Enzymes: What Are They?
The activation energy needed to initiate an exergonic or endergonic reaction can be heat energy or chemical energy. Chemical reactions that require activation energy can also be sparked by biological catalysts called enzymes. Enzymes are proteins that speed up chemical reactions that require activation energy can also be sparked by biological catalysts called enzymes. Enzymes are proteins that speed up chemical reactions while themselves remaining unchanged. Essentially, they lower the required amount of activation energy needed for chemical reaction.
Each enzyme catalysts only one reaction; there are thousands of different enzymes in a cell catalyzing thousands of different chemical reactions. The substance acted on by an enzyme molecule is called the substrate. The products of an enzyme-catalyzed reaction are called end products. A key portion of the enzyme, called the active site, interacts with the substrate to produce the end product. With some exceptions enzyme names end in "-ase." For example, catalase is the enzyme that breaks down hydrogen peroxide to water and hydrogen. Other enzymes are amylase, hydrolase, peptidase, and kinase. Enzyme reactions usually occur in milliseconds. The rate of an enzyme-catalyzed reaction depends on a number of factors, among which are the concentration of the substrate and the acidity and temperature of the environment. At higher temperatures, enzyme reactions occur more rapidly, but excessive amounts of heat may cause the protein to change its structure and the enzyme to denature (lose its physical structure).
Enzymes work together in metabolic pathways. A metabolic pathway is a sequence of chemical reactions occurring in a cell. Certain metabolic pathways involve catabolism, which is the breakdown or digestion of large, complex molecules. Other Metabolic pathways involve anabolism, which is synthesis of large molecules. The pathways of metabolism will be discussed this week.
Does Nutrition Affect Breast Milk?
Human breast milk is unlike any type of milk produced by any animal or seen in any formula on the market. The unique composition of breast milk makes it an ideal first food for your growing baby. The physical structure of human breast milk is unlike any other type of milk. It contains different types and concentrations of micronutrients, like vitamins and minerals. There are different enzymes, hormones, growth factors, host resistance factors and other immune supporting elements that make human breast milk the best choice for nutrition and overall health. If you are studying to become a nutritionist or a lactation consultant this is something that a new mother may ask.
The composition of breast milk can be affected by maternal nutrition. There are certain generalizations that can be made concerning the relationship between nutrition and composition.
-The macronutrient level found in human breast milk is not affected if less than the daily recommended dietary allowance is consumed. However, the number and proportions of different dietary fatty acids will vary according to the mother’s dietary intake.
-Major minerals like calcium, magnesium, phosphorus, sodium and potassium are not affected by diet. Regardless of dietary intake, the milk supply will have the necessary amount of these minerals. Although this is good for the infant, the source of these minerals if not obtained from dietary intake will come from the mother’s reserves.
The maternal intake of selenium and iodine will directly relate to the amounts found in breast milk.
-The amount of vitamins available in breast milk is determined by the amount of vitamins the mother consumes daily or the amount she has available in her vitamin stores. If a mother does not consume enough vitamins, her milk is likely to show a low vitamin content.
-Folate and calcium are usually adequately found in maternal milk at the expense of the mother’s maternal stores. If she does not supplement these minerals, she may end up with a deficiency in these minerals.
To ensure the composition of your breast milk is sufficient for your baby’s needs and not likely to cause your body to use any of your vitamin or mineral reserves, be sure to consume nutritious food, take a vitamin supplement or continue with your prenatal vitamins. Discuss supplement options with your pediatrician
Tips For Grilling Foods
Food has been grilled for thousands of years. This method of cooking is an effective way of preserving flavor and nutrients while keeping food free from harmful bacteria, however, there are a few simple rules that should be followed when grilling foods especially if you are interested in Culinary Arts and Nutrition.
Grilling- whether by gas flame, electric element, charcoal or wood - requires the use of temperatures that are four to six times hotter than a standard oven. The high heat of grilling can quickly turn unpalatable if the food becomes charred. Grilling is best reserved for foods that are considered “quick-cooking” foods, like fish and thinner cuts of meat and poultry.
