Alterations to Metabolism and Energy Production

Question 1

Carbohydrate, Fat & Protein Metabolism

Answer 1

Protein –> amino acids - Proteases

Carbohydrates –> Glucose - Amylase

Fats –> Fatty acids & Glycerol - Lipase

Question 2

Three main pathways of metabolism the human body

Answer 2

Catabolism (breaking down), Anabolism (Building up) and Waste Disposal (removal)

Question 3

Chemical Equation for energy production

Answer 3

ATP + H2O —–> ADP + Pi + free energy

Question 4

Source of energy that fuels cellular functions

Answer 4

ATP

Question 5

Which vitamins are essential for mitochondrial function and aerobic
respiration?

Answer 5

Vitamin B1, B2, B3. B6, B12, folic acid

Question 6

Would the availability of oxygen impact on the amount of energy
that is produced by the cell?

Answer 6

Without oxgyen, the process will only produce 2 ATP molecules, whilst with oxygen, it produces 38 ATP molecules

Oxygen improves the efficiency of ATP production

Electron transport chain - needs the oxygen thus anaerobic respiration only produces 2 ATP molecules

Question 7

Explain why hypoxia leads to multiple system failure

Answer 7

Oxygen is needed for the electron transport chain (oxidative phosphorylation)

• No O2 means no regeneration of NAD and FAD which leads to no ATP output which causes cellular failure and organ failure

Question 8

What is glycogen synthesis and where does it take place?

Answer 8

Where glucose molecules are added to chains of glycogen for storage, it takes place in many tissues, but it important in the liver and muscle

Question 9

What is Gluconeogenesis?

Answer 9

Process by which glucose is made from the biosynthesis of simpler non-carbohydrate precursors such as pyruvate

examples of non-carbohydrate substrates include:

• lactic acid
• amino acids
• glycerol

Question 10

Jennifer is currently on the Atkins diet and is not consuming any
carbohydrates. Would she still be able to make energy?

Answer 10

Body starts to burn fat, causing build up in ketones in the blood, leading to ketosis

Question 11

What happens when N2 is kept in the body

Answer 11

• Excess nitrogen is excreted from the body.
  Nitrogenous wastes tend to form toxic ammonia, which raises the pH of body fluids. The formation of ammonia itself requires energy in the form of ATP and large quantities of water to dilute it out of a biological system.

These wastes are converted to less harmful urea by the liver
It can lead to cerebral oedema, confusion, delirium due to its effects on brain tissue

Question 12

What factors influence enzyme function?

Answer 12

pH
- enzymes function within a narrow pH, changes lead to denaturing

Temperature
- Work best at an optimal temperature, changes lead to denaturing - this is due to the breakdown of intra-intermolecular forces due to increased kinetic energy

Initial concentration of substrate and enzyme

Question 13

Why would a mutation in the DNA of an enzyme result in it becoming ineffective?

Answer 13

when gene mutation occurs, an amino acid may change in the sequence

• Protein folding is highly dependent on amino acid sequence and composition, alterations will change final structure and reaction sites thus enzyme may lose its functionality

Question 14

Two common IEM are phenylketonuria and cystinuria. Describe

these disorders including their incidence rates

Answer 14

Phenylketonuria (PKU) is a rare inherited disorder that causes an amino acid called phenylalanine to build up in the body. PKU is caused by a defect in the gene that helps create the enzyme needed to break down phenylalanine, can cause intellectual disabilities

Cystinuria is an inherited disease that causes stones made of the amino acid cystine to form in the kidneys, bladder, and ureters

Cystinuria is caused by too much cystine in the urine. Normally, most cystine dissolves and returns to the bloodstream after entering the kidneys. People with cystinuria have a genetic defect that interferes with this process. As a result, cystine builds up in the urine and forms crystals or stones

Question 15

Name disease that can cause malabsorptionand maldigestion

Answer 15

Crohn’s disease, Anorexia nervosa, Coeliac disease

• if patient is not absorbing right nutrients, the patient may not be able to produce all of the substrates and products required for metabolism

Question 16

What nursing methods can maintain nutrient levels in a patient who is poorly absorbing nutrients?

Answer 16

Enteral hyperalimentation
- administration of elemental nutrients via a catheter placed within the intestinal tract

Total parenteral nutrition
- feeding a person intravenously, bypassing the usual process of eating and digestion

Nasogastric tubes

Question 17

What are the common diseases in Australia?

Answer 17

Colorectal - 10.7%
Pancreatic - 5.2%
Oesophageal - 3.0%
Gastric - 2.8%
Hepatic - 2.4%

Question 18

Pathophysiology of Colorectal Cancer

Answer 18

Related to colorectal polyps- which is why they are removed in colonoscopy

• Carinoma starts in the glands of the mucosal lining
• genetics and a diet high in fat, low in fibre and low in calcium may promote colorectal cancer development
• bleeding may be evident, pain may be present
• faeces may decrease in size or an obsruction may develop

Question 19

What is irritable bowel syndrome?

Answer 19

An intestinal disorder causing pain in the stomach, wind, diarrhoea and constipation.

Structural changes of the bowel does not occur rather the afflicted person experiences abdominal pain and discomfort and altered bowel habits

• Difficult to define as structural changes don’t occur

Question 20

Pathophysiology of Crohn’s disease

Answer 20

Inflammatory disorder that affects the small and large intestine

• Neutrophils and macrophages promote inflammatory reaction
• Genetic predisposition and alterations in normal bowel flora is suspected

Question 21

Pathophysiology of Diverticular Disease

Answer 21

Condition that causes small bulges (diverticula) or sacs to form in the wall of the large intestine (colon)

Diverticula are sac like out pouchings or hernitations that occur in the mucousae and protrude through the muscle layers of the large intestine

• Regular consumption of a low fibre diet reduces faecal bulk - thus reducing the diameter of the colon - diverticula can rupture under increased pressure

Question 22

Pathophysiology of Appendicits

Answer 22

Inflammation of the Vernifor Appendix

• Exact mechanism is controversial
• obstruction of the lumen with faeces, tumours etc.
• consequent bacterial infection leading to oedema, gangrene and perforation

Question 23

Describe Peptic Ulcer Disease

Answer 23

Peptic ulcer is a break (ulcerations) in the wall of the mucosal lining of the stomach or duodenum

• Can cause significant bleeding

Risk factors include

• smoking
• increased age
• habitual use of NSAIDS
• Alcohol
• Physiological Stress

Question 24

What nutritional disorders occur as the result of alteration in digestive physiology?

Answer 24

Lactose intolerance
- Due to deficiency in the enzyme lactase which breaks down lactose into its smaller components glucose and galactose

Coeliac disease
- loss of the mature intestinal villi caused by a hypersensitively to gluten. This results in malabsorption of nutrients

Question 25

Why does lactose intolerance cause diarrhoea and abdominal pain?

Answer 25

Bacterial fermentation of undigested lactose leads to increased gas production which stretchs the intestines causing pain

Undigested lactose changes the osmotic gradient in the intestine causing fluid to be drawn into the intestine, thus causing diarrhoea

Question 26

Discuss Malnutrition & Starvation

Answer 26

Malnutrition

• Lack of nourishment from either inadequate
• KJ, protein and vitamins or minerals

May result from an improper diet, alteration in digestion or absorption

Starvation

• extreme malnutrition days to weeks. body uses glucose stores then starts breaking down fat then protein for energy. Extreme tissue wasting occurs
• Cachexia (extreme wasting) can occur in cancer patients where the cancer is using up nutrients at a rapid rate