Extreme Biology

by Jackie (AP Biology)

Form fits function is a very important theme in Biology. It can unify many different parts of life and yet also uniquely make them different. There are many different examples of how form fits function that you can see all throughout life. When you look at organisms, rarely will they ever have a structure that will hurt their ability to survive. Every structure in an organism’s body was created for a purpose, a function. Their specific forms and structures of their physical appearance, or their internal appearance go hand in hand with their specific function, to help them to be able to survive in their environment.
 
Molecular

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The molecular structure of proteins is very key into what the function of the protein actually is. Proteins are polymers of amino acids joined together by peptide bonds. There are 20 different amino acids that make up essentially all proteins on earth. Each of these amino acids has a specific design composed of a central carbon atom, hydrogen, a carboxyl group, an amino group, and a side chain or “R” group. The “R” group is what the most important part of the structure for the function. The side chain of the amino acid is very specific and is what distinguishes one amino acid from another. All amino acid structures are the same except for the “R” group. Therefore, whatever the “R” group is, will dictate the specific function of that protein. This causes the variation between all the amino acids, and what their specific purpose is.

Also on the structure of proteins, one or more polypeptide chains twist and form into a 3 dimensional shape to form a protein. The unique shape of the protein determines its function. For instance, structural proteins such as collagen and keratin are fibrous and stringy and on the other hand, some proteins are folded and compact like hemoglobin. As you can see in this picture, the protein (in this picture it is GFP) is slightly coiled and rounded.

Cellular

The Cellular importance in form fits function can be seen in the structure of a cell. Plant and animal cells contain many organelles that are necessary for the cell to perform necessary functions. For example, the structure of the Endoplasmic Reticulum (ER) goes hand in hand with what its specific function is. The endoplasmic reticulum structure has many membranous tubules and flattened sacs surrounding the nucleus that connects with the nuclear membrane and runs throughout the cytoplasm. The rigid outside of the ER allows for a greater surface area. This surface area is used primarily for protein and lipid synthesis and storage in the cell. It also provides a pathway for molecule transport inside the cell. The rough ER has many ribosomes attached to it. This allows for the ribosome’s to make proteins to be exported out of the cell. In contrast the smooth ER does not contain these ribosomes, and don’t make protein but instead makes lipids, hormones, and steroids. The membrane of the endoplasmic reticulum is folded, which is what allows for the greater surface area.

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Another part of the cell is the Cytoskeleton. The cytoskeleton is important part that holds the cell together and enables it to keep its shape. The structure of the cytoskeleton is essential to how it supports and creates the shape and mobility to cells. There are three very important fibers when it comes to this structure. Microtubules are made from tubulin. Any biology student will recognize microtubules in being in the most important part of the separation of cells during cell division. There is also are in cilia (in the picture) and flagella, which help in the movement of particles. The second part is the microfilaments which are made from actin, and are important in the contraction of your muscles. Last, intermediate filaments are made from keratins (protein) and function for the shape and position of organelles in the cell. Without these three important fibers, the cytoskeleton would not be able to provide a structure for the cells.

Organismal

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Obviously human organ systems are essential to our survival. Being able to understand the structure of these organ systems can explain how the organ systems work. For example, one of the most important systems in your body is the circulatory system, which is based out of the heart. The structure of the heart contains four chambers that circulates blood by rhythmic contraction.  The heart pumps oxygenated blood from the left ventricle out to the aorta and there it goes through arteries to feed the organs, muscles, and tissues of the body. The veins (vena cava system) then returns deoxygenated blood from the body to the lungs for oxygen. The blood then enters the heart in the right atrium through to the right ventricle, and flows back to the lungs for oxygen. Now, the blood has completed one cycle through the whole entire body.

Obviously, this is essential to our life and it is important that the structure of our heart can perform these functions. A lot of pressure is put onto the left ventricle to pump the blood, so its structure must be able to withstand it.  The structure of the left ventricle is important and helpful in the way that it is the thickest AND the most muscular part of the heart.  This makes sense functionally because the left ventricle is the portion of the heart that needs to pump the blood into the aorta and to the rest of the body. This is structurally designed to fit its function. The right ventricle is smaller and less muscular because it only pumps blood a short distance to the lungs for some more oxygen, so it makes sense that its structure fits its function as well. 