At grilling temperatures the surface of meat burns away and acrid fumes are released. The smoke that is generated when fat drips into the fire contains carcinogens. All grilling should be done in a well ventilated area. The best way to minimize exposure to fumes is to partly bake or parboil the food first, before grilling.
Eating broiled or fried meats have been found to expose the body to up to 50 times more DNA-damaging chemicals than eating meats that have been boiled or baked. Hydrocarbons have been found to form in broiled meat and carcinogenic nitorsomines have also been found to form during cooking and in the digestive tract when foods that contain nitrite are cooked and eaten.
To protect yourself from the damaging effects of grilled foods, consider consuming vitamins C and E. These vitamins have been found to block the chemical reaction that creates nitrosamines in the digestive tract. Eating foods like bran can also help to keep nitrosamine from forming by binding with nitrite. Eating ample amounts of leafy greens and whole grain salads with grilled meat can also help to dilute carcinogens and speed their elimination from the body.
Food Sensitivities
Almost everyone has eaten something that causes stomach upset. This can also occur with your baby through the foods you eat. In the same way that certain foods can cause you stomach upset, certain foods that you eat can cause your baby stomach upset as those foods are transferred through breast milk. There are several responses your baby may have to foods that cause upset. Your baby may respond by crying, fussing, nursing more frequently, and generally being inconsolable. Many parents can easily confuse stomach upset with colic but there is a difference between the two. Colic generally occurs on a daily basis during the first three months after the baby is born. The fussing that occurs from food sensitivities takes place only after the nursing mother eats a particular food. The response to the food usually clears up in less than twenty-four hours.
There are certain foods that are known to cause more gas than most foods. “Gassy” foods, such as cabbage, onions, garlic, broccoli, and turnips have been known to cause discomfort to many breastfed infants. Your baby may react to other foods that are not listed. Usually food sensitivities resolve in less than twenty-four hours and will not reappear until the offending food is eaten again.
Some babies have a true allergy instead of food sensitivity. Food allergies are usually rare in babies. A baby that suffers from a food allergy will usually experience general fussiness that is similar to colicy behavior. However, a food allergy may cause strong gastrointestinal discomfort. If your baby experiences this type of discomfort, he may draw up his legs in pain. If you notice that your baby seems to be experiencing pain after a feeding consult with your midwife or pediatrician before you eliminate any suspect foods from your diet. Avoid eating the suspect food for two weeks. If your baby’s pattern of colic continues than it is likely that your baby has true colic rather than a food allergy. If the discomfort disappears during this period, a food allergy should be seriously considered.
Lactation Consultants and Nutrition
Human breast milk is often a baby’s first food. The components of breast milk are designed by nature to provide a baby with all of the important nutrients needed for sustaining life and promoting growth. Human breast milk contains important ratios of carbohydrates, proteins, and fats. When we think of nutrition, we often think of dieting, and food.....but what about babies? We decided to ask a lactation consultant for some insights. The most variable compound in human breast milk is fat, which provides up to 50% of a baby’s calories.
Breast milk contains a relatively stable ratio of saturated to unsaturated fat. Approximately 42% of fat is saturated and 57% is unsaturated. Some studies have found that women who smoke have decreased levels of essential fatty acids in their milk. Essential fatty acids are important for brain development and may influence intelligence.
Lipases are enzymes that are released simultaneously in saliva to break down long-chain fatty acids. The release of these enzymes helps with digestion. Free fatty acids are beneficial because they kill bacteria and parasites. Many types of viruses are also inactivated by free fatty acids.
The amount of fat found in breast milk is not based entirely on the mother’s diet. There are many variations in fat levels of breast milk. The profile of fatty acid chain-length does vary depending on the mother’s diet. The amount of fat available increases within each feed and as the breast “empties.” The amount of fat in breast milk has been found to increase greatly in the second year of lactation.
Even cholesterol is necessary in breast milk. This often disdained component of fat is essential for all membranes. Cholesterol plays an important role in the development of brain tissue. It is necessary for myelin sheath which is necessary for nerve conduction in the brain. Research has found that breastfed babies have higher levels of cholesterol than formula-fed infants.
