Conclusion

Hello to everyone, this semester I was posting about several themes of my field of study, that is Biology. As the past semester I like this idea of writing about certain themes because I could expand my knowledge of the topic posted, expand my ability to write, read and speak English. I feel myself more security because this semester I had the opportunity to be part of the English Conversational course as a listener and this course gave me the skill to write and speak with more fluidly and helped me in my English course. I really hope that you enjoying and learning about the themes that I posted. Finally, I am so thankful with the professor because she always believed in me, and my ability to learn. Thank you for getting the best of me.

Happy summer vacation!!!!

Human Circulatory System

In this last week I will write about a body system that is very important to us. This system is very necessary for the human being because it is responsible for transporting oxygen and nutrients to cells. Further, removes their (cells) metabolic wastes that must later be removed by the kidneys, urine, and exhaled air in the lungs, rich in carbon dioxide. This system is called Circulatory System. The Circulatory System consists of the heart and blood vessels, including veins, arteries and capillaries.

Blood is the fluid that circulates throughout the body through the Circulatory System. It is a fluid tissue, consisting of water and organic and inorganic substances (minerals) dissolved, forming blood plasma and three types of blood cells or cellular components: red cells, white cells and platelets. A drop of blood contains about 5 million red blood cells, white blood cells 5,000-10,000 and about 250,000 platelets. All these cells have a specific function in our body for example, the red blood cells are responsible for the distribution of molecular oxygen, the white blood cells (leukocytes) have an important role in the immune system to perform cleanup work (phagocytes) and defense (lymphocytes), also you can click on immune system to see more information about this system, and the platelets are fragments of very small cells, used to plug wounds and prevent bleeding. Nevertheless, the heart is the main organ of the Cardiac System and one of the most important human being.

The heart is a muscular organ responsible for receiving and pumping blood so that it circulates throughout the body, about a 60 to 100 time per minute. This organ consists mainly in a muscle called myocardium or heart muscle, and inside of the heart are found four chamber: two atria and two ventricles. Moreover, the veins are those that carry blood to the heart from the body organs. Those who get to the heart are two vena cava veins and four pulmonary veins. They reach the venae cavae to the right atrium and pulmonary, left atrium. Veins carry blood to the heart and continually open freely on their walls. Nevertheless, the arteries are the vessels that carry blood from the heart to the organs. From the heart the pulmonary artery and the aorta large, one or the right ventricle and the other, the left ventricule. Unlike veins, these arteries do not work freely, since the administration of blood to them is governed by the sigmoid valves, leaving ot only when blood pressure is exerted when the ventricles contract.

Finally, the circulatory process is a closed loop that starts and ends in the heart. The right cavities are what drive the blood containing wastes the body to the lungs for disposal. In the lungs oxygen taken up by the respiratory and oxygenated blood enters the heart through the left atrium, being driven intro the body form the left ventricle it is collected. Thus the blood with waste reaches the right atrium through the vena cava, while oxygenated blood reaches the heart through the pulmonary veins and is distributed throughout the body from the aorta. Entire circulatory process is divided into two parts which are called: greater or general circulation, the circulation of oxygenated blood throughout the body and the return of venous blood throughout the body to the heart, and smaller circulation or pulmonary, the venous circulation which sends blood to the lungs and oxygen collecting these, into the heart oxygenated blood.

These two videos have an explanation for you about how our Circulatory systems works in the body,
https://www.youtube.com/watch?v=_qmNCJxpsr0 and https://www.youtube.com/watch?v=_lgd03h3te8

This image is in Spanish but I like because show to you each part of the circulatory system.

1. Arteries of the head
2. Pulmonary artery system
3. Venous system of the larger circle
4. Arteries and veins of the lower limb
5. The heart
6. Aorta and large arteries
7. Capillary circulation
8. Arteries and veins of the upper limb

Lactic Acid

In this week I will write about an acid that is released when our muscles are without the presence of oxygen. This acid is called Lactic acid, is an organic compound with the formula CH3CH(OH)CO2H. It is a white, water-soluble solid or clear liquid that is produced broth naturally and synthetically. With a hydroxyl group, lactic acid is classified as an alpha hydroxy acid (AHA). In the form of its conjugate base called lactate, it plays a role in several biochemical processes. The lactid acid system is able of releasing energy to resynthesize ATP without the involvement of oxygen and is called anaerobic glycolysis. 