Population

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The population aspect of the theme Form fits Function deals with the interaction between organisms of the same species.  Communication between species in an environment can happen in many ways, but one crucial way is by visual communication. The main goal for an organism is to be able to survive and reproduce. In order to sexually reproduce, the organism needs a mate. The way they do this is fascinating. More specifically, a male peacock’s feather display shows to the female that he is willing to mate. It in turn is the female’s response on whether she would like to or not. What attracts the female to the male is sometimes its dance or “courtship ritual” or its feathers. The feathers of the peacock are what make it so attractive, because they are very colorful and can form patterns that are appealing to the female. Essentially, the structure of the feathers and the way they are displayed are for the function of attracting its mate.

The population aspect of the theme Form fits Function deals with the interaction between organisms of the same species.  between species in an environment can happen in many ways, but one crucial way is by visual communication. The main goal for an organism is to be able to survive and reproduce. In order to sexually reproduce, the organism needs a mate. The way they do this is fascinating. More specifically, a male peacock’s feather display shows to the female that he is willing to mate. It in turn is the female’s response on whether she would like to or not. What attracts the female to the male is sometimes its dance or “courtship ritual” or its feathers. The feathers of the peacock are what make it so attractive, because they are very colorful and can form patterns that are appealing to the female. Essentially, the structure of the feathers and the way they are displayed are for the function of attracting its mate.

Community

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The community aspect deals with the interaction between organisms of different species. This goes hand in hand with the concept of mutualism. Mutualism is the relationship between any two species that benefits both species. An example of mutualism is within coral reefs. More specifically, the relationship between the coral that forms the reef and the dinoflagellates is a mutualistic relationship. The dinoflagellates are benefited because of the structure of the coral. The coral (polyp) is basically a hollow cylinder fringed on top with small tentacles. The tentacles capture small organisms and sweep it into the cylinder where it is digested. Between the cells of the coral polyp cylinder are the dinoflagellates, which are single celled green algae. This is where the mutuality relationship lies. The polyp sweeps organic material from the water (with its tentacles) and metabolizes this material forming carbon dioxide and nitrogenous wastes. The dinoflagellates use the carbon dioxide and nitrogenous wastes in photosynthesis to form oxygen that is used by the coral polyps as well as the dinoflagellates in their metabolism.

Biosphere

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Geographic regions of the earth that have many ecosystems are known as biomes. A type of biome that everyone knows is a tropical forest. Tropical forests hold the greatest diversity of species. These are found everywhere- Africa, Asia, South America, and many other places. If they are near the equator they are rainforests, but in other areas that have dry seasons there just typical dry forests. Rainforests are very large in size and have thousands of tall trees that form a very thick covering. Because of this, not a lot of sunlight can reach through, leaving not a lot of life growing on the ground. Rainforests are structured by many layers including the overstory, canopy, understory, shrub layer, and ground level. The canopy makes up the overstory, and it covers so much space that much sunlight can reach through, leaving not a lot of life growing on the ground. This is important, because the canopy provides shelter, food, and protection from predators.

The canopy cover is so large that it provides a lot of surface area for photosynthesis to occur. When the sunlight is captured by the leaves, its converted into simple sugars, and leaves when the leaves or fruit is eaten by other organisms that decided to live in the forest. The humid climate adds a lot of water being produced which is necessary for survival. The sun shines all the time in a tropical rainforest, leaving no food shortage in this ecosystem. An immense amount of nutrients (water and carbon most important) are found within tropical rainforests, which makes it appealing for so many species to live there. As you can see, the many parts of the rainforest fit its specific function. The canopy’s large leaves and long span provides a great surface area for photosynthesis to occur. Along with that and the stems and roots of trees, it provides a home and a source of protection for the species that live there. Overall, every part of the forest provides a positive atmosphere for multiple species to live in.

This entry was posted on Thursday, April 24th, 2008 at 10:05 am and is filed under AP Biology, Themes in Biology. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.