Molecules, diet and nutrients Flashcards
What is BMR, what factors increase and decrease BMR
BMR - basal metabolic rate, the energy needed to stay alive at rest 1kcal/kg/bodymass/hr = 24kcal/kg/day Changes due to -age (decreases with age) -gender (men have a higher BMR) -body weight (increases with weight) -temp (increases when cold) -caffeine/stimulate (increases) -pregnancy/lactation -diet/starvation
Women BMR = 655 + (9.6 X weight kg X height cm X 4.7 Xage )
Men BMR = 66 + 13.7 X weight, 5 X height - 6.8 X age
How is energy stored in the body?
1) 15kg triglycerides
2) 300g Glycogen -150g muscle -200g liver
3) 6kg protein
What are the essential nutrients of the body?
essential nutrients cannot be synthesised by the body- fatty acids, amino acids, vitamins, minerals
amino acids - nine that cannot be synthesized -phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine (i.e., F V T W M L I K H)
What are the underweight, healthy, overweight and obese ranges of BMI?
BMI - body mass index, varies from men to women. Weight in kg divided height in cm squared
Underweight
How much carbohydrate is needed a day. Give some examples. How much energy per gram?
200-300g/day. Glucose, lactose, starch, frutose, sucrose.
4kcal/gram
Describe the Krebs cycle
- Acetyle(2C) Co A X 2
- 6C compound X2
- 5C compound (loss 2 X c02 and 2 X 2H - reduces NAD)
- 4C compound X 2 ( Co2, 2H, 2H, 2H - reduces 2NAD and 1FAD)
- Acetyle CoA
What is a peptide hormone?
A peptide hormone is made up of amino acids, some have glycoproteins. They bind to receptors on the cells that they affect and produce a quick chemical reaction. They are hydrophilic so they can travel in the blood stream. They are often made in cells then kept in vesicles until they are needed. Lipid-souble but not water soluble.
Eg, vasopressin, insulin, growth hormone
What is a steroid hormone?
Steroid hormones are made from cholestrol, they cannot dissolve in water or lipids. Therefore they bind to transport proteins to travel in the blood stream. They directly affect the DNA of cells so they have a slow response.
eg. Aldosterone, testosterone (-ol or -one)
What are amino acid-derived hormones?
Aminoacid-derived are small hormones that are water-soluble and insoluble in lipids they often end in ‘ine’
eg,
-epinephrine and norepinephrine (adrenal medulla).
-thyroxine (thryoid gland)
-melatonin (pineal gland).
What is a hormone?
A molecule that acts as a chemical messenger
What is primary hypothyroidism?
Primary hypothyroidism means that there is a problem with the thyroid gland. (it is under active)
Because it is underactive less thyroxine is produced, (this is an example of negative feedback), because the anterior pituitary gland detects the low levels o thyroxine it produces an increased amount of Thyroid stimulating hormone (TSH)
Primary hypothyroidism = low thyroxine, high TSH
What is primary hyperthyroidism?
Primary hyperthyroidism means that there is a problem with the thyroid gland. (it is over active)
Because it is overactive more thyroxine is produced, (-ve feedback) because of this the anterior pituitary gland produces less Thyroid stimulating hormone (TSH).
Primary hyperthyroidism = high thyroxine, low TSH
What is secondary hypothyroidism?
Secondary hypothyroidism means that there is a problem with the pituitary gland (it is underactive)
This means it doesnt produce enough thyroid stimulating hormone (TSH), so the Thyroid gland doesn’t produce enough thyroxine.
Secondary hypothyroidism = low TSH, low thyroxine
What is secondary hyperthyroidism?
Secondary hyperthyroidism means that there is a problem with the pituitary gland (it is overactive)
This means it produces too much thyroid stimulating hormone (TSH), so the thyroid gland produces an excess of thyroxine.
Secondary hyperthyroidism = high TSH, high thyroxine
What is tertiary hyperthyroidism?
When the pituitary is continuously producing TSH
Name three types of signaling in the body
Hormones, Ions, Electrical
Whats an autocrine cell?
A cell talking to itself
What is a paracrine cell?