Glycolysis (breakdown of carbohydrates) produces the formation of pyruvic acid and hydrogen ions. The pyruvic acid molecules undergo oxidation in the mitochondrion and the Krebs cycle begins. A build up of H+ will make the muscle cells acidic and interfere with their operation so carrier molecules, called nicotinamide adenine dinucleotide (NAD+), remove the H+. The NAD+ is reduced to NADH that deposit the H+ at the electron transport gate (ETC) in the mitochondria to be combined with oxygen to form water. Furthermore, if there is insufficient oxygen then NADH cannot release the H+ and they build up in the cell.

To avoid the rise in acidity pyruvic acid accepts H+ to produces lactic acid that then is dissociates into lactate and H+. Some of the lactate is diffuses in the blood stream and takes some hydrogen ions with it as a way of reducing the H+ concentration in the muscle cell. Our muscle cells normally have a  pH of  7.1 but if the build up of H+ continues and pH is reduced to around 6.5 then muscle contraction may be impaired and the low pH will pain (the burn). This point is often measured as the lactic threshold or anaerobic threshold (AT) or onset of blood lactate accumalation (OBLA). 

How the lactic acid works in our body: https://www.youtube.com/watch?v=ZaRsOjfEHyM

1. http://www.scientificamerican.com/article/why-does-lactic-acid-buil/
2. http://www.brianmac.co.uk/lactic.htm

Immune System

Multicellular animals have cells or tissues only they are facing the threat of infections. Some of these responses are immediate, so that an infectious agent can be contained quickly; others are slower, but also more specific for the infectious agent. Collectively, this protection is known as immune system. The human immune system is essential to our survival in a world full of potentially dangerous microbes, and a serious deterioration, can even a branch of this system, making us susceptible to serious infections that endanger life. Something that helps us to create resistance to pathogens in our system is immunity, this is the active ability to resist disease. The inmunity has two ways of working in our body, innate immunity and adaptive immunity.

Innate immunity, the body's built-in ability to recognize and destroy pathogens or their products, is lagerly a function of phagocytes, cells that can ingest, kill and digest most microbial pathogens. Innate immune responses develop within hour after contact and infections with a pathogen. Structural features such a the cell wall constituents shared by many pathogens interact with universal receptors on the phagocytes. The interactive phagocytes then active genes that lead to pathogen destruction.

Some pathogens are, however, so virulent that innate responeses are not completely effective. When this happens, the innate response phagocytes activate adaptive immunity to deal with these infections. Adaptive immunity is the acquired ability to recognize and destroy a specific pathogen or its products. Adaptive responses are directed at unique pathogen molecules called antigens. Phagocytes present antigen molecules to lymphoctes, key cells in the adaptive response. The antigens bind specific receptors on the lymphocyte, triggering genes that promote lymphocyte multiplication and production of pathogen-specific proteins that interact with the pathogen, marking it for destruction. A protective adaptive response usually takes several days tos develop; the strength of the adaptive response increases as the numbers of antigen-reactive lymphocytes increase.

So comparing the innate immune response between adaptive immune response, is that the recognition mechanism of innate immunity is that has rapid response (hours), is invariant, limited number of specificities and constant during response. However, the recognition mechanism of adaptive immunity is that has slow response (days to weeks), is variable, numerous highly selective specificities, improve during response, and is able to recognize old pathogens because the cells of this system have memory to destroy the old pathogens. Both immune systems have a common effector mechanism for destruction of pathogens. This video explain to you how our immune system works in presence of a pathogenic bacteria https://www.youtube.com/watch?v=zQGOcOUBi6s

This information will be found in the textbook,  Brock Biology of Microorganisms, 14th Edition- Madigan 

Skin

Today I will write about an organ that is very important to the human body, the skin. Without this organ the human body will have an ugly appearance. Really if we do not have skin what we would see would be our muscles. The skin is the largest organ of the body, made with several components, including protein, lipids, water and different minerals and chemicals. The skin protects us from microbes and the elements, helps regulate body temperature, and permits the sensations of touch, heat, cold and it is made to be tough and stretchy. Skin has three layers: the epidermis, the dermis, and deeper subcutaneous tissue (hypodermis).

