04-11-07, Nutrition studies

We have nutrition, urinary system, and the nervous system to go through in terms of notes and tests within the next four weeks that are basically left for us to work with.

“Nutrition - or the lack thereof.” Food contains nutrients. The body for growth, repair and maintenance needs nutrients and the idea of “nutrients” is very broad. There are six kinds of nutrients:

Nucleic acid is not a nutrient, but rather an “informational macromolecule”. The nucleic acids are going to be the nucleotides that are used in the proteins, but they are in the form of polypeptides and so on, which can be broken down into amino acids in the stomach with the action of pepsin enzyme.

There are four types of organic nutrients and two types of inorganic nutrients. The four nutrient-types that are organic are carbohydrates, proteins, lipids, and water, where the minerals and vitamins are inorganic.

Nutrition is the science of how our bodies obtain energy, build tissue, and control body functions using materials supplied in the food we eat. Food supplies us with energy not only to do work but to generate the heat that maintains our body temperature.

To measure the amount of energy that can be obtained from food, scientists use the unit known as the calorie with a small “c,” which is very important because of the kilocalorie represented by “Calorie”. The calorie is defined as the amount of energy needed to raise the temperature of one gram of water by one degree Celsius.

Nutritionists usually refer to the energy content of food in terms of the kilocalorie or kcal, which is 1000 calories known as one Calorie. “The nutritionists, mathematicians, and academicians were all at each other's throats.”

The calories that you see listed on food labels are really kilocalories (Calories), not just calories. The basic energy need of an average-sized human is about 1500 Calories per day (or 1.5 * 10^{^6} calories). The energy requirements are dependent on work done, age, gender, etc.

Basal Metabolic Rate (BMR): the sum of the entire chemical processes that take place within an organism. Metabolism is basically the word for every chemical process taking place in some system … and so you could see that metabolism (anabolic and catabolic pathways) are going to be one of the main components of balancing some system within some larger ecology.

The Basal Metabolic Rate is equal to the number of kilocalories an animal must use in a set amount of time just to maintain life, so very “sloth-like” in nature as some of you tend to be.

The reason that these numbers are different is because this is for people that are doing “not much”. So this is not going to be the same as the required 1.5 *10^{^6} calories.

Food supplies building materials, the substances required by the cells in our body for proper growth and development. Tissue throughout the body must be repaired and replaced.

The following numbers represent an approximate number of servings that you should have each day. These servings are: fruits and vegetables (5-9), grains (6-11), dairy products (2-3), and protein-rich foods (2-3). Green leaves actually have more calcium than cow milk. “Cows produce milk, but not for you. Humans produce milk too, for human babies … not calves.”

The eukaryotes of the human body get most of their energy from carbohydrates like glucose. Now we're just going back and looking at all of the varieties of molecules and see how they apply to nutrition instead of molecular biology. In the absence of carbohydrates, your body will be using the stored lipids, and then some of the muscle energy sources.

Before your body can use carbohydrates, it has to be converted to glucose because that's the usable form for digestion and supply of energy to the cells. Excess glucose is changed to glycogen and glycogen is stored in the liver. You also have glycogen stores in your muscle tissues. Glycogen is still a carbohydrate, and if that isn't used in a certain time frame, then it will be further converted into fats for long-term energy storage.

There are three types of carbohydrates: monosaccharides which include glucose (C₆H₁₂O₆) and glucose. The disaccharides include sucrose, lactose, and maltose (and in the stomach note how we have sucrase, lactase, and maltase enzymes). The third category is polysaccharides (aren't there trisachharides?). The polysaccharides include starch, cellulose, glycogen, etc.

Construction materials for muscle, skin and blood are proteins. Proteins build everything in organisms. The regulation and obtaining of proteins is what makes up the structures, systems and processes.

There are two types of proteins: (1) structural and (2) enzymatic. This is because of the quaternary level of proteins. Bodies contain thousands of different proteins. Proteins are made from about 20 different amino acids. Of the 20 amino acids, 12 of them can be made within humans.

“Complete protein” (milk, eggs, red meat, milk products, … and most meat, some vegetables come close - like soy, which has all eight essential proteins) - contains the eight essential amino acids. There are eight “essential” amino acids that the human body cannot manufacture and construct.

It is more beneficial to eat rice with beans, because they overlap and between the two of them you get your eight essential proteins to get “complete protein”.

Most plant products lack some of the essential amino acids and are called incomplete proteins. Before our bodies can use the proteins they must be broken down into amino acids (like by the action of pepsin in the stomach juices which break down proteins). Cells can then use the amino acids to synthesize new proteins.

