Biochemistry

keck.usc.edu

BIOCHEMISTRY

All organisms have cells with DNA in them. Where there is DNA, there is cell replication. All of the organisms have an enzyme-based digestive system. All of the cells contain a nucleus, cell wall, etc. The respiratory systems of the organisms use a gas exchange with O₂ and CO₂. The earthworm in particular uses diffusion to breathe. When the integumentary system of the earthworm is moist, it allows the earthworm to diffuse O₂ and CO₂.All of the organisms perform homeostasis to keep alive. Using glucose or carbohydrates for "fuel". Also supporting the fact on how everything is made up of molecules and atoms. Organisms like the frog or the rat use salivary amylase to help digest and break down foods. Afterwards extracting nutrients like carbohydrates out of the small intestine.

The Rat

www.animalresearch.info

INTEGUMENTARY

The rat has an epidermis, dermis, and subcutaneous layer of skin. There is a coating of fur, uncovered skin (hands) and nails. Rats have hair all over their body to conserve heat. Nails are mainly for clawing and catching prey. compared to the other organisms, this is the only organism to have hair.

CIRCULATORY
The rat has an lymphatic system much like the humans. Compared to the other organisms, this is the only organism to have an four chambered heart, therefore making the most efficient.  The circulatory system performs both pulmonary and systemic flow; basically being a double circulation. In other words, the blood circulates between the lungs and heart (pulmonary) and flows between the heart and rest of the body (systemic). There are blood, blood vessels. a heart, and arteries included in this system. This is the only organism to have a pulmonary/systematic blood flow, and an four chambered heart.

DIGESTIVE
This chemical digestive system includes a mouth, esouhphagous, pharynx, stomach, small/large intestine, liver, pancreas, colon, rectum, and anus. Teeth and salivary amylase do a big job of breaking down food for this organism. Being the only organism to have teeth,  a gall bladder, a pancreas, spleen, and a colon. The rat's digestive system is closest to the human, for they are both mammals. The rat has an approximately 1 foot long small intestine. Having a long intestine is an advantage. It allows the organism to absorb more nutrients. Unlike the frog, who has an approximately 2 inch small intestine, clearly cannot absorb as much nutrients as the rat can.

www.biology.iastate.edu

SKELETAL
Like the frog and human, the rat has an axial skeleton with full limb bones and movement. This is the only organism to have a ribcage. Having a ribcage may be an advantage, for the ribcage may protect internal organs. The rat has nails/claws for grip, prey, etc.

MUSCULAR
The rat has ligaments, cartilage, tendons, and muscles just like humans do. Contracting,flexing, and extending muscles assist in movement just like any of the other animals. Cartilage assists in cushioning and impacts.

The Frog.

INTEGUMENTARY

The integumentary system of the frog allows it to protect with camouflage, breathe underwater, and stay moist when it is on land. The frog contains a stretchy skin that sometimes changes color to control how much heat to absorb, regulating body temperature. Consisting of an epidermis, dermis, and subcutaneous respiration layer, the frog is suited for any environment. The Epidermis is mostly used for protection. The Dermis contains poison and mucus, used for water and gas exchange The Subcutaneous layer consists of nerves just like the humans.

DIGESTIVE

The digestive system consists of an esophagus, pharynx, stomach, small/large intestine, a rectum, and a cloaca. The frog does not have teeth, therefore creating a slow digestive system. For example, during dissection, we had made an incision into the stomach, and extracted full bug bodies and pieces. The main job of the digestive system is to break down prey to molecules; then absorbed into the body. Saliva, muscle contractions, and enzymes perform a major job for the breakdown of food. Absorbing the nutrients located in the less than 2-3 inch small intestine.

SKELETAL

The frog has an axial skeleton with a spinal cord, skull, and sternum. The frog also has full limb bones and movement, similar to the human and rat. The frog does not have a ribcage; for it would most likely break on impact from jumping. 

www.docstoc.com

CIRCULATORY

The circulatory contains a heart, veins, blood vessels, and arteries. It has a closed circulatory system with a heart of three chambers. The heart has two auricles, and one ventricle. Disadvantages of a three chambered heart have said to been because of the fact on how oxygenated blood is mixed with blood from the tissues. Compared to a mammal's lungs; where the output-oxygenated blood is separated with non-oxygenated blood. The heart pumps blood to the head, the lungs, the skin, and rest of the body. (Possibly muscular, for muscles need oxygen to function.) 

The Intestine (top) and three chambered heart. (bottom)

MUSCULAR/MOVEMENT

The frog has strong leg muscles for leaping, and excellent abdominals for landing. Frogs most likely generate much power to jump, for they can jump up to 3 feet. Muscle contractions help create this exploding jump. If they may, frogs can walk. It is usually too slow, therefore that energy is much used more efficiently in jumping. 

