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Nutrition 1 semester 2 > Proteins and amino acids > Flashcards

Proteins and amino acids Flashcards

1
Q

What percentage of body weight do proteins account for

A

17%

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2
Q

Of the 20 amino acids used by the body to code for proteins, how many are essential and what does this mean

A

9
They cannot be made by the body in sufficient quantities

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3
Q

which amino acid is debated as to whether it is essential or conditionally essential

A

Histidine - bacteria can produce it, though it is not clear how much is provided by intestinal bacteria.

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4
Q

What is unique about histidine

A

it is the only aa that does not impair protein synthesis when it is deficient in the diet - thus making it non essential

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5
Q

What might denature a protein

A

heat, heavy metals, pH, Alcohol

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6
Q

Each protein has a specific function that is determined during protein synthesis. Name 5 such functions

A

structure of body tissues (eg collagen)
Movement (actin and myosin fibres)
Carrier molecules (haemoglobin)
Storage molecule (Ferritin)
Fluid balance in blood (Albumin)
HOrmones (insulin) and cell membranes
Immune function (antibodies)
Clotting mechanisms
Alternative energy source

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7
Q

PROTEIN FUNCTIONS:
Growth and maintenance

A

proteins are the building blocks of muscles, blood, skin and body structures

Actin and myosin filaments involved in muscle contraction and are proteins

Collagen: forms bones and provides building materials for ligaments, tendons, blood vessels walls dermis

Proteins are needed for the replacment of cells - eg skin, GIT cells

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8
Q

PROTEIN FUNCTIONS:
Hormones and receptors
Some hormones are derived from cholesterol, others from amino acids. Provide examples

A

TYROSINE and iodine - thyroid hormones

TYROSINE (and B6) - dopamine, orephinephrine, epinephrine
TRYPTOPHAN - serotonin, melatonin

Insulin (2 polypeptide chains)
Glucagon, PTH, Calcitonin - (1 polypeptide chain)

Cell membrane proteins are receptors for hormones.

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9
Q

PROTEIN FUNCTIONS:
Enzymes - provide example

A

amylase

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10
Q

PROTEIN FUNCTIONS:
Immunoglobulins (antibodies)

What do they do and name the most abundant

A

found in blood and bodily fluids

They identify and neutralise foreign materials

IgG most abundant
IgA in body scretions
IgM the first to apprea in response to antigen exposure
IgE allergic reactions

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11
Q

PROTEIN FUNCTIONS:
Transport

A

Albumin - can bind to Ca, Zn and B6 as well as steroids and fatty acids
Transferrins bind to Fe
Ceruloplasmin binds to Cu
Haemoglobin transports oxygen in the blood

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12
Q

PROTEIN FUNCTIONS:
Buffers - how do they act as buffers and which two amino acids are the best buffers

A

Some aa have side chains that can easily pick-up or let go of hydrogen ions - helping to regulate the acid-base balance in body fluids

Proteins with lots of these aa are good buffers

Histidine is the best buffer at 7.35-7.45. Cysteine second!

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13
Q

PROTEIN FUNCTIONS:
Fluid balance - what happens if protein levels fall too low

Name two protein related causes of oedema

A

proteins attract water - the osmotic pressure from fluid is called ONCOTIC PRESSURE

If protein levels fall too low, water leaks out of the blood vessels and accumulates in interstitial spaces - OEDEMA

Protein related causes of oedema include:
- excessive protein losses due to kidney disease
- Inadequate protein synthesis due to liver disease
- inadequate dietary intake of protein (malnutrition) thence distended abdomen in worlds poorest countries

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14
Q

PROTEIN FUNCTIONS:
Glycoproteins (essential component of cell membranes - carb and protein)

A
  • Mucins - mucus and saliva for protective barrier
  • ABO blood type antigens
    HOrmones - Luteinising Hormone, FSH, TSH
  • Major histocompatability complex - cell surface receptors involved in adaptive immunity
  • Proteoglycans - bound to GAGs and found in extracellular matrix eg chondroitin sulphate found in cartilage - shock absorbs
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15
Q

PROTEIN METABOLISM
What does deamination involve and where does it take place

A

the removal of the nitrogen containing amino group
the liver

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16
Q

Why must deamination of amino acids take place

A

to enable them to be used as an energy source or stored as fat - the remaining fragments after the amine has been removed can be used to produce glucose or ketones

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17
Q

When the nitrogen group is removed from the amino acid, what toxic substance is formed

A

ammonia

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18
Q

PROTEIN SYNTHESIS: What cycle must ammonia go through to make it water-soluble and able to be excreted by the kidneys

A

the UREA cycle
Ammonia is converted to UREA in hepatocytes

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19
Q

PROTEIN SYNTHESIS: What is deamination and what can the remaining fragments of the amino acids be used to produce

A

the removal of the amine group from a protein

Glucose or ketones for energy or energy storage

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20
Q

PROTEIN SYNTHESIS: Describe the urea cycle and list the three amino acids involved in the cycle (THIS NEEDS CLARIFICATION)

A

Ammonia formed from deamination needs to be converted to urea to ensure its safe removal from the body.

