Custom «Health» Essay Paper Sample

All physical activities performed by people are either aerobic, anaerobic or a combination of both. Aerobic activities require delivery of oxygen to the muscles and tissues together with other nutrients. They involve large muscle groups and usually over long sustained periods of time. Running for forty five minutes would be an aerobic activity which effectively increases aerobic fitness with constant practice. Any physical activity which raises the heart rate and maintains it for at least twenty minutes in the target zone is considered aerobic.

Anaerobic activities do not require energy and they take place with quick and short bursts of body energy. Examples include sprinting, weight lifting, tennis and racquetball. These exercises are usually short in duration. Lactic acid is produced as a by product of anaerobic physical exercises and it is the reason behind the burning one feels in the muscles during and after these activities. The two physical activities, running for forty five minutes and weightlifting for thirty minutes, would be a combination of both aerobic and anaerobic activities. This improves both aerobic and anaerobic fitness, which is necessary for optimal body health (Hagen, 2010).

The meal consisting of baked chicken (three oz) marinated in one tsp olive oil and spices, one cup of rice and one-half cup beans together with the two cups salad with two tablespoons ranch dressing and one cup of skim milk, consists of food sources of carbohydrates, proteins and fats.

The proteins are fundamental and basic components of all living cells. These include many of the substances such as hormones, anti bodies and the enzymes, all these are essential for the living organisms' proper functioning. Proteins are a group consisting of complex macromolecules containing carbon, hydrogen, oxygen and nitrogen usually together with sulfur and they are composed of one or more chains of amino acid. Protein foods in the meal plan are chicken, the beans, and the skim milk. The chicken is a protein source with approximately 48g of protein / 6 ounce serving. The amount of fat in the chicken will vary depending on whether it is skinless or not (ehow). The beans are legumes which form important sources of essential proteins. They are high in protein with approximately 24 g of protein per 100 g of dry beans. Carbohydrates are relatively higher with 60 g per 100 g and the fat content for the same amount is 1g. These values are different in green beans.

The total fat content in food includes the saturated, monounsaturated and polyunsaturated fats. The skim milk is fat free with traces amounts of fats, approximately 0.4 g in one cup of skim milk. The protein content in the one cup is about 8 g with the carbohydrate constituting 12 g (arrya).

The Ranch dressing used in flavoring the salad is a popular dipping sauce with a high fat content. One typical two table spoon of ranch dressing contains about 15 g of fat and 145 kcal or 608 kJ. About 95% of the calories come from the fat.

The one half-full cup rice forms the major source of carbohydrates in the meal. The other foods in the meal also do have varied amounts of carbohydrates, albeit mainly at the trace levels. cooked rice with a weight of about 100 g will have 28.5 g of carbohydrates, 2.4 g of proteins and a total fat content of about 1.1 g (atu).The vegetable salad approximately contains 3 g of carbohydrates per 85 g with the protein being 1.0 g ().

Digestion refers to the process of breaking down the food, mechanically and chemically, into the smaller components for easy absorption. Food is first mechanically broken down in the mouth by chewing as it mixes with the enzymes contained in saliva before swallowing. The digestion process for the carbohydrates, fats and proteins, involve different enzymes and chemical processes.

The carbohydrates' digestion begins in the mouth. The enzyme amylase in saliva breaks down the more complex carbohydrates into simpler states. Its activity continues within the stomach but this slows down with the release of digestive acids. The pancreas secretes another version of the amylase in the duodenum, which further breaks the carbohydrates to - lactose, maltose and sucrose, which are simple sugars. The enzymes lactase, maltase and sucrase further act on the food as it moves into the intestines. These break the lactose, maltose and sucrose into more absorbable smaller bits. These are eventually converted to glucose and then absorbed into the blood stream through the walls of the intestines (Collins,).

Digestion of the proteins begins in the stomach, unlike in the case of carbohydrates. The gastric juice secreted in the stomach contains hydrochloric acid, mucous and the digestive enzymes. The hydrochloric acid softens the proteins before the enzyme pepsin further breaks these into proteose in the stomach. These are then acted on by the enzymes trypsin and erepsin in the intestines and broken down to peptones, which are later broken down to smaller portions called amino acids. The amino acids are then absorbed into the blood stream through the intestinal walls (Kumari, 2010).

The fats take longer to digest than proteins and carbohydrates as they do not dissolve in water. The digestion of fats begins in the duodenum, with the lipid molecules forming a semi-solid mass as they do not dissolve in water. The digestive enzyme lipase, secreted by the pancreas, breaks the lipid molecules in the duodenum into fatty acid and glycerol molecules (Collins, 2007). The bile emulsifies the fats, allowing lipase to gain access to the smaller fat molecules. Lipase and the other digestive juices further break down the fat molecules in fatty acids and types of glycerol. These are then easily absorbed by the villi in the intestinal walls into the blood stream (Collins, 2007).

In working out energy is required and this is provided in the form of adenosine triphosphate ATP. The body stores this energy in small quantities which can be used up in a few seconds, requiring the body to replace this on an ongoing basis. The main pathway used when first starting to work out is glycolysis. Glycolysis is an ATP generating metabolic process that involves the breaking down of glucose to pyruvic acid, in a series of reactions involving enzymes. The carbohydrates consumed provide the body with glucose, which is stored as glycogen in the body muscles and liver for later use in energy formation. The glucose is the macronutrient in this pathway with pyruvic acid as the end product.

Glycolysis converts a molecule of glucose into two molecules of pyruvic acid as see in the biochemical equation below.

(C6H12O6 + 2NAD+ -> 2C3H4O3 + 2NADH + 2H+)

The free energy that is stored in the 2 molecules of pyruvic acid is usually less than the energy stored in the initial glucose molecule. Beta-oxidation is the metabolic process in which fatty acids are broken down to Acetyl-CoA, in the mitochondria part of the cell. The fatty acids, which are in the form of Acyl-CoA molecules, form the macronutrients in this pathway with the acetyl-CoA as the end products. This process results in formation of ATP for energy to be used during the physical work out.

Gluconeogenesis refers to the synthesis of glucose whereby the molecules used are not derived from carbohydrates but from other molecules such as amino acids, glycerol and fatty acids. This primarily occurs mainly in the liver and kidneys, whenever carbohydrate supply is insufficient to meet the metabolic demands of the body. This process takes place such settings as during fasting, starvation, and periods of intense exercise and with intake of diets low in carbohydrates.

Glucose is formed as the end product of this process which is then broken further through glycolysis. Cl is important during work out as it helps in supplying glucose from non-carbohydrate molecules, with glucose being further broken down for energy required during the work out.