sample essay - stem@lad

8/6/2019 Sample Essay - STEM@LAD

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Sample Essay STEM@LADThis document will help you format your essay according to the APA Guidelines.

GENERAL GUIDELINES:

Typed, double spaced on standard paper (8.5 x 11) Black ink 1 inch margins on all sides 12 pt. font Times New Roman or similar font

ESSAY SECTIONS:

1. Title Page2. Main Body3. Reference Page

IMPORTANT STEM@LAD INFORMATION:

You may hand in the essay draft as many times as you want to improve your grade. Ideallyyou should hand in the draft of the essay a week or two before the deadline.

You must hand in the essay draft at least 3-4 days before the final oral presentation.

Please review the following pages

where you will find a sample essay

with the APA Style guidelines youshould follow.


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1

Immunology in Focus:

Antibody Structure and the Generation of Diversity

Natalia L. Torres-Marn

200-00-0000

University of the Sacred Heart

BIO 320: IMMUNOLOGY

The title of your paper

should be centered and

double spaced.

NOT all capital letters

Name and last

name of the

author of the

essay.

If there is more

than one author,

include all the

names.

Page

numbers

should be at

the top right

corner.

APA recommends

that the title should

not be more than 12

words long.


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Our immune system relies on different types of cells and molecules in order to

protect us from the millions of pathogens and antigens it encounters every day. The

humoral response of antibodies plays one of the most important roles in the immune

system. The human body can produce over 10 million different antibodies in a lifetime.

Changes in the genes of B-lymphocytes allow each antibody to recognize unique antigenic

determinants.

The interaction between the antibody and the antigen depends on important binding

sites. The Fab portions of the antibody achieve antigenic recognition. Fabs, the antigen

binding fragments, are located at the top of two ends of a Y-shaped structure that

constitutes the antibody. The antibody recognizes a small portion of the antigen called the

epitope, or specific receptor. On the other hand, the Fab forms a surface complementary to

the specific receptor called the paratope (Male, Brostoff, Roth & Roitt, 2006, p. 68). The

paratope then bonds with the epitope in order to initiate a humoral response of cell

mediated immunity.

It is important to note that the Fab is a highly variable region of the antibody.

However, the crystallizable fragment known as Fc is not variable. The Fc also accounts for

the biological properties and functions of the antibody. Hence, if this fragment is altered,

the antibody will not function properly. For example, immunoglobulin A (IgA) is an

antibody responsible for the optimization of antigens in the mucose-assotiated lymphoid

tissue (MALT). This includes protection of the respiratory, gastrointestinal, and

reproductive tracts (Male et al., 2006, p. 74). Overall, the crystallizable fragment of IgA is

responsible for the efficient functioning of the MALT.

Indent

paragraph

five

spaces

(Tab)

Follow APA Style in-

text citation guidelines

This book should be

mentioned in the

Reference Page at

the end of the essay.

Introduc

Body

aragraph

#1

If a book or article has more

than one author, mention allthe authors the first time

you cite the source.

In subsequent citations, only

use the first author's last

name followed by "et al."


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An antibodys structure is responsible for an efficient and successful response to

pathogenic attacks. An antibodys Y-shaped structure is made up of four molecules joined

by disulfide bonds. Johnstones video (1988), shows that antibodies are composed of two

heavy chains and two light chains. The two long heavy chains are joined together by

disulfide bonds in the middle and in the end. The other end of the pair of heavy chains

arranges to make the top form a Y shape. These two segments of heavy chains are joined

with the shorter light chains by disulfide bonds.

The different types of immunoglobulin vary in their configurational arrangements

and functions. For example, there are four variants of the IgG antibody. IgG1, IgG2, and

IgG3 trigger the complement cascade effectively. However, Male et al. (2006) explained

that IgG4 antibodies are reported to be inactive. Interestingly, it is also the only antibody

that goes through the placenta to protect the baby (p. 73).

There are two variants of IgA antibody. IgA does not circulate in the blood. It is

secreted externally in tears, saliva, mucus, and breast milk. According to Johnstone (1988),

there is a receptor called polyIg which binds IgA to allow its passage into the blood stream

when necessary. On the other hand, IgD and IgE are monomers involved in the allergic

reactions as well as other functions yet to be discovered.

The wide variety of pathogens and antigens that we encounter every day have a

direct effect on the diversity of the antibodies our cells produce. The genetic code, as well

as the structure of its heavy chains, plays an important part in the vast array of about ten

million antibodies, which our bodies produce through time.

Use transition

words to make

your essay

clearer.

Follow APA Style in-

text citation guidelines.

This book should be

mentioned in the

Reference Page at

the end of the essay.

Always use the

past tense

when citing in

your essays.

E.g., Smith

(2005) found

or Rivera

(1998) has

found.

APA recommendations for paragraph length:

- Single-sentence paragraphs are abrupt and should be avoided.

- Paragraphs that are too long lose the readers attention.

- Look for a logical place to break a long paragraph or reorganize the material.


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Genetically, antibodies are incredibly diverse. Millions of different B-lymphocytes

can differentiate from a single stem cell in a bone marrow. Chromosome 14 codes for the

heavy chains, chromosome 2 for the kappa light chains and 22 for the lambda light chains.

The random transcription of each type of chain leads to the diversity of antibodies.

In all, having 400 possible light chains and eight thousand possible heavy chains,

there are 3.2 million variations for any given type of immunoglobulin (Johnstone, 1988).

However, it is important to account for somatic mutations of the V, J, and segments. As

stated by Male et al. (2006), one or more of the following factors can drive antigen

diversity: recombinational inaccuracies, somatic point mutation, nucleotide addition, and

gene conversion (p. 84). These account for even more variations of antibodies. This way, it

is possible for a single B-lymphocyte stem cell to be able to differentiate into about 10

million different antibody-forming cells.

Immunology in Focus is an informative introductory video of the human bodys

antibody response. In summary, Johnstones video regards the physical and varying genetic

structure of antibodies. The immune system partly relies on the humoral immunity as a

defensive barrier. It is important to know about the structure of antibodies in order to

understand how complex immunity is, and how diverse antibodies are. Consequently, we

are able to explain how the human body battles the hundreds of different types of pathogens

encountered every day.

Transition

Words

Transition

Words

onclusion


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References

Johnstone, A. (1988).Immunology in focus- Antibody structure and the generation of

diversity. Oxford, UK: IRL Press.

Male, D., Brostoff, J., Roth, D. and Roitt, I. (2006).Inmunology. Elsevier, Canada: Elsevier

Limited.

Alphabetize

authors by

their last

name.

Last name,

First Name

Initial

The word

Reference

should be

centered. NO bold,

NO underline, NOT

all capital letters

Second line

should be

indented one-

half inch from

the left

margin. (TAB)

The list should

be double

spaced, like

the rest of theessay.

Remember:

7In the Reference page you should only include the books, articles or web pages that youcited in your essay. If you read a book or an article and did NOT cite it in the essay, do NOT include

it in the Reference page.

sample essay - stem@lad

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