Fatty acids play an important role in cognitive development. Without fatty acids vision and nerve myelinization would suffer. Essential fatty acids like docosahexaenoic acid (DHA) and arachidonic acid (AA) are especially important for brain maturation.
Hernias and Heartburn for Athletes
Strength training athletes as well as many other athletes that use strength training exercises should always consider proper form when lifting heavy objects like weights. Using incorrect form or rushing through a movement can cause an exceptional amount of strain. In some cases, a hernia can result.
A hernia occurs when an organ protrudes through the muscular wall that surrounds it. The name of the hernia is designated by the anatomical region that the peritoneal protrusion takes place, such as inguinal, diaphragmatic, and umbilical.
A hiatel hernia is a structural abnormality that is often caused by an abnormal relaxation or weakening of the gastroesophageal sphincter. This abnormality causes the superior part of the stomach to protrude above the diaphragm. With the stomach above the diaphragm, the sphincter is no longer reinforced and gastric juices are able to enter the esophagus, resulting in heart burn.
Heart burn is the first symptom of gastroesophageal reflux disease (GERD). There are several symptoms that are associated with heart burn such as burning, radiating substernal pain that occurs primarily when the acidic gastric juices from the stomach enter into the esophagus. Many of the symptoms of heart burn can be mistaken for symptoms of a heart attack for first-time sufferes. Many heart burn sufferers experience pain after eating or drinking to excess. People who are obese or pregnant often suffer from heart burn due to abdominal contents being forced superiorly. Even athletes, like runners, can experience heart burn if their stomach contents are splashed upward from running.
How To Prevent Constipation
Most people have had a bought of constipation at some time in their lives. Constipation is characterized by very few bowel movements, which, when they do occur, tend to be hard and sometimes painful to pass. There are many possible causes of constipation. Generally, this disorder can often be remedied by improving your diet and exercise. Also stress level may be a contributing factor. While studying to get my allied health degree, I experienced irregularity due to all three of the above causes.
Most cases of constipation are caused by a lack of fiber and liquids in the diet. Fiber rich foods help to keep the bowels clear. Fruits and vegetables are excellent sources of fiber and should be eaten frequently throughout the day. Water is the very best type of liquid a person can drink. Although consuming many other types of liquids can help to prevent or relieve constipation, water remains the very best choice because it does not have added sugar or caffeine. A lack of exercise can also slow bowel movements and cause constipation. Regular exercise helps to stimulate abdominal contractions of the bowel muscles causing the feces to move more easily through the bowel. Should you have the urge to use the bathroom and ignore that urge, you may end up with hard, impacted stools. It is always best to heed the urge to use the bathroom. If you are constipated, it is best to avoid depending on laxatives to relieve your symptoms. Laxatives and other types of drugs can impair normal bowel function.
Some common signs of constipations include infrequent, difficult and possibly painful bowel movements; straining during bowel movements; a feeling of fullness after a bowel movement; hard, dry stools; and abdominal swelling. If you experience any of these symptoms, consider altering your diet to include more fiber rich foods and liquids. Also, exercise regularly- preferably daily. If this does not relieve your symptoms after two weeks, make an appointment with your doctor. It is also important to call your doctor right away if you experience fever or severe abdominal pain, bloating, cramping or blood in your stool. If you experience constipation after starting a new medication, you may need to have your prescription adjusted.
Malnourishment
Would you believe it if I said that most people today suffer from some degree of malnourishment? I know it seems a bit far fetched, considering all of the food that is available in the United States. Oh, and don’t forget that we are considered the most obese nation. So how is it possible that we could actually be considered malnourished? The answer is simple. Our food doesn’t contain all of the nutrients it used to.
Unfortunately our soils are depleted of vital minerals. This depletion directly affects our produce. Without essential minerals, like zinc, that are already deficient in the soil of many states, fruits and vegetable no longer contain the same proportion of minerals. Many genetically modified fruits and vegetables are created to be able to grow in mineral deficient soils. Although genetically modified produce may look nutritious, they often lack important dietary minerals.