Advantages/Disadvantages

CRAYFISH

ADVANTAGES
Exoskeleton for protection and support. The ligament and muscles attach to the exoskeleton, providing extra support and internal organ and muscle structure. They have a nerve cord located on the ventral side of the body. Compared to the humans, the nerve cord is located on the dorsal side of the body. (The spine.) Being on the ventral side, it is more protected. If anything, the predator will attack the bottom, but ligament-filled pinchers should protect that side of the body. Having gills attached to the Crayfish's legs is an advantage as well. As the crayfish walks, water is constantly being "swished" against the legs. Not causing much energy to breathe.

DISADVANTAGES
The Exoskeleton may hinder movement. Being cold-blooded, this organism has to move to different environments to maintain homeostasis. For example, if the crayfish is cold, it must move to a different environment where it is warmer. Vise-versa, if the crayfish is too cold, it must move to a more "warmer" climate. The crayfish's exoskeleton must molt. Like a snake must replace it's skin. So if the crayfish has just molted out of it's old shell, the crayfish is vulnerable to it's predators due to growing no shell yet. A disadvantage of the gills being attached to the legs, is if any of the legs are torn off, it may decrease the breathing rate. Therefore explains the reason to have multiple legs.

EARTHWORM

ADVANTAGES
Being made up of mostly muscle, the earthworm can easily stretch, contract, and squeeze into spots. For there is no skeletal system; no bones to break! The integumentary system of the earthworm must be moist, so it may be easy, or it may be hard to live around moist or wet climates in order to breathe. The worm may not struggle to find food, for it mainly consumes soil. Therefore, soil is everywhere! This way, the earthworm may not struggle to find food.

DISADVANTAGES
Having no skeletal system, you would have a hard time to lift heavy objects, for there is no bones to support all of that muscle. Another disadvantage, the worm must keep from drying out to breathe. The worm uses diffusion to release carbon dioxide, and take in oxygen. If there is no moisture, the worm will dry out and die.

RAT 
ADVANTAGES
The rat is warm blooded, allowing it to go where it pleases, without having to worry about looking for cold or hot environments to regulate homeostasis. The rat has a four chambered heart. Having a four chambered heart gives the advantage of longer endurance; for there is more oxygen delivered to the muscles.
DISADVANTAGES
Rats are known to have Cardiac failure in their circulatory system. For example, if a rat may be too exited, the circulatory heart may become too tired, and give up. Another disadvantage of the rat includes the risk of getting parasites; due to the fur on the integumentary system. An complex digestive system results in a slow digestion. Most similar to human's digestive system.

FROG
ADVANTAGES
Having a mucus-lined, semi permeable integumentary system, in the water, the frog breathes through it's skin. It's dual respiratory system allows it to leave and enter the water whenever it wants. On the limbs, are webbed feet; assisting in swimming. The integumentary system also allows the organism to live anywhere. From the desert to the top of mountains. Since it is cold-blooded, the frog may sometimes have to burrow underground to maintain homeostasis. Surrounding itself in a cocoon made of it's shed skin. To prevent freezing, it uses glucose to keep internals flowing, as the external body may freeze solid. Much in a "Limbo" state. To get around, frogs may jump or waddle. When jumping, there are solid abdominal muscles to absorb the landing impact. The digestive system includes a variety of insects, snails, and worms. Larger frogs may choose to consume on bigger prey, such as a mouse. (If large enough.) The digestive system contains a pharynx just like the other organisms, a stomach, large and small intestine, and an cloaca.

DISADVANTAGES
The frog does not have a ribcage. Making it somewhat vulnerable to it's internals, but strong abdominals may save the internal organs. Without teeth, a slower complex digestive system may take longer than the other organisms.

*all photos taken by me*

Crayfish

CRAYFISH

Phylum: Arthropoda

DIGESTIVE SYSTEM

The crayfish's digestive system consists of a mouth, cardiac and pyloric stomach (located near the head), an digestive gland, intestine, and an anus.

 http://www.cnsweb.org/extra/digestvertebrates/GITFigures/EvolutionDigestiveSystemCrustaceanCrayfish%20F12_07.gif

This simple digestive system includes many enzymes to aid in chemical digestion. There is a cardiac stomach, located above the mouth, storing and grinding the food down. The food is then led into the pyloric stomach, transporting the food into the digestion glands to be digested. The digestive gland contains many enzymes, aiding to absorb nutrients, and break food down extensively. The Crayfish is the only organism to have more than one stomach, compared to the other organisms. The system is based on enzymes, and it is a simple digestive system, therefore this organism can consume a lot, and the digestive system is fairly quicker compared to an complex digestive system.

CIRCULATORY SYSTEM

The Crayfish has no veins, making it an open circulatory system. Similar to other crustaceans, there are two arteries from the dorsal sided heart, tracing down both Posterior and Anterior sides of the body, into tissue spaces called Sinuses. Blood pumps from the heart, through arteries, into open sinuses.

www2.gsu.edu

The Crayfish contains a three chambered heart. The vessels leading from the heart are led into a ventral sinus, collecting the blood. The blood is filtered through the heart, then is lead back towards the heart. 

