Glucose, diffusion and diabetes:
In order to get nutrients to cells, cells must obtain and use glucose (Frolich pg.1). As discussed in the previous topic, our cells need oxygen for cell respiration in order to make ATP, which is used to power all the reactions of a cell’s metabolism (Frolich pg.1). Therefore, glucose is the product that gets burned or combined with oxygen in the cellular respiration process (Frolich pg.1). The main processes that make ATP with glucose as a principle reactant are glycolysis and the Kreb’s cycle (Frolich pg.1).
First, glucose diffuses through a special protein pore on the cell membrane (Frolich pg.1). After this process, insulin is the protein which is secreted by the pancreas into the blood (Frolich pg.1). This process usually occurs after eating a meal (Frolich pg.1). Insulin is responsible for stimulating the cells in order for them to take up glucose and store it as glycogen, or use it in cellular metabolism (Frolich pg.1).
Glycolysis is considered the metabolic pathway by which a 6-carbon glucose molecule is oxidized by two molecules of pyruvic acid (Mader). This process allows the generation of high-energy molecules such as ATP used as cellular energy (Mader). This energy acts as sources for anaerobic and aerobic respiration (Mader).
In order to get nutrients to cells, cells must obtain and use glucose (Frolich pg.1). As discussed in the previous topic, our cells need oxygen for cell respiration in order to make ATP, which is used to power all the reactions of a cell’s metabolism (Frolich pg.1). Therefore, glucose is the product that gets burned or combined with oxygen in the cellular respiration process (Frolich pg.1). The main processes that make ATP with glucose as a principle reactant are glycolysis and the Kreb’s cycle (Frolich pg.1).
First, glucose diffuses through a special protein pore on the cell membrane (Frolich pg.1). After this process, insulin is the protein which is secreted by the pancreas into the blood (Frolich pg.1). This process usually occurs after eating a meal (Frolich pg.1). Insulin is responsible for stimulating the cells in order for them to take up glucose and store it as glycogen, or use it in cellular metabolism (Frolich pg.1).
Glycolysis is considered the metabolic pathway by which a 6-carbon glucose molecule is oxidized by two molecules of pyruvic acid (Mader). This process allows the generation of high-energy molecules such as ATP used as cellular energy (Mader). This energy acts as sources for anaerobic and aerobic respiration (Mader).
The Kreb’s cycle, also known as the citric acid cycle, is very important in all living cells (Mader). This cycle is a series of enzyme-catalysed chemical reactions that use oxygen as part of cellular respiration (Mader). In aerobic organisms, the Kreb’s cycle is part of a metabolic pathway involved in the chemical conversion of carbs, fats, and proteins into carbon dioxide and water (Mader). These conversions result in usable energy for a cell (Mader). The citric acid cycle also provides precursors for many compounds, and some of its reactions are needed even in cells performing fermentation (Mader).
Every human body needs more than just sugar in order to live (Frolich pg.1). Though our body produces many things that make our body run smoothly, one thing that it doesn’t produce is essential amino acids (Frolich pg.1). These essential amino acids are needed in order to make proteins in our body (Frolich pg.1). Essential amino acids can come from different food sources, vitamins or minerals (Frolich pg.1). In fact humans can only produce half (10 out of 20) of essential amino acids (University). Failure to obtain enough of even 1 of the 10 essential amino acids can result in degradation of the body’s proteins and muscles (University). This is so important because, unlike fat and starch, the human body can’t store an excess of amino acids for later use, and must be in the food we eat every day (University). The 10 amino acids that we can’t produce are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine (University).
Diabetes is a metabolic disorder that is characterized by hyperglycemia (Mader). Hyperglycemia is high blood sugar, and is just one of the signs of diabetes (Mader). The World Health Organization recognizes three main form of diabetes (World). These types include Type 1, Type 2, and gestational diabetes, which occurs only during pregnancy (World). All forms of diabetes are due to the beta cells of the pancreas being unable to produce a sufficient amount of insulin in order to prevent hyperglycemia (World).
Type 1 diabetes usually occurs because of the autoimmune destruction of the pancreas beta cells that produce insulin (World). Type 2 is characterized by tissue-wide insulin resistance, and can sometimes progress because of the loss of beta cell function (World). Similar to Type 2 diabetes, gestational diabetes occurs when the hormones of pregnancy cause insulin resistance in women who are genetically predisposed to developing this condition (World).
Unfortunately Type 1 and type 2 diabetes are incurable chronic conditions (World). Although this is true there are insulin treatments that became medically available in 1921 (World). Today, these treatments are usually managed with a combination of dietary treatment, tablets, and insulin supplementation (World). Fortunately, gestational diabetes is usually resolved upon delivery of a child (World).