Many people do not eat fresh produce. Instead canned foods are eaten which are usually stored for long periods or cooked improperly causing all of the remaining nutrients to be cooked out. This causes even fewer minerals to be available to the body. Many people are unaware of how to prevent the loss of water-soluble vitamins from foods or how to prevent destroying heat-liable vitamins during cooking.
Refined foods are becoming more prevalent in western diets. The added convenience, often reduced costs, and satisfying flavors are appealing but lack any real nutritional value. With all of these compounded weaknesses in our food production and dietary choices it is very easy to see how we can be considered malnourished.
The best way to ensure that you are getting the most nutrition out of your food is to choose organic foods. Unfortunately, organic is often much more expensive. The added cost aside, most organic foods are grown under stricter guidelines. It is best to choose foods that come from reputable organic farmers.
Exercise and the Menstrual Cycle
Exercise is not the only reason why many female athletes have problems with their menstrual cycles. A combination of exercise and caloric intake can cause menstrual abnormalities. A majority of menstrual problems are associated with women who are involved in sports that encourage lower body weight, such as gymnastics and cross country running. Other types of sports that focus on weight for classifications, such as weightlifting and wrestling can also promote menstrual problems. When high levels of exercise are combined with low calorie intake, the risk of increased menstrual problems increases significantly.
Athletes tend to have higher incidences of secondary amenorrhea compared to women who have less active lifestyles. This is primarily because of the differences associated with an athletic lifestyle that is more physical, nutritionally restricted and emotionally stressful.
Proper nutrition is essential for athletes. An athlete usually expends a significant number of calories while training and throughout the day. The body requires nutrition to provide the calories necessary to meet the demands placed on the body. Without adequate nutrition the body is unable repair and remodel muscle tissue. Often many women do not consume enough protein to meet the demand for amino acids need for protein synthesis after a rigorous strength training workout. Reduced calcium intake can also affect the body and ultimately the menstrual cycle.
To prevent menstrual abnormalities female athletes should ensure that they are eating enough calories each day, choose foods that offer the protein and calcium that is necessary for muscular repair, development and other body functions.
Fat Soluable Vitamins
Fat-soluble vitamins, A, D, E and K, are absorbed by the intestinal tract in the same way that fats are metabolized by the body. Because these vitamins are processed in the same manner any condition that may interfere with the absorption of fats will also interfere with the absorption of fat-soluble vitamins. Celiac disease is an example of a condition that can cause the malabsorption of the fat soluble vitamins D and K as well as other water-soluble vitamins and minerals.
The liver, fatty tissues and muscle are the main storage areas for fat-soluble vitamins which are eventually excreted slowly in urine. Some fat-soluble vitamins, like vitamin A, can be stored in the body for up to two years.
Vitamin A is used by the body to maintain epithelial tissue, eyes, hair and bone growth. If taken in excess, vitamin A can have a toxic effect. Pregnant women who take more than 6000 international units (IU) of vitamin A have an increased chance of birth defects. Because this vitamin can be stored for two years in the liver, the chances of inadvertent toxicity are greater than other fat-soluble vitamins.
Vitamin D requires the help of bile salts in order to be absorbed in the small intestine. Without vitamin D, calcium can not be metabolized. We can obtain vitamin D in two forms. D3 is the natural form of vitamin D that is produced in the skin by ultraviolet sunlight. The synthetic form of vitamin D is D2.
Vitamin E helps to protect the heart and arteries as well as other cellular components of the body from oxidization. It also helps to prevent the rupturing of red blood cells. It can be found stored in all tissues of the body, especially the liver, muscles and fatty tissues. Most excess vitamin E is excreted in the bile. Whatever is not excreted in the bile is excreted in urine.
Vitamin K is synthesized in the body by intestinal flora. It is necessary for the synthesis of prothrombin and certain clotting factors. A deficiency of vitamin K can allow for hemorrhaging. Vitamin K is stored in the liver and other tissues.