The urea cycle is the sole endogenous source of the amino acids: arginine, citrulline and ornithine (liver support and detox agent)

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21
Q

PROTEIN SYNTHESIS: What does impairment of the urea cycle lead to

A

symptoms of hyperammonaemia, including :
chronic fatigue
headache
irritability
nausea and diarrhoea
poor concentration
confusion
intolerance of high protein foods

can lead to LIVER CIRRHOSIS

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22
Q

PROTEIN SYNTHESIS: describe Transamination and state what vitamin the process is dependent on

A

Important step in the synthesis of some NON ESSENTIAL amino acids. If a particular non essential aa is no available the body can make it from another.

The AMINO group of one aa is transferred onto an ENZYME. The enzyme transfers teh amino group onto a ketoacid, thus forming a NEW AA.

Process is B6 dependent. (sunflowers, green veg, walnuts, bananas, lentils, avo)

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23
Q

PROTEIN SYNTHESIS: what is PROTEIN TURNOVER

A

the process of proteins constantly being made a broken. e.g enzymes may be recycled in a matter of minutes

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24
Q

Describe the process of protein turnover

A

When proteins are broken down they free amino acids to join general circulation. These plus diet derived create an AMINO ACID POOL.

They are UTILISED or EXCRETED, but NOT stored.

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25
Q

Why is it important to have a regular supply of protein in the diet

A
  • They are not stored.
  • Essential aa have a longer half-life as they are more critical to the body in terms of supply.
  • Body will break-down its own tissue to obtain essential aa if can’t obtain from the “pool”
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26
Q

What impact can stress have on protein loss

A

Stress causes protein loss in areas such as skeletal muscle due to the catabolic actions of stress hormones.

Chronic stress impacts the framework of bones as protein losses can occur in the extracellular matrix (collagen). Think osteoporosis.

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27
Q

PROTEIN METABOLISM: When are proteins used for energy or energy storage

A

when gucose and fatty acids are limited - eg starvation, disease

But there’s no store so tissue components are broken down

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28
Q

Name endogenous sources of proteins

A

adults reabsorb 50g protein from shed mucosal cells and 17g from digestive enzymes and gycoproteins

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29
Q

What determines protein quality

A

digestibility and amino acid composition

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30
Q

What can influence the digestibility of protein

A

gut function (HCl/digestive enzymes)
Fibre
anti nutrient factors e.g. phytates and lectins

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31
Q

What improves the digestibility of plant protein sources

A

soaking, sprouting fermenting which can lower anti nutrient factors
The Fibre, prebiotics and phytonutrients can make plants a superior choice.

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32
Q

List ways in which protein digestion can be optimised

A

Chew thoroughly and don’t drink with meal

support stomach acid levels with Zn and B6 rich foods

Apple cider vinegar before meal

Bitter herbs before meal (watercress, gentian, barberry bark) promote release of pancreatic juice

BETAINE HYDROCHLORIDE SUPPLEMENTS 600mg - one when starting to eat increasing by one up to 5 unti feel warmth then cut back by 1 pill.

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33
Q

Protein quality - how does the microbiome contribute to protein metabolism and with what effects

A

undigested protein that reach the colon is fermented, creating toxic metabolites that increase inflammatory response and encourages proliferation of opportunistic pathogens

Effects include:
toxicity, nephrotoxicity, carcinogenesis

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34
Q

What is a limiting amino acid and name the 4

A

to make a protein a cell must have all the required amino acids available simultaneously. If one is missing it will cease making it or dismantle another protein to obtain it.

A limiting aa is one supplied in less than the amount needed for protein synthesis.

LYSINE
THREONINE
METHIONINE
TRYPTOPHAN

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35
Q

What is complete protein and name vegan examples

A

Food that contains all nine essential aa.