The skin color is created by cells called melanocytes, which produce the pigment melanin. Melanocytes are located in the epidermis. The first layer is the epidermis, the outermost or top layer of skin, the part of the skin we can see, provides a waterproof barrier and creates our skin tone. It is too super thin on some parts of our body (eyelids) and thicker on others parts (the bottoms of our feet). Is the layer in charge of making new skin cells. This happens at the bottom of the epidermis and the cells travel up to the top layer and flake off, about a month after they form. In addition, giving skin its color, the epidermis makes melanin, which is whats gives our skin its color. Furthermore, protecting our body, the epidermis has special cells that are part of our immune system and help our stay healthy.

The second layer is the dermis,beneath the epidermis, it is much thicker and does a lot for our body, contains tough connective tissue, hair follicles, and sweat glands. This layer is in charge of making sweat, there are little pockets called sweat glands. They work making sweat, which goes through a small tubes and comes out of pores (sweating keeps us cool and helps us get rid of bad stuff our body does not need). Too, is in charge of helping our feel things, nerve endings in this layer help us feel things. The nerve send signals to our brain, making us know how somethings feels if it hurts, is itchy or feels nice when us touch it. The dermis is where we will find the roof of each tiny hair on our skin. Each root attaches to a tiny muscle that tightens and gives us goose bumps when we are cold or scared. This layer too make oil, and the oil keeps our skin soft, smooth and waterproof. Sometimes the glands make too much oil and give us pimples. By last, blood feeds our skin and takes away bad stuff through little tubes called blood vessels.

The last layer is the deeper subcutaneous tissue (hypodermis) or subcutaneous fat that is made of fat and connective tissue. The layer that have an important role in the body, has a special connecting tissue that attaches the dermis to our muscles and bones, and the blood vessels and nerve cells that start in the dermis get bigger and go to the rest of our body from here. Is the layer that helps keep our body from getting too warm or too cold. The fat pads our muscles and bones and protects them from bumps and falls.

This information can be found on this web page https://www.aad.org/public/kids/skin/the-layers-of-your-skin

Cloning

This week I'll write about a topic that is very important for science and that overdosed boom in recent years. The process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insect or plants reproduce asexually, is called cloning. There are different types of cloning: molecular, cellular, organismal naturally, artificial, reproductive, therapeutic, replacement generation and extinct species. Today I will focus on the molecular, cellular, organismal naturally and reproductive cloning. Now I will explain each of these types of cloning.

Molecular cloning is the process of making multiple molecules, commonly is used to amplify DNA fragments containing whole genes and also can be used to amplify any DNA sequence such as non-coding sequences, promoters and randomly fragmented DNA. Cellular cloning is when is derived a population of cells from a single cell. Then in nature some plants and single-celled organisms, such as bacteria, produce genetically identical offspring through a process called asexual repoduction. Furthermore, natural clones occur in humans and other mammals. The identical twins are produced when a fertilized eggs splits, creating two or more embryos that carry almost identical DNA. 

Finally, reproductive cloning is also known as somatic cell nuclear transfer. It is a technology used to generate an organism that has the same nuclear DNA as another organism. The genetic material of the core is transferred from a differentiated and donor adult cell to an egg or enucleated egg. When electroporation (electric shock) or chemical treatment (ionomycin) is used, the pores open and the DNA enters to enucleated egg.Too, the cell is stimulated to divide. Once the appropiate time acquires embryo is transferred into the uterus of a female until birth. 

An example of this type of cloning is Dolly the sheep. This sheep was the first mammal cloned in this way. Dolly was cloned on February 27, 1997 by Ian Wilmut. She died on February 14, 2003 because developed lung cancer, arthritis and weak inmune system. In the case of Dolly the genetic marker was the color of th head of sheep that donated the egg. In addition, other cloned animals like Dolly were goats, cows, mice, cats, rabbits and gaur. In 2001 the first animal cloned endangered (gaur). This animal died forty-eight hours after infection. And in Italy was cloned a type of wild sheep (mouflon) who still lives.

Most of this information was obtained from https://en.wikipedia.org/wiki/Cloning and https://www.genome.gov/25020028
The example of Dolly and the information below of the example was obtained from my genetic class that I took on spring semester of 2015 (January-May).

Antibiotics

Antibiotics are powerful medicines that fight bacterial infections. Correct use can save lives. Antibiotics kill bacteria or prevent them from reproducing. After taking antibiotics, the body's natural defenses are sufficient. It is importante to know that antibiotics do not fight infections caused by viruses such as cold, flu, most coughs and bronchitis, and sore throats, unless caused by strep. 

