Nutrition+&+Homeostasis

Jack Tamayo, Miri Nishikawa, Lindsey Williams, Haley Joyner, Madi Feist

1) **Ingestion**- Nutrients are taken in 2) **Digestion**- Food macromolecules are broken down so they're small enough to be absorbed by cells. 3) **Absorption**- Nutrients are transferred into the circulatory system by active transport, passive diffusion, endocytosis, or facilitative diffusion. 4) **Elimination**- Undigested materials are disposed
 * Life Process of Nutrition:**


 * How Nutrition Depends on Depends on Other Life Processes:**

Nutrition is the process of obtaining and processing food. Autotrophs are organisms that are able to feed themselves through either photosynthesis or chemosynthesis. Heterotrophs are organisms that obtain their food by consuming other organisms. There are four steps in nutrition: Ingestion, Digestion, Absorption and Elimination.

Three Examples: 1) **Skeletal system**- Teeth are part of the skeletal system and start the process of breaking down food (digestion). 2) **Circulatory system**- All cells depend on the circulatory system for nutrients and the transport of sugars and proteins. 3) **Excretory system-** Excretion is the process that removes the waste products of digestion and metabolism from the body. It gets rid of by-products that the body is unable to use, many of which are toxic and incompatible with life. 4) **Muscular system-** Nutrition depends on the muscular system to help break food down and move it through the systems

Nutrition is the provision to cells and organisms the materials necessary (in the form of food) to support life. For organisms that can't create their own food (heterotrophs), there are four different ways to obtain food: holozoic nutrition (food is taken into a specialist digestive system and broken down into small pieces to be absorbed), saprotrophic (organisms feed on dead remains of other organisms), parastic (organism obtains food from a host, with the host receiving no benefit from the parasite), and mutualism (a symbiotic relationship between the organisms, with each contributing and benefitting from each other). Digestion is what allows organisms to absorb and make use of nutrients and comes in four types: extracellular digestion, intracellular digestion, mechanical digestion, and chemical digestion.
 * How Organisms Accomplish Nutrition (Lindsey):**

Unicellular Organism: AMOEBA, a freshwater organism that uses intracellular digestion

-two pseudopods (the little waves things on the end) stick out and engulf the food into a vacuole. To actually digest the food, the amoeba releases lysosomes that attach to the food vacuole, which then secrete enzymes. The pH increases and the food is absorbed and circulates throughout the cell -the vacuole goes away from water loss

Animals: EARTHWORM

-it is just a long straight tube that goes from one end to the other -the earthworm aerates the soil by going through it, so the mouth is able to ingest the decaying organic matter along with other nutrients room the soil -the food is stored in the crop and ground up in the gizzard -the food is absorbed in the intestine, just like humans

Plant: VENUS FLY TRAP, a carnivorous plant

-plants are able to get glucose from photosynthesis, but they have nutritional requirements as well. -usually plants absorb nitrogen, which is a key component of proteins, from soil by using their vascular tissue and roots, but the Venus fly trap lives in an acidic and wet environment that kills off bacteria that cause decay and is therefore very nitrogen deficient, so it must actually eat other insects. It has an adaptation that traps an insect inside its leaves. Enzymes are released to digest the insect over a period of several days, meeting its nutritional requirements.