Quinoa, buckwheat, pumpkin seeds, chia seeds, hemp, tempeh

Meal, poultry, fish, eggs, dairy (not butter)

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36
Q

What is an incomplete protein

A

food that is low in one or more essential amino acids

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37
Q

Plant foods often have an incomplete amino acid profile, how can this be overcome

A

Plant foods can be combined to ensure the essential aa’s are combined. Eg
Legumes + nuts/seeds
Whole grains + legumes
Vegetables + grains

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38
Q

Do vegans/vegetarians need to combine all the amino acids in one meal

A

No - the amino acid pool is stable so they can eat a range of plants throughout the day

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39
Q

What are the drawbacks of animal protein

A

High in METHIONINE :
immune stimulating effect on T cells, leading to autoimmunity/chronic inflammation.
Excess methionine can lead to increased homocysteine = atherosclerosis

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40
Q

Name disease states associated with high long term animal protein intake

A

osteoporosis
kidney disease
increased cancer risk
liver disorder
atherosclerosis
increased muscle soreness post exercise

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41
Q

What % of calorie intake is a high level of protein considered to be

A

20%

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42
Q

Why should we promote plants as a good source of protein

A

because they buffer the acidic load of animal protein

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43
Q

EXCESS PROTEIN DISEASE STATES: name 4 and explain why

A

CANCER:
moderate and high intake of animal protein increase cancer risk.
Red meat is possible cause of cancer (WHO)
Processed is carcinogenic

SKELETAL DISEASE:
Acidic burden draws calcium out of bones - osteoporosis. Protein deficiency can also impact bone health due to collagen structure of bone

KIDNEY DISEASE:
extra acidity needs buffering by kidneys

CVD:
oxidation and inflammation in the endothelium

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44
Q

What compounds are produced during the high temps of cooking meat

A

Polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs) - CARCINOGENIC

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45
Q

What are the benefits of plant based protein

A

Less methionine and branch chain aa (predominant in meat) is beneficial to health
Protective against cancer, CVD, DM, autoimmunity due to phytonutrients, fibre and prebiotics
Protective against ageing as lower levels of LEUCINE, which can increase teh expression of TOR, an enzyme that regulates cell growth

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46
Q

What is TOR

A

Target of Rapamycin - enzyme that regulates cell growth

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47
Q

Protein requirements: what is the debate

A

Infants get their protein from breast milk where protein is low.
Determining requirements is difficult as no deficiency symptoms until severe
Deficiency would start at .4-.5g/kg body weight
Whole foods set a natural balance for protein intake as NO WHOLEFOOD IS PURELY PROTEIN

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48
Q

Why do athletes require more protein and what are the recommendations

A

increased catabolism of aa during exercise
Usual recommentation is .75g/kg weight
minimal exercise: 1
moderate: 1.3
intense: 1.6g

Should be met as a proportion of increased calorie intake

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49
Q

How do protein recommendations differ for pregnancy and lactation and vegans

A

pregnancy: add 6g day
lactating: 11g 0-6 months and 8g 6+months
Vegans: multiply by 1 to accommodate the lower protein bioavailability

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50
Q

Who is most likely to be affected by protein deficiency

A

Children and teens with western diet
older people due to immobility, dentition, digestive health
anorexia nervosa
recovering patients
Homeless and disadvantaged
drug and alcohol addicts
Chronic digestive conditions and use of PPIs
Chronic or active infections

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51
Q

In addition to being crucial for protein synthesis, AMINO ACIDS also

A

contribute to synthesis of hormones and neurotransmitters
act as neurotransmitters (glycine)
act as methyl donors (methionine)
build bile acids for digestion (glycine and taurine)
precursors for NO production (arginine)
help detoxify chemicals (phase II)
Precursors for the manufacture of endogenous antioxidants

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52
Q

How are amino acid levels in the body measured and in what circumstances is this useful

A

plasma and urine
useful in chronic fatigue syndrome due to mitochondrial ineffeciency or long term PPI use due to reduced aa absorption
Helpful in clinic as high levels of branched chain aa (leucine, valine, isoleucine) and homocysteine are linked to heart disease

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53
Q

EXPLAIN WHAT A COMPLETE PROTEIN IS AND PROVIDE THREE EXAMPLES OF FOODS THAT FIT THIS CATEGORY

A

contains all 9 essential amino acids
animal sources, quinoa, buckwheat, pumpkin seeds, chia seeds, hemp seeds, tempeh

