Lipoproteins In Hepatic Cells

The concept of energy intake and expenditure refers to the amount of calories per day that an individual consumes, and is the chemical energy in foods which can be metabolized to produce energy available to the body. As stated before energy is obtained from the foods we eat and is used to support an individual’s Basal Metabolic Rate, energy is measured in calories or joules as both units are very small they are multiplied by 1,000 and referred to as kilocalories. Different foods provide us with different amounts of energy, and the potential fuel sources available to exercising muscles are fats – 1 gram fat =9.0kcal = 23kJ,

The digestion of lipids occurs mostly in the small intestine, mainly the upper jejunum. Lipases from the pancreas are secreted into the small intestine as a part of pancreatic enzyme and breakdown lipids to fatty acids. Bile salts, created by the liver, enter the duodenum to mix with fatty acids to form micelles. The development of these micelles allows the absorption of fatty acids at intestinal villi. Pancreatic lipase, bile salts and functioning lymphatic channels help break up fat if these are working correctly then steatorrhea

As we eat protein, fat and carbohydrates, as the main energy source, carbohydrates or glucose (simple sugar) break down into complex molecules. We need steady supply of glucose in between meals and at times like doing extensive workouts, there is an elevated demand for

Nutritional factors that can cause fatigue include depletion of glycogen stores, low blood-glucose levels, dehydration, low blood-sodium levels and gastrointestinal upset (Hargreaves, 2001). Eating strategies should be undertaken to avoid or reduce the impact of these problems. (Asker, 2011) states that the effect of high-CHO intake in a diet increases muscle glycogen and in-turn reduces the risk of chronic carbohydrate depletion which can lead to poor performance outcomes in a single session and sub-optimal training adaptations in the long term. Therefore, implementing a CHO loading strategy based on training and sporting requirements will assist in performance and reduce the risk of fatiguing. Fat also provides the main fuel source for long duration, low to moderate intensity exercise, such as marathons. It is also a contributor in helping access stored glycogen during high intensity exercise. Daily refuelling allows competition nutritional strategies to be practised and refined and is a crucial strategy to enhance performance and recovery during training and event

A journal published by Allen, Lännergren, and Westerblad (2002) of the American Physiological Society, claimed that during the process of intracellular acidosis, lactic acid is the main cause of skeletal muscle fatigue. However, studies show that inorganic phosphate also contributed to the decline of contractile function in skeletal muscle. This research further explained that high-intensity exercise surpasses the aerobic capacity and the significant amount of adenosine triphosphate required would then be derived from anaerobic cellular respiration (Westerblad, Allen, & Lännergren, 2002).

Carbohydrates are one of the main fuel sources of energy. Carbohydrates are made of carbon, hydrogen and oxygen molecules. Monosaccharides (glucose and fructose), disaccharides (sucrose) are referred as sugar molecules. Aerobic and anaerobic metabolism work together to provide ATP and energy for exercise (Baker et al, 2010). Skeletal muscles use fat and carbohydrate for energy. Therefore, at high exercise intensities, fat does not synthesis ATP, so fat utilisation has a higher amount of ATP. Therefore, glucose utilisation is necessary for ATP synthesis (Milian, 2013).

State the chemical composition of the sterol that is present in high levels in most people who belong to the high-risk group.

The liver is essential to digestion and subsequent metabolic processes. It is a plays a large part in the processing of carbohydrates and lipids. As carbohydrates are absorbed in the small intestine, they are first brought to the liver via the portal vein. Depending on the needs of the body, the liver will either store excess glucose as glycogen or breakdown glycogen to release glucose into the bloodstream. Lipids are not soluble in water and cannot be efficiently absorbed without bile produced by the liver. Bile emulsifies fats and allows lipase, an essential protease produced by the pancreas, to effectively break down complex lipids for absorption.

Brinkworth & Noakes et al, found that in obese subjects having a low carbohydrate diet would in fact increase the amount of fat being oxidised during submaximal aerobic exercise, suggesting that subjects would have a RER closer to .7 than one. Exercise intensities that are less than 65% VO2 max, will be affected little by the percentage intake of fat and carbohydrates. (Miller & Wolfe, 1999) This would suggest that lower intensities don’t rely completely on food sources, but fuel stores already in the body. Exercise at 65% VO2 max will have approximately 50% of the energy supplied by muscle glycogen and plasma together with intramuscular fatty acids will provide around 40% of the energy. At high intensity exercise of above 80% VO2 max, the major source of energy is

Therefore, it needs to be transported through the blood stream by carriers, in this case, called lipoproteins. There are two main kind of lipoproteins, the low density lipoproteins (LDL) and the high density lipoproteins (HDL). The types of proteins are characterized as good or bad to the organisms. In this case the LDL is considered the bad cholesterol because it forms hard layers, that can obstruct the arteries and can make them less flexible to function properly. That is why HDL is considered to be beneficial one, since it as the scavenger that helps to remove the cholesterol from the arteries back to liver. Hence, the cells from those with FH show a deficiency in the number of functional LDL receptors, which at the same time cause the overproduction of cholesterol and a reduction in the ability to breakdown the protein in LDL (Rosenson et

However, the alimentary canal has a generally hydrophilic medium. This causes the lipid molecules to coalesce into a very big lipid globule. This globule has a very small surface area to volume ratio and hence the hydrolysis of this globule would be extremely inefficient even with the presence of lipase. Therefore bile is secreted to emulsify the globules. Bile is produced by hepatocyte cells and stored in the gall bladder below the liver.

Interval training is charactered by intensity, work duration and rest periods. It involves a short or long durations of high intensity exercise repeated with a specific amount of recovery. The training type improves athlete’s performance along with their cardiorespiratory fitness, VO2 max and improves exercise adaptations (Billat, 2001). Exercise intensities elevate ATP utilisation and restrict metabolic processes, increasing the level of blood lactate. The restriction of metabolic processes causes an increase in muscle fatigue. Therefore restoration of metabolic concentrations during recovery periods from intense exercise is important for optimal exercise performance (Edge, Eynon, McKenna, Goodman & Bishop, 2013).

cholesterol. It passes out of the liver through two ducts, one from each lobe. When a fatty meal is

Alkhatib et al. (2015) state that fat utilization during exercise and at rest differ. They note that after sleeping for the whole night fasting, the required energy is covered by the fatty acids oxidized from the adipose tissue. The lipolysis existing in the adipose tissue depends on the hormones concentration in the body. Once exercise gets initiated, the lipolysis rate and the rate of releasing fatty acids from the adipose tissue get enhanced. During exercise of moderate intensity, lipolysis increases threefold since there is an increase in the stimulation of adrenergic. The flow of blood from the adipose tissue gets doubled, and the re-esterification rate reduces by half. The flow of blood to the skeletal muscles increases so that they can deliver the fatty acids to the

Figure 1. Effect of CdCl2 exposition on hepatic lipids. A) Cd concentration, (in the control groups, were not detected). B) Triglycerides level (TG). C) Phospholipids level (PL). D) Esterified cholesterol level (Chol). The results shown are the average of 10 different experiments ± SEM. (*) Indicates significant difference regarding to control group p ≤ 0.05 by Student “t” test.