SKELETAL/MUSCULAR SYSTEM

The Crayfish is the only organism to have an exoskeleton. Having an exoskeleton could be an advantage, due to the fact on how it is "armor-like". A disadvantage may be in case of anything, if the exoskeleton were to crack or break, the crayfish's internals are immediately being exposed. Compared to the Earthworm, the earthworm does not even contain a skeletal system. Although, the earthworm is almost made entirely of muscle. Compared to the Rat, Human, and Frog, these organisms contain endoskeletons, which are complete opposites when it comes to endo/exoskeletons. Again, making the Crayfish the only organism to have an exoskeleton. 

The Crayfish's muscular system includes powerful abdominal muscles to rely on movement. It also allows the organism to swim backwards rapidly and powerfully. Multiple legs also to aid in movement. Unlike other organisms, the tissues do not support the skeletal system, for the muscles line the exoskeleton, compared to muscles supporting an endoskeleton. The muscular system for the crayfish are made mostly of ligaments.

RESPIRATORY SYSTEM

The Crayfish's respiratory system uses gills. These Gills are connected to it's legs. Whenever the Crayfish walks, it uses it's legs to filter the water for respiration. The Crayfish has a water "pocket" allowing it to walk on land as well. 

The Gills have high surface area, because of the flat stacks of gills. Each plate has a spiked-like shape to extend further surface area. If you take a closer look at the Gills, each "flap" contains blood capillaries to aid in gas exchange. This respiratory design is highly efficient, for it adapts on both land on water. If the respiratory layout of this organism were to be inefficient, this organism would result in extinction; since it clearly would not be able to survive.

The Earthworm.

Phylum: Annelids

INTEGUMENTARY

The earthworm's integumentary system is similar to Human's respiratory system. It uses diffusion/osmosis to rid of carbon dioxide, and take in oxygen.

Texture : The earthworm's texture is always moist with mucus. this mucus assists with diffusion, as well as movement. Deep into the skin, there are "bristles" called Setae, giving the worm a "sticky" texture. Setae also anchor the worm's body to assist in movement.

MUSCULAR/MOVEMENT

Muscles : The Earthworm had both circular and longitudinal muscles. These muscles contract, and expand. The "expanding" movement, is caused by it's circular muscles on each segment, relaxing. making the worm thin and long. To make the worm contract and become shorter, is the second layer of muscle located from the head to tail, is underneath the circular muscles. This muscle pulls itself together, making the worm short and stiff.

Movement : This organism constantly contracts and expands to move around. On each segment, tiny bristles "Setae" help hold it down to assist in movement. Synchronizing the contractions, average worms can move up to 185 feet per hour.

DIGESTIVE SYSTEM

This organism consumes soil. Bacteria is located in the soil, therefore making it a variety of decomposed organisms/items. The Earthworm will consume soil, and release "Castings". Castings are full of nutrients that plants may use. Making Earthworms a farmer's best friend, and a vital organism to have in a food chain. (For predators like birds may consume these organisms.

Earthworms have a full digestive system. They have a mouth to eat, a pharynx and esophagus to transport the soil toward the crop. The esophagus contains calciferous glands to help break down the food. It is stored into the crop, awaiting the gizzard. The gizzard will also break down nutrients then transport them into the intestines. The intestines release fluids to assist with digestion. (This explains why our Worm was filled with dirt. For I had accidentally made an incision into the intestine while opening the Integumentary system.) Attached to the intestine are blood vessels. This way the nutrients are transported to where they are needed.

RESPIRATORY SYSTEM

The Earthworm does not have specific respiratory organs. Instead, it uses diffusion to take in oxygen, and get rid of carbon dioxide. This is also one of the reasons why this organism has to be constantly moist. (Ever wonder why there are dried earthworms on the pavement?) This is also why they live underground to prevent drying out. Studies have shown that Earthworms usually come out during the evening, because it is much cooler.

CIRCULATORY SYSTEM

Having a closed circulatory system, blood is constantly circulating. This organism has three major vessels. There is the Aortic Arches (Hearts) located in the top mid section near the head. The Dorsal Blood Vessels located on the dorsal/top side. The Ventral Blood Vessels are located on the underside/ventral side of the worm. The Ventral vessels are to transport blood to the back of the Earthworm's body, whereas Dorsal vessels are to transport blood to the front of the body. These vessels supply blood to organs.

biology.unm.edu

Advantages: Being a decomposer, this organism is much needed for an environment. Built for underground living, it's mucus covering allows for easier movement, and it feeds on dirt! Therefore, i don't think it struggles to find food. This mucus covered, skeleton-lacking annelid can squeeze into many places where organisms that have a skeleton, cannot fit.

Disadvantages:  Lacking a skeletal system, this organism may find trouble when it comes to lifting heavy objects. It is also a disadvantage because it may be easier to kill, since there is no skeleton to support. It must always stay moist, because if it dries out, the earthworm cannot use diffusion to breathe.

LE WORM VIDEO

Worm Dissection Time Lapse