The digestive system includes a series of hollow organs that lead from the mouth to the anus (National). In the inside of the mouth, stomach and small intestine is a lining called mucosa (National). Mucosa helps digest food through tiny glands that produce digestive juices (National). The liver and the pancreas are what produce digestive juices that are needed in the intestines (National).
Digestion is especially important because, when we eat food, they aren’t initially in a form that the body can use as nourishment (National). Our food and drinks have to be changed to smaller molecules of nutrients before they can be absorbed into the bloodstream and carried to cells throughout the body (National). The actual process of digestion is when food and drink are broken down into their smallest parts so the body can use them to build and nourish cells and provide energy for the body (National). Digestion involves the mixing of food, its movement through the digestive tract, and the chemical breakdown of large molecules of food into smaller molecules (National). Digestion begins in the mouth, when we chew and swallow, and is completed in the small intestine. The chemical process also slightly varies for different kinds of food (National). The large, hollow organs of the digestive system contain muscle that enables their walls to move. The movement of organ walls can push food and liquid and also mix the contents of each organ.
Type 1 diabetes usually occurs because of the autoimmune destruction of the pancreas beta cells that produce insulin (World). Type 2 is characterized by tissue-wide insulin resistance, and can sometimes progress because of the loss of beta cell function (World). Similar to Type 2 diabetes, gestational diabetes occurs when the hormones of pregnancy cause insulin resistance in women who are genetically predisposed to developing this condition (World).
Unfortunately Type 1 and type 2 diabetes are incurable chronic conditions (World). Although this is true there are insulin treatments that became medically available in 1921 (World). Today, these treatments are usually managed with a combination of dietary treatment, tablets, and insulin supplementation (World). Fortunately, gestational diabetes is usually resolved upon delivery of a child (World).
This disorder can also cause many complications, sometimes acute, and others severe (World). Some of the acute complications include hypoglycemia, ketoacidosis, and nonketotic hyperosmolar coma (World). Some of the long-term complications include cardiovascular disease, which diabetics are twice as like to get, retinal damage that can lead to blindness, and chronic renal failure (World). Other complications include nerve damage, erectile dysfunction, micro-vascular damage, and poor healing of wounds (World).
Digestion:
Digestion is simply the process of metabolism whereby a biological entity processes a substance chemically and mechanically converts a substance for the body to use (Mader). During this process nutrients enter the body in the form of food (Frolich pg.2). These nutrients diffuse across the wall of your gut and into the blood, and travel through the bloodstream, and eventually diffuse into the cells (Frolich pg.2).
The digestive system includes a series of hollow organs that lead from the mouth to the anus (National). In the inside of the mouth, stomach and small intestine is a lining called mucosa (National). Mucosa helps digest food through tiny glands that produce digestive juices (National). The liver and the pancreas are what produce digestive juices that are needed in the intestines (National).Digestion is especially important because, when we eat food, they aren’t initially in a form that the body can use as nourishment (National). Our food and drinks have to be changed to smaller molecules of nutrients before they can be absorbed into the bloodstream and carried to cells throughout the body (National). The actual process of digestion is when food and drink are broken down into their smallest parts so the body can use them to build and nourish cells and provide energy for the body (National). Digestion involves the mixing of food, its movement through the digestive tract, and the chemical breakdown of large molecules of food into smaller molecules (National). Digestion begins in the mouth, when we chew and swallow, and is completed in the small intestine. The chemical process also slightly varies for different kinds of food (National). The large, hollow organs of the digestive system contain muscle that enables their walls to move. The movement of organ walls can push food and liquid and also mix the contents of each organ.
Movement of the esophagus, stomach, and intestine is called peristalsis (National). The muscle of the organ produces a narrowing and then pushes the narrowed portion slowly down the length of the organ (National). These waves of narrowing push the food and fluid in front of them through each hollow organ (National).
Next, the first major muscle movement occurs when food or liquid is swallowed. Although we are able to start swallowing by choice, once the swallowing process begins, it becomes involuntary and proceeds under the control of the nerves (National). Then the esophagus is the organ into which the swallowed food is pushed (National). At the junction of the esophagus and stomach, there is a ring-like valve closing the passage between the two organs. However, as the food approaches the closed ring, the surrounding muscles relax and allow the food to pass (National).