When you use antibiotics unnecessarily would only increase the risk of antibiotic resistance, so they are not routinely use. Antibiotics can be provided in several ways. Oral antibiotics, topical antibiotics and injections of antibiotics. The oral antibiotics are tablets, pills and capsules or a liquid, they can be used to treat most types of mild to moderate infections in the body. Topical antibiotics are creams, lotions, sprays or drops, they are often used to treat skin infections. By last, injections of antibiotics, they can be given as an injection or infusion directly into the blood or muscle, and are usually reserved for more serious infections. Furthemore, the mechanism of action of antibiotics are hat affectinhibiting the synthesis of the cell wall, inhibiting protein synthesis, DNA gyrase synthesis, among other effects. All this depends on the type of bacteria that the antibiotic is  affecting.

This video show to you how the antibiotics work in our body: https://www.youtube.com/watch?v=IVBCrzjOl40

Most of this information is from: https://www.nlm.nih.gov/medlineplus/antibiotics.html and http://www.nhs.uk/Conditions/Antibiotics-penicillins/Pages/Introduction.aspx

Trisomy 21

Last week I wrote about the function of the DNA in our cells. Today I will write about a genetic condition that is known around the world. This condition is Trisomy 21 usually known Down syndrome. This is because there is a genetic disorder caused by an abnormal amount of autosomal chromosomes: 2N + 1. The syndrome has three autosomal chromosomes 21 instead of two, 2N +1= 46 +1= 47. Down syndrome include low muscle tone, small mouth, people who suffer this syndrome, keep it open, because they do not have enough space for the tongue, peculiar eyelids, heart defects, mental retardation, and poor resistance to infection. In addition, 1 of 700 children born with the syndrome.

Although we know how Down syndrome occurs. Down syndrome occurs at conception, across all social groups and to parents of all ages. The trend of Down Syndrome increases with maternal age. After 35 years there is a dramatic increase in the possibility of having children with this syndrome. It is nobody's fault. There is no cure and it does not go away. Finally, this video https://www.youtube.com/watch?v=m2r4Y3rvnwo show to you a young man who has Down syndrome but this is not an impediment for him to succeed in life.

Some sentences that were presented here were obtained from http://www.downsyndrome.org.au/what_is_down_syndrome.html

Deoxyribonucleic acid (DNA)

Each chromosome has one long DNA molecule with hundreds or thousands of genes. Genes encode information for building proteins. DNA is inherited by offspring from their parents and controls the development and maintenance of organisms. Deoxyribonucleic acid (DNA) is the hereditary material in humans and almost all other organisms. Nearly every cell in a person's body has the same DNA. Most DNA is located in the cell nucleus, but small amount of DNA can also be found in the mitochondria.

Each DNA molecule is made up two long chains arranged in a double helix. Furthemore, each link of a chain is one of four kinds of chemical building blocks called nucleotides. These chemical building blocksor chemical bases are adenine (A), guanine (G), cytosine (G), and thymine (T). The chemical bases pair up with each other, adenine with thymine and cytosine with guanine to form bases pairs. The human DNA consists of about three billion bases. The bases are also attached to a sugar molecule and a phosphate molecule. The sugar and phosphate when are together they forms a nucleotide. By last, DNA can be replicate,  each strand of DNA in the double helix can serve as pattern for duplicating the sequence of bases, and when cells divide each new cell needs to have an exact copy of the DNA from the old cell.

Most of this information is from https://ghr.nlm.nih.gov/handbook/basics/dna 

Cell Reproduction

This week I will be writing about the process that the cell performs to reproduce, this process is called cell division. First of all, I want that you know what are a cells. The cells are the basic building blocks of alla living things. The human body is composed of trillions of cells. They provide structure the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions. Cells also contain the body's hereditary material and can make copies of themselves. Cells have many parts, each with a different function. Some of these parts, called organelles, are specialized structures that perform certain tasks within the cell. Human cells contain the following major parts cytoplasm, cytoskeleton, endoplasmic reticulum, Golgi apparatus, lysosomes and peroxisomes, mitochondria, nucleus, plasma membrane and ribosomes. 

You may be wondering what is the cell division. Cell division involves the distribution of identical genetic material, DNA, to two daughters cells. What is most remarkable is the fidelity with the DNA is passed along, without dilution or error, from one generation to the next. The cells have the process of mitosis and meiosis to perform cell division. Mitosis is a form of eukaryotic cell division that produces two identical daughter cells with same genetic component as the parent cell. Chromosomes replicated during the S phase are divided in such a way as to ensure that each daughter cell receives a copy of every chromosome. In actively dividing animal cells, the whole process takes about one hour. Mitosis involves six phases that are Prophase, Prometaphase, Metaphase, Anaphase, Telophase, and Cytokinesis.