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54
Q

Tyrosine is required for the formation of certain hormones, name 2

A

with iodine: thyroid hormones
dopamine, norepinephrine, epinephrine

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55
Q

WHY CAN OEDEMA OCCUR WHEN PROTEIN LEVELS FALL TOO LOW

A

PROTEINS ATTRACT WATER - THE PRESSURE FROM PROTEINS (E.G. ALBUMIN) IS CALLED ONCOTIC PRESSURE
IF PROTEINS FALL TOO LOW, WATER LEAKS OUT OF THE BLOOD VESSELS AND ACCUMULATES IN INTERSTITIAL SPACES = OEDEMA

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56
Q

WHAT IS THE IMPORTANCE OF TRANSAMINATION and what enzyme is it dependent on

A

Important step in synthesis of NON ESSENTIAL amino acids. If a particular one isn’t available, the body can make it from another.
The amino group of an aa is transferred onto an enzyme which transfers it onto a ketoacid, thus forming a new aa.
B6 (wholegrains, sunflower seeds, walnuts, bananas)

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57
Q

WHAT HAPPENS IN THE UREA CYCLE

A

ammonia formed by deamination (removal of the nitrogen containing amino group needs to be converted to urea for safe removal from teh body. Takes place in hepatocytes.

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58
Q

OUTLINED TWO WAYS TO OPTIMISE DIGESTION OF PROTEINS

A

CHEW thoroughly
support stomach acid levels - B6 and zinc rich foods/bitter fooods before meals

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59
Q

THE PROTEIN IN PLANT FOOD IS OFTEN DESCRIBED AS INCOMPLETE. WHY AND HOW CAN DIFFERENT FOODS BE COMBINED TO OVERCOME IT

A

plants do not contain complete proteins, they are deficient in one or more aa.
Nuts can be combined with legumes
Wholegrains, with legumes
Vegetables with grains

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60
Q

WHAT ARE THREE ADVERSE EFFECTS ASSOCIATED WITH LONG TERM HIGH INTAKE OF ANIMAL PROTEIN

A

Red meat is associated with certain cancers
Skeletal diseases eg osteoporosis due to calcium leached from bones to buffer the acid
Kidney disease - buffer acid and filter the increased urea that’s generated
CVD - oxidation and inflammation

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61
Q

GLUTAMINE

A
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62
Q

What is the most abundant amino acid in the body

A

Glutamine - 60% of total pool of amino acids

63
Q

What is the role of glutamine and the intestinal barrier and what diseases can cause intestinal permeability

A

Primary amino acid source for intestinal cells and helps regulate tight junction integrity and enterocyte proliferation. Depletion = intestinal permeability.

64
Q

INTESTINAL PERMEABILITY: what diseases can cause intestinal permeability
What can leak into the blood

A

Intestinal permeability linked with coeliac, IBD, candidiasis, food allergies, chemo
LPS - lipopolysaccharides (released from the cell walls when they die) which can lead to chronic disease/autoimmunity

65
Q

What is the preferred amino acid for rapidly dividing cells such as enterocytes (gut) and lymphocytes and macrophages (immunity)

A

glutamine

66
Q

When is glutamine synthesis imparied

A

acute stress (injury/infections), therefore CONDITIONALLY ESSENTIAL.

67
Q

List out ways in which we can naturally support the intestinal permeability

A

remove the cause and supply nutrients that support enterocyte junctions:
Glutamine supplementation (10g/day)
Glutamine rich foods (cabbage juice, spirulina, broccoli, cod, salmon)
Zinc (rapid cell division and tight junction support)
Antioxidants (C E beta-carotene)
Herbs (marshmallow, slippery elm, goldenseal
Bone broth (collagen, glucosamine, chondroitin, glycine)
Quercitin
N acetyl glucosamine

68
Q

Name a key role of glutamine in the body

A

acts as a buffer, receiving excess ammonia (nitrogen) and releasing it when needed to form other amino acids and nucleic acids

69
Q

What type of cells is glutamine the preferred source for

A

rapidly dividing cells such as enterocytes (gut) and lymphocytes and macrophages.

70
Q

List four functions and therapeutic uses of glutamine

A

Immunity: SUpport lymphocyte and macrophage proliferation.
Therapeutic Use: recurrent infections/compromised immunity

Hypoglycaemia: substrate for gluconeogenesis
Therapeutic use:
2tsp in water between meals in place of snacks while adapting to healthier eating

Muscle recovery: promotes faster recover and reduces muscle breakdown
Therapeutic use: exercise recovery/sports nutrition

Neurotransmitter: its converted to glutamate (excitatory) then GABA (inhibitory). Requires B6, taurine and Zn.
Therapeutic use: if conversion is working, supplementation can help anxiety and sleep.