The food is now able to enter the stomach (National). The stomach is responsible for three mechanical tasks (National). The first task of the stomach includes storage of the swallowed food and liquid (National). This requires that muscle of the upper part of the stomach to relax and accumulate large volumes of swallowed material (National). The next job of the stomach is to mix up the food, liquid and digestive juices into a mixture known as chyme (National). The lower part of the stomach is responsible for mixing these materials by muscle action (National). The third responsibility of the stomach is to empty its contents into the small intestine in order for waste removal (National).
Next, the first major muscle movement occurs when food or liquid is swallowed. Although we are able to start swallowing by choice, once the swallowing process begins, it becomes involuntary and proceeds under the control of the nerves (National). Then the esophagus is the organ into which the swallowed food is pushed (National). At the junction of the esophagus and stomach, there is a ring-like valve closing the passage between the two organs. However, as the food approaches the closed ring, the surrounding muscles relax and allow the food to pass (National).
The food is now able to enter the stomach (National). The stomach is responsible for three mechanical tasks (National). The first task of the stomach includes storage of the swallowed food and liquid (National). This requires that muscle of the upper part of the stomach to relax and accumulate large volumes of swallowed material (National). The next job of the stomach is to mix up the food, liquid and digestive juices into a mixture known as chyme (National). The lower part of the stomach is responsible for mixing these materials by muscle action (National). The third responsibility of the stomach is to empty its contents into the small intestine in order for waste removal (National).
Food is then digested in the small intestine and dissolved into the juices produced by the pancreas, liver and intestine (National). The contents of the intestine are then mixed and pushed forward to allow for further digestion (National). In the last process, all the digested nutrients are absorbed through the intestinal walls (National). The waste products of this process include anything from undigested parts of food (fiber), and older cells that have been shed from the mucosa (National). All of these materials combine and end up in the colon and stay for approximately one or two days before the feces are secreted (National). This entire complicated process is known as digestion.
Nutrition and diet:
Nutrition includes all the good parts we get from the food that we consume (Unicef). Diet is the sum of food consumed by an organism or group (Unicef). Eating the right foods that are nutritious, and maintaining a healthy diet are ways to improve and sustain life. Food is made up of several different types of nutrients that contribute to nutritious food (Unicef). These nutrients include carbohydrates, fats, proteins, vitamins, minerals and water (Unicef).
The macronutrients carbohydrates, fats, and proteins are the most important is sustaining life (McKinley). Macronutrients are what provide calories or energy for the body (McKinley). Nutrients are needed for growth, metabolism, and many other body functions (McKinley). The term ‘macro’ means large in which means these nutrients are needed in large amounts (McKinley). Each macronutrient provide a different amount of calories needed for the body (McKinley). Carbohydrates and protein provide 4 calories per gram while fat provides 9 calories per gram (McKinley).
Carbohydrates are the macronutrient that we need in the largest amount (McKinley). According to the Dietary Reference Intake, 45-65% of calories should come from carbohydrates (McKinley). This is the reason why it is so important not to go on low carb diets, because they are so important to many bodily functions (McKinley). Carbohydrates are the body’s main source of fuel, and are easily used by the body for energy (McKinley). All of the tissues and cells in our body can use glucose for energy, and carbohydrates are needed by the central nervous system (McKinley). The kidneys, brain, muscles and the heart all need carbohydrates in order to function properly (McKinley). Carbohydrates can be stored in the muscles as glycogen, or in the liver and later used for energy (McKinley). Carbohydrates are also important in intestinal health and waste elimination (McKinley). Carbohydrates are mainly found in starchy foods such as potatoes or grains, but can also be found in fruits, milk, and yogurt (McKinley). Foods such as veggies, beans, nuts, cottage cheese, and seeds also contain carbohydrates but in smaller amounts (McKinley).
Protein is another macronutrient important to survival (McKinley). According to the Dietary Reference Intake, about 10-35% of calories should come from protein (McKinley). Protein is usually found in meats, poultry, fish, cheese, milk, nuts, and legumes (McKinley). Proteins are responsible for growth, tissue repair, immune function, making essential hormones and enzymes, providing energy when carbohydrates are not available and preserving lean muscle mass (McKinley). When we eat foods that contain protein, our body breaks it down into amino acids (McKinley). Protein that come from animal sources contain all the essential amino acids that our body cannot produce, and this is why sometimes it is hard to be a healthy vegetarian (McKinley). 