Nevertheless, Meosis is the form of eukaryotic cell division that produces haploid sex cells or gametes (which contain a single copy of each chromosome) from diploid cells (which contain two copies of each chromosome). The process takes the form of one DNA replication followed by two succesive nuclear and cellular divisions (Meiosis I and Meiosis II). As in mitosis, meiosis is preceded by a process of DNA replication that converts each chromosome into two sister chromatids. As you read, Meiosis have two succesive nuclear and cellular divisions. Meiosis I and Meoisis II consist of six phases, as Mitosis. On Meiosis I are Prophase I , Prometaphase I, Metaphase I, Anaphase I, Telophase I, and Cytokinesis. Too, on Meiosis II are Prophase II , Prometaphase II, Metaphase II, Anaphase II, Telophase II, and Cytokinesis.

In this link, http://www2.le.ac.uk/departments/genetics/vgec/schoolscolleges/topics/cellcycle-mitosis-meiosis, you can encounter the definition of all phases are in each process. Finally, I want that you see three videos that I posted below. This videos explain to you in a graphic form the process of the cells and it can improve your knowledge.

This two videos show to you the process of Mitosis:

1. https://www.youtube.com/watch?v=DwAFZb8juMQ&list=PL7BpecGDIhhoBM8wazP45ky__HQrOE5IC&index=2
2. https://www.youtube.com/watch?v=C6hn3sA0ip0

This video show to you the process of Meiosis:

1.  https://www.youtube.com/watch?v=nMEyeKQClqI

     
 Bibliography:                    

• Cell definition: https://ghr.nlm.nih.gov/handbook/basics/cell
• Cell division definition: http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect16.htm
• Mitosis and Meiosis definition: http://www2.le.ac.uk/departments/genetics/vgec/schoolscolleges/topics/cellcycle-mitosis-meiosis

Biology and its branches

Hi, today I will go to write about what is biology and what are the branches in which it develop and the meaning of each branch. Biology is the science that studies living organisms. In the field of biology we study various organisms which are classified within the branch of it. These branches are as follow Cellular Biology or Cytology, Molecular Biology, Developmental Biology, Marine Biology, Physiology, Genetics, Zoology, Botany, Ecology and Microbiology. Now, like I wrote before, I will go to write the meaning of each branch. Too, I will divide the meanings of each biology in two sections.

The Cellular Biology or Cytology is the branch that studies the structure and function of cells. It is responsible for understanding the properties, structures, functions and the interaction with the environment of cells. The another branch is Molecular Biology. Molecular Biology is the area of Biology that studies the biological processes on a molecular level. It focuses on studying the interactions of different cell systems. The next, is Developmental biology, this studies the development of living organisms from birth until death. This biology is focuses on the genetic control of cell growth and cell differentiation and morphogenesis. The fourth biology is Marine Biology. Is the branch that is responsible of study all the creatures that live within the marine environment. The last one of this section is Physiology, that is the study of the functions of living beings and is the branch that study the respiratory, reproductive, nervous system, among other systems.

The second section begins with the biology that study biological heritage which is transmitted from generation to generation and is centered in the study of genes formed by segments of DNA and RNA, this biology is Genetics. The second is Zoology. Is the branch that is responsible for study of animal life. Also, we biologists study the plants. The biology that study the plants is botany, through it we can classify, describe, identify and learn about reproduction, morphology or phisiology of the natural beings of the plant world. Furthermore, another science of biology is Ecology that studies the relationship of living beings on the planet with their natural habitat. By last, Microbiology is the study of microorganims, which are the smallest living things like bacteria and fungi.

The most information that you saw above is from http://education.onehowto.com/article/what-are-the-main-branches-of-biology-and-their-definition-1598.html

Introduction

Hello guys, my name is Paola Joan Ortiz Berríos. I am a student from the University of Puerto Rico at Cayey. I am doing a bachelor degree in natural sciences with a concentration in biology. The past semester I did a blog where I expressed my opinion about some themes, but this semester I will write about some themes related to biology. Finally, I hope that you can learn more about biology and that this blog help to you to do your homework or another work with the information that I will post here.