Lipids are fats that are important for several reasons. They are concentrated sources of energy and are used for long-term energy storage. They are responsible for storing nutrients, such as vitamin A and other fat-soluble vitamins (vitamin A is fat soluble). Lipids protect vital organs.

In our cat dissections, the kidneys were hidden in a layer of lipid. Lipids in this case help protect the organs. Lipids help our skin from drying out. Lipids are also used (phospholipids) in the cell membrane. They have the fatty-acid tails. Lipids help to insulate the body against changes in environmental temperature.

Fats are made up of glycerol and fatty acid chains. The body must first break the fats down into their basic compounds of glycerol and fatty acids. From these raw materials, other lipids can be made. Fats make up cell membranes, hormones and the oils in your skin and hair.

This refers to the number of carbon-hydrogen bonds in lipid molecules. Something that is saturated is going to be almost exclusively carbon-hydrogen bonds. If there are no carbon-hydrogen bonds, then the double carbon-carbon bond will take the place of carbon-hydrogen bonds. Saturation is when the lipids hit the point where the carbon-hydrogen bonds take place.

Oils are unsaturated lipids and you can figure this out because there's the bending effect that keeps everything sort of close together in the molecules, causes more energy and more collisions and so on. The saturated lipids are the ones with the bending effect in their molecules so that there's the carbon-hydrogen atoms that are bonded together, this means that they are going to be solids at room temperature (they don't keep heat as well as unsaturated liquid lipids).

Fats provide twice as many Calories per gram as carbohydrates. Lipids and fats are excellent ways to store energy for future use. When eating excess food, the body stores extra energy by producing fat. It is deposited in a layer just under the skin. The body is able to produce the fat via glycerol molecules that are produced by the liver. Diets of most Americans include too high of a proportion of fats.

Vitamins are complex organic molecules that are needed by the body in very small amounts (coenzymes). With the single exception of Vitamin D, vitamins are not made by the body and must be obtained from food. What Vitamin D does is it goes to the epithelial layers of the skin and provides for the method by which melanin can absorb photons and convert some molecule such that more melanin are produced, or something like this—see the recent biology answers that were written concerning the 15 questions on the role of the endocrine system, integumentary system, and immune system.

Vitamin D can be made in the skin under direct sunlight. Vitamin D involves the conversion of cholesterol to Vitamin D by enzymes and sunlight.

Most vitamins can be obtained naturally by eating a balanced diet that includes fresh fruits, vegetables, and meats. You should try to eat fresh foods, but then try freezed foods, and then canned food should be eaten as a last resort. The frozen foods are “flash freezed” whereas canned foods go through numerous bacterial cleaning processes that includes heating the canned foods, which destroys some of the nutrients in the canned foods in the first place.

When the body does not receive a sufficient supply of vitamins, it can develop vitamin deficiency diseases. As an example, scurvy, where your teeth fall out because the holes in your gums enlarge. It's the lack of Vitamin C in their diets.

Inorganic substances required for the normal functioning of the body are called minerals. As an example, calcium is a major component of bones and teeth. Most of these minerals are going to be metals and compounds not including oxygen, hydrogen and carbon. Many minerals are going to be anions or cations. Iron is essential for transporting oxygen in blood. Iron is found in hemoglobin. Iron deficiency causes hemoglobin problems and erythrocytes problem.

There's also the sodium-potassium ion pump as well, which requires minerals to function. So your body requires minerals in order to keep the nervous system, including the brain, functioning. The sodium-potassium ion pump moves electrical charge.

Nerves and muscles need potassium, sodium, calcium and magnesium to function properly. The calcium is needed in order to make the contractions work, as we discussed in the physiology of muscle contractions and the sliding filament theory of sarcomere contraction.

The body loses minerals through sweating, urine, and feces—maybe also saliva. The body cannot store most minerals.

You would die from a lack of water before you die from a lack of food. Water accounts for at least half of your total body mass. Blood plasma is 90% water. Water is a solvent in which foods and certain enzymes are dissolved in digestion. Water is the universal solvent. Water helps to regulate body temperature, because water can absorb quite a bit of heat in a small volume.

Water dissolves the waste materials that are eliminated in the urine. Sweat glands also remove water from our tissues to cool the body, because water can carry heat and this means that once water absorbs the heat, it can be removed from the system along with the heat.

Each time we take a breath we lose water, when we breathe out at least. Every day, your body loses between 3 and 5 liters of water through sweat, urine and exhaled air. One liter is roughly one quart, so you're talking about roughly one gallon of water per day more or less. You sweat much more than you think you do, especially your feet and your hands, you have a lot of sweat glands on the bottom of your feet and in the palms of your hands.

Dehydration can occur and cause death if you lose as much as 12% of your body water.