Lastly, some fat is essential for survival (McKinley). Fats normally have a bad reputation for causing weight gain, but are still important in order to live (McKinley). Again, according to the Dietary Reference Intake, 20-35% of calories should come from fat (McKinley). Fat is responsible for normal growth and development (McKinley). Fat is also the most concentrated source of energy (McKinley). Fat is also important in absorbing certain vitamins such as A, D, E and K which provide a different responsibility in the overall function of our body (McKinley). Fat also provides a cushion for organs, maintains cell membranes, and provides taste, consistency and stability to foods (McKinley). Fat is found in many foods such as poultry, meat, nuts, milk products, oils, lard, butter, margarine, fish, salad dressings, and grain products (McKinley). There are also three main types of fat, including saturated, unsaturated, and trans fat (McKinley). Saturated fat is found in foods such as meat, butter, lard and cream, whereas trans fat is found in baked goods, snack and fried foods, and margarine (McKinley). Unsaturated fat is the ‘good’ fat of the three, and is usually found in olive oil, avocados, nuts and canola oil (McKinley). Unsaturated fat has even been shown to reduce the risk of having a heart attack (McKinley).
Macronutrients are important for survival, but micronutrients are just as important (McKinley). Micronutrients are nutrients that our bodies need in smaller amounts (McKinley). These micronutrients include vitamins, and minerals (McKinley). Our bodies also need water for survival; approximately 6-8 glasses a day (McKinley). Vitamins and minerals are essential to human health, but do not give you energy (McKinley). Although they do not give you energy, they assist in energy-yielding reactions and promote body growth and development (McKinley). Each vitamin and mineral plays a different role in each function of the body, and together keeps us alive (McKinley).
If all these nutrients are not consumed, our body becomes malnourished (Unicef). If a person suffers from malnutrition they can be more likely to obtain diseases, and it can also affect different functions of the body such as the brain, eyesight, organs, height, weight, and the formation of body parts (Unicef). Many problems with malnutrition can occur due to the lack of vitamins, minerals, and clean drinking water (Unicef). When a person lacks vitamins and minerals, they suffer from micronutrient malnutrition (Unicef). Malnutrition occurs most frequently in underdeveloped countries, and it is believed that nearly one third of children in developing countries are malnourished (Unicef). In the developing stages of life, breast milk can be a vital source of micronutrients for growing babies, but sometimes an improved diet for an adult can be unattainable (Unicef).
Remember food? :
Food not only brings long-term health to our lives, but can bring a spiritual and cultural base back into our diet (Frolich pg.3). Food can also bring long-term health into farming and agricultural ecosystems (Frolich pg.3). Though internally humans are very similar, cultures can change people decision on the types of foods they consume. In the United States, our foods may be primarily imported (Frolich pg.3). Different cultures, and even different homes vary on what individuals consume (Frolich pg.3). Some cultures provide more home-cooking with local fresh ingredients from a garden, rather than from a grocery store like many in the U.S. (Frolich pg.3).
Nowadays food is usually found and produced in factories, instead of farmed (Frolich pg.3). Unfortunately this type of produce is not concerned about long-term health issues of consumers, or long-term productivity of the land (Frolich pg.3). Factory production only has to follow government regulations, not local ones, and many people in the U.S. don’t even know where their food comes from, or where it is raised (Frolich pg.3).
Frolich, Larry. “Food Nutrition powerpoint” pg.1-5
Mader, Sylvia. “Human Biology 10th edition”. 2008
McKinley Health Center. “Macronutrients” http://www.mhc.uiuc.edu/Handouts/macronutrients.htm . 2007
National Digestive Diseases Information Clearinghouse. “Digestive system” http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/
UNICEF New Zealand “What is nutrition?”. 2007
World Health Organization. http://www.who.int/en/. 2007
Picture citations:
Glycolosis - http://staff.jccc.net/PDECELL/cellresp/glycolysis.gif
Krebs cycle - http://www.ithaca.edu/faculty/pmelcher/krebs_cycle.gif
Amino acid chart - http://www.geisswerks.com/ryan/veg/veggie_guide_files/image002.gif
Digestion - http://www.med.miami.edu/med/gastroenterology/images/digestion_med.jpg
Type II diabetes - http://www.soylabs.com/img/diabetes_type2.jpg
Digestive system II - http://www.amwa-doc.org/images/digestive.jpg
Complex carbohydrates - http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/19529.jpg
Fiber - http://medicineworld.org/images/blogs/fiber-diet-761055.jpg
Protein - http://www.drpbody.com/images/meatpoultryfish.gif
Saturated fat - http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/19513.jpg
Vitamins - http://schoolclub.taps-nodes.co.za/printable/images/food_table.gif
Food factories - http://businessnetwork.theage.com.au/verve/_resources/430_biznet_nov18.jpg
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