__**1) Carnivorous Plants-**__ Live in nutrient poor soils. they have adapted to catch and digest small animals as a supplemental source of soil nutrients. __How nutrition is accomplished-__ Nutrition is accomplished by eating the small animals in an addition to soil nutrients. __One benefit of the adaptation-__it serves as a supplementary source of soil nutrients, such as nitrogen, without being in nutrient rich soil! __One 'tradeoff" that has resulted from the adaptation-__ one trade off is that is cost more energy to make the special trapping leaves in order to be able to actually trap the animals than it would for a normal plant. __**2) Gastrovascular Cavity-**__ The cavity has only one opening tot he environment. Food goes in and waste comes out that same opening. this is also know as the two-way digestive tract. __How nutrition is accomplished-__ The gastrovascular cavity is essentially an empty space in the organism that is surrounded by tissue. food is brought into the cavity. The tissue surrounding the cavity secretes enzymes to enable digestion. nutrients are then absorbed directly by the cells surrounding the cavity and distributed to the rest of the organism through diffusion. There are very few tissues. __One benefit of the adaptation-__ one benefit is it is a faster transmission of nutrients throughout the body. __One 'tradeoff" that has resulted from the adaptation-__ a trade off is that the animal can not eat at anytime it wants to because it has to regurgitate. __ **3) One Way Digestive System**- __ food enters the mouth, passes through the rest of the digestive system and excreted throughout the anus. __How nutrition is accomplished-__ nutrition is accomplished through the physical and chemical digestion of food As it goes through the mouth and makes its way to the anus. __One benefit of the adaptation-__ one benefit is it allows the animal's body to absorb large amounts of the needed substance in foods. __One 'tradeoff" that has resulted from the adaptation-__ one trade off is that is takes longer for the transmission of nutrients throughout the body. MAMMALS
 * Three Nutritional Adaptations in Different Lineages of Multicellular Organisms:**


 * Microvillus Diagram:**

Mammals have projection on their epithetlial cells that increase the cells surface area, allowing for much more efficient absorption of nutrients, these projection are called microvilli. There are a network of blood vessels and lymphatic vessels located on the interior of the microvilli. Nutrients are picked up by blood and taken to any cell in the body that may them.
 * Why Nutrients Move Into the Blood:**

Substance absorbed at another location: Lipid- soluble components such as aspirin are absorbed in the stomach

Mircrovilli utilize other organs in digestion: pancreas-controls pH, liver-secretes bile, stomach-begins digestion (creates chyme).

After carbohydrates, proteins, and lipids are broken down into glucose, amino acids, and fatty acids, respectively, they're absorbed through microvilli. Glucose and amino acids, since they're water-soluble, are absorbed into the blood stream, while fatty acids are absorbed into the lymphatic system.
 * How Different Nutrients are Transported in the Circulatory System:**

The digestive system uses many organs and interacts with many other organ systems as well. At the very start of digestion, the skeletal system, which includes teeth, is used to grind up food before it goes down the esophagus, leading from the mouth to the stomach. It also relies on the circulatory system. There are two main ways the circulatory system is needed in the digestive process: the first is the need for blood in pretty much everything the body does. About 30% of blood that is circulated from the heart goes to the gut. The second is the need for the circulatory system to transport nutrients around. In the small intestine, nutrients are absorbed into the blood stream. The circulatory system then moves these nutrients in the blood stream around the body so they get to the necessary places, and transports unnecessary nutrients away. The digestive system also relies on the endocrine system, which contains organs like the pancreas and gut. The pancreas releases insulin after eating to regulate blood glucose levels so they don't go too high or too low. Finally, the digestive system relies on the musculatory system. This system is most important for the physical digestion of food. The tongue is a strong muscle that helps break food into smaller chunks before it is swallowed to increase efficiency. Muscles also help push food down the esophagus, help churn it up in the stomach, and move it down the intestines before it is excreted.
 * How the Digestive System Depends on Other Body Systems (Lindsey):**

an example is in which peptides cause acid and pepsinogen to be released and this in turn causes more peptides to be synthesized in the stomach, which causes acid and pepsinogen to be released. -changes in the system affect the feedback loop because if you don't have a lot of peptides, then there are less acids and pepsinogen created. If there are more peptides, there is more acid and pepsinogen created. -identify the system as exemplifying positive or negative feedback and justify your identification- this is a positive feedback because the more you put in, the more is synthesized thus creating a positive relationship. this is positive because an increase in pepsinogen causes an increase in peptides where in negative feedback as pepsinogen increased, peptides would decrease.
 * Example of Regulatory Feedback Loop That Involves the Digestive System:**

Acid Reflux: irritates and swells the mucous lining of the throat, esophagus, and stomach; it can form ulcers; caused by throat failure in the lower esophageal sphinxter; treatments include mecation that reduce the concentration of stomach acid. Lactose Intolerance: lactase deficiency; the inability to digest lactase; it cannot be absorbed by wall of small intestine, and passes intact to colon; carries must avoid dairy.
 * Two Examples of Disruptions to the Digestive System:**