Paracrine cells communicate with neighbouring cells, the signal diffuses across a short distance. This is local - so it doesn’t enter the blood stream.
What is an endocrine cell?
These cells communicate with other cells in the body. The endocrine cell releases a hormone into the blood stream till it reaches the target cell.
What are the six main hormones of the hypothalamus?
Gonadotrophin-releasing hormones (GnRH), growth hormone-releasing hormone (GHRH), Somatostatin (SS), Thyrotropin releasing hormone (TRH), Corticotropin-releasing hormone (CRH), Dopamine
What are the six main hormones of the Anterior Pituitary gland?
Folicle Stimulating Hormone (FSH), Lutenising hormone (LH), Growth Hormone (GH), Thyroid stimulating hormone (TSH), Prolactin, Arendocorticotrophic hormone (ACTH)
What are the two hormones of the Posterior pituitary gland?
Oxytocin (OT) and vasopressin (ADH)
Explain possible symptoms associated with (Hyper/hypo)natraemia
(Hyper/hypo)natraemia - Na+ levels, large component of ECF
Hypernatraemia - Over hydration -hypertension, elevated pulse (tachycardia), elevated temperature, elevated respiratory rate, fever, edema (may be pitting), dry skin, thirst, weakness etc
Hyponatraemia- could be due to addison’s disease, fever, diarrhea, vomiting, excessive use of diuretics
symptoms: increased pulse (tachycardia), weak, thready, peripheral pulses, flat neck veins, increased respiratory rate, decreased blood pressure (hypotension), decreased body weight, thick, slurred speech
Explain possible symptoms associated with (hyper/hypo)kalaemia,
(hyper/hypo)kalaemia - K+ levels, large component of ICF
Hyperkalaemia- could be due to Diarrhoea and vomiting, Diuretics, Hypomagnesaemia, Conn’s and Cushing’s
-can lead to Weakness and Cardiac dysrhythmia
Hypokalaemia -Decreased loss potassium, Renal failure, Diuretics/ACE inhibitors, Addison’s disease
-Could lead to cardiac arrest
Explain possible symptoms associated with (hyper/hypo)calcaemia
(hyper/hypo)calcaemia - ca+ levels
Hypercalcemia - often due to Hyperparathyroidism, can lead to impaired kidney function and weaker bones
symptoms: increased thirst and urination, belly pain, nausea, bone pain, muscle weakness, confusion, and fatigue.
hypocalcemia - often due to Vitamin D deficiency, Mg deficiency, Renal disease.
Symptoms: Most cases have no symptoms. In severe cases, symptoms include muscle cramps, confusion, and tingling in the lips and fingers
What is hyperparathyroidism
Primary hyperparathyroidism is a disorder of one or more of the parathyroid glands.
The parathyroid gland(s) becomes overactive and secretes excess amounts of parathyroid hormone (PTH).
PTH stimulates release of Ca from bones and retention in the kidneys. This often due to a tumour on the parathyroid glands or an abnormal enlargement on the gland.
= Joint aches, Fatigue, Weakness, loss of appetite, nausea, constipation, excessive thirst, or frequent urination
Overtime kidney function can be impaired as more ca+ is excreted due to the high levels, there is a higher risk of kidney stones due to the high Ca levels and risk of bone disease as the Ca+ is drawn out of them, reducing bone density.
(secondary hyperparathyroidism is when there are low ca levels so more PTH is secreted to retain more ca)
Energy values from carbohydrates
4kcal/g
Energy values from protein
4kcal/g
Energy values from lipids
9kcal/g
Energy values from alcohol (ethanol)
7kcal/g
How is fat stored within the body?
In adipose tissue
How are carbohydrates stored within the body?
As glycogen in the liver and muscles
How is protein stored within the body?
In the muscles
How is the total energy spend per day divided?
60% resting (BMR)
30% activity induced
10% dietary
What is the Phospholipid bilayer
Phospholipid bilayer is made up of two layers of lipid molecules
- Hydrophobic, or water-hating, core (fatty acids tails are nonpolar and therefore hydrophobic)
- Hydrophilic, or water-loving, exterior. (heads are polar and therefore hydrophilic)