OPTION D.1-Human Nutrition Flashcards
Why is Threonine conditionally essential?
Can be synthesised by the body if phenylalanine is present
Why is Arganine essential?
Can normally sufficiently be made by healthy individuals
→ BUT synthesis pathway isn’t active in prematurely born infants = MUST get from diet!
If there’s a shortage of one essential aa what happens to the bodu?
Can’t make enough proteins = can cause malnutrition
Protein deficiency malnutrition
+ Causes lack of blood plasma proteins
→ fluid retained in the tissues
+ Causes swelling (edema) most obvious in abdomen
+ Child =dev. both mentally and physically retarded
+ Adult = wasting = serious weight loss
Why is iodine needed?
+ Thyroid gland to synthesis hormone = thyroxin
→ Stimulates metabolic rates
→ ensures energy = released in the body
IDD (Iodine Deficiency Disease) consequences
+ Women = pregnant = IDD = baby may be born w/ permanent brain damage
+ Child = IDD = after birth
→ mental dev. and intelligence impaired
Starvation (Malnutrition)
+ linked to poverty
+ consequence of diet lacking in adequate protein and carbs
→ unbalanced and fail to provide essential nutrients
Obesity
+ diet contains excess fats and refined carbs
+ observed in developing countries
= unhealthy diet
What is the Hypothalamus responsible for?
Making us feel satisfied when we hv. eaten enough food (satiated)
When the appetite control centre receives what hormones and what proportion of them do they then tell body to reduce appetite?
→ Helps body avoid health problems
1) Small intestine secretes hormone PYY3-36 when it contains food
2) Pancreas secretes insulin when blood glucose conc. is too high
3) Adipose tissues secrete hormone = leptin when amt of fats stored increase
Diabetes Mellitus what is it and symptoms (3)
Condition where sugar is present in the urine! When it is NOT suppose to be present
+ Elevated levels of blood glucose
+ Glucose in urine
+ dehydration and thirst resulting from excretion of large vol. of urine
Type I Diabetes
+ Auto-immune destruction of insulin-secreting β-cells in the PANCREAS
+ Early onset
Type II Diabetes
+ Decreased responsiveness of body cells to insulin due to “burn-out”
+ Late onset
Risk Factors of Type II Diabetes (3)
→ increase blood conc. of fatty acids
+ diets rich in fats and low in fibre
+ Obesity due to overweight and lack of exercise
+ Genetic factors which affect FAT metabolism
What are the 2 consequences of Obesity?
1) Hypertension
2) Type II Diabetes
Other problems stemming from Diabetes (3)
→ related to cardiovascular system
1) Atherosclerosis = narrowing of arteries by fat deposits
2) Hypertension (high bp)
3) CHD = narrowing of coronary arteries
What can weight gain cause that lead to hypertension? (5)
+ Increase the release of several hormones
+ Cause changes in body physiology and anatomy
+ Lead to higher cardiac output = increase bp
+ Abdominal obesity = increase vascular resistance = increase bp
+ Associated w/ arteries becoming stiffer and narrower = increase bp
What can hypertension also be caused by? (other than weight gain)
HIGH salt intake
→ salt has osmotic effect
What is the effect of starvation?
+ Leads to breakdown of body tissue
+ When there is no dietary intake of energy source
→ body will resort to glycogen stores
→ break down own muscles and tissues to use resulting aa’s as energy (sent to liver to convert to glucose)
LOSS OF MUSCLE MASS
Anorexia Nervosa
Psychiatric illness → complex causes
+ voluntary starvation
+ loss of body mass
What happens when a person has Anorexia Nervosa?
+ amt of carbs and fats consumed = too small to satisfy the body’s energy requirements → proteins and other chemicals in body broken down instead
What are the consequences of Anorexia Nervosa? (4)
+ Wasting of muscle
+ Skin dries and bruises easily
+ Females= lead to infertility
+ Hair becomes thin and can drop out
Why does having Anorexia Nervosa lead to low bp and poor circulations/ slower heart rate/ lower heart output?
+ Heart muscle can also deteriorate
+ lack of dietary intake can alter electrolyte balance
→ leads to skeletal and cardiac muscle not contracting normally
Phenlyketonuria (PKU) what is it?
Genetic disease caused by mutation of a gene coding for enzyme that converts
Phenylalanine → Tyrosine
+ Allele needed for the conversion is dominant
+ symptoms only occur in individuals that have 2 recessive alleles
Phenlyketonuria (PKU) what happens?
Mutations produce alleles of gene that code for enzymes = unable to catalyse the conversion!
+ Phenylalanine build up in body
+ shortage of Tyrosine = essential aa!
