Lipids are hydrophobic molecules such as fatty acids, triglycerides, and phospholipids. For our purposes, we concerned ourselves with only the fatty acids. They are divided into two categories, saturated and unsaturated fatty acids. Saturated fatty acids are those molecules containing a carbon chain that has the maximum number of hydrogens attached to it. On the other hand, unsaturated fatty acids composed of a carbon chain that contains less than the maximum number of hydrogens attached to it.

Proteins are made of long polypeptide chains of amino acids. Amino acids are composed of 3 main groups, a carboxyl group, an amine group, and an R group, which varies for each of the twenty amino acids.

We will determine the chemical composition of various substances. By doing so, we will be able to determine the makeup of plants and animals. More specifically, we will determine trends in the composition of various plants and animal structures such as fruits, hair, nails, and vegetables.



Methods and Materials

Fourteen types of tissues were used from various sources (see table 1). The first step of our experiment was to determine whether or not the sample was a fat. This step was carried out by simply spreading a small amount of the sample onto a brown paper napkin. If the sample left an oily remnant, it was indeed a fat. The names of the samples with no oily remnant were recorded, and the samples set aside. Next, those samples that were fats were treated in a test tube of 2 ml of a clear solution containing water and bromine. This step was to divide these fats into its two categories of fatty acids—saturated and unsaturated. To corroborate our findings, we treated the same fats in a test tube of 2 ml of a potassium permanganate solution.

Secondly, the non-fats previously set aside were submerged in a test tube of 2ml of an iodine solution to determine whether there were sugars in the form of polysaccharides present. Treating them in test tubes with 2ml of Benedict’s solution further tested those samples showing no change in the iodine solution coloration. As with the previous treatments, a color change indicated a positive chemical reaction. In this case, monosaccharides showed the positive reaction. Those that did not react were ruled disaccharides.

As a separate part of this experiment, five tissues were tested for the presence of protein. They were submersed in a test tube of nitric acid and monitored. Those showing a yellow color, a positive reaction, did indeed contain protein. If no color change was observed, no protein was present in that tissue.

 

Results
 
 
Substance
Saturated Fat
Unsaturated
Fat
Protein
Mono-
Saccharine
Di-
Saccharide
Poly-
Saccharide
             
Sugar
--
--
--
--
 
--
Flour
--
--
 
--
--
 
Corn Starch
--
--
--
--
--
 
Apple Juice
--
--
--
 
--
--
Grape Juice
--
--
--
 
--
--
Banana
--
--
--
--
   
Vegetable Oil
--
 
--
--
--
--
Olive Oil
--
 
--
--
--
--
Lard
 
--
--
--
--
--
Egg White
--
--
 
--
--
--
Egg Yolk
 
--
--
--
--
--
Cotton Ball
--
--
--
--
--
--
Human Hair
--
--
 
--
--
--
Finger Nails
--
--
 
--
--
--
Table 1. Properties of Organic Substances

Conclusion

It is evident from the table above that certain trends in the composition of various organic substances

appeared. Samples of animal tissue repeatedly showed the presence of protein and saturated fats. In egg yolk

and lard, both places of stored energy, saturated fats were found. In the hair and nails of humans there was no

question as to the presence of protein. Likewise, tissues extracted from plants repeatedly tested positive for

the presence of unsaturated fats and carbohydrates. Although the following samples differed in the type of

sugar found in their tissues, the presence of these sugars is evident of the presence of carbohydrates. Fruit

juices proved to be monosaccharides, while table sugar showed properties of disaccharides. Bananas

showed trends toward both polysaccharides and disaccharides. Cornstarch and flour also proved to be a

source of polysaccharides.
 

Final warning: Late and plagiarized lab reports are automatic zeros

I'm still working
 
 


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