HIV support due to intestinal, muscle and immune support functions.

71
Q

What are the guidelines for glutamine supplementation inculding:
dose
drug interactions
toxicity
caution

A

Start low and gradually increase.
10-30g/day ideally AM.
Breaks down rapidly so consume asap.

Drug interactions: anti seizure meds
Toxicity: no adverse in short term dosing up to 50-60mg/day
CAUTION: cancer cells use glutamine to fuel growth and metabolism
avoid in cancer, epilepsy, liver and kidney disease

72
Q

CYSTEINE:
what amino acids is cysteine formed from, where made and what co factors

A

methionine and serine
the liver
B6 B9 B12

73
Q

Name food sources of cysteine

A

Legumes, sunflower seeds, eggs, chicken

74
Q

What amino acids are components of glutathione and which is the rate limiting a.a

A

CYSTEINE, glutamic acid, glycine

75
Q

Name three compounds that cysteine is a component of

A

glutathione
co-enzyme A
taurine

76
Q

why is cysteine important for detoxification and antioxidant support

A

it is the rate limiting a.a. in the synthesis of glutathione
It is the source of sulphate, used in phase II liver detoxification pathway sulfation 9used for many drugs, steroid hormones), increasing water solubility for their excretion.

77
Q

N-ACETYL CYSTEINE (NAC): what is it

A

a derivative of L-cysteine. Used in supplementation as easier to absorb

78
Q

list four functions and therapeutic uses of N-acetyl Cysteine (NAC)

A
  1. liver detox/antioxidant. Building block of glutathione; role in building antiox defences. Crucial in drug metabolism in the liver (drugs deplete glutathione, cysteine depletes it)
    Therapeutic use: liver support/heavy metal detox. Healthy aging. Ulcerative colitis
  2. Reproductive health: increase sperm concentration, benefits serum testosterone
    Therapeutic use: infertility
  3. respiratory health: Expectorant properties (breaks-up mucus for easier elimination from respiratory tract.
    Therapeutic use: respiratory infections, cystic fibrosis, asthma
  4. Insulin resistance: increases insulin sensitivity:
    Therapeutic use: DM. PCOS

HIV support (increased glutathione); Neurodegenerative diseases Parkinsons, alzheimers

79
Q

N-Acetyl Cysteine
Application in hospital setting
dosage
drug interactions
caution

A

antidote to paracetamol toxicity from OD
Dose: 600mg-1.5g/day
Drug interactions: Nitro-glycerine and insulin
Caution: can cause adverse GI effects

80
Q

METHIONINE - what type of a.a. is it

A

sulphur containing ESSENTIAL

81
Q

name food sources of methionine

A

high in animal foods - eggs, beef, chicken.
brazil nuts, sunflower seeds, beans, whole grains

82
Q

what is the main function of methionine

A

a major METHYL donor in teh body for methylation reactions eg the homocysteine cycle and phase 2 liver detox.

83
Q

What is the effect on the body of raised homocysteine

A

damages the vascular endothelium, increases risk of atherosclerosis and miscarriage

84
Q

what vitamins support methylation whilst restricting dietary methionine (animal) to lower homocysteine

A

B6 folate B12

85
Q

What caution must be exercised around methionine levels in the body

A

excess methionine also increases acidity in the body

86
Q

CARNITINE:
what amino acids can it be synthesised from

A

methionine and lysine. Can also be obtained from diet.

87
Q

What vitamins and minerals is carnitine production dependent upon

A

iron, C B3 B6

88
Q

How common is deficiency of carnitine

A

rare as body can make it - results from errors of metabolism

89
Q

When would carnitine become conditionally essential

A

in a mutation of the SLC22A5 gene

90
Q

Name food sources of carnitine

A

nuts, seeds, avocado, asparagus, spinach, red meat, diary

91
Q

List ONE function of carnitine and therapeutic uses

A

Assists ATP synthesis from fatty acids: facilitates transport of long chain fatty acids across the mitochondrial cell membrane so they can be oxidised to create ATP.
Acts as antioxidant and removes potentially toxic metabolites out of mitochondria.
THERAPEUTIC USES: hyperthyroidism as acts as thyroid hormone antagonist.
weight loss
heart failure
infertility - improves sperm count and motility
Fatigue and concentration
Athletic performance
ADHD

92
Q

CARNITINE supplementation:
dose
drug interactions
caution

A

1-2g twice day
drug interactions: with warfarin will increase blood thinning effects.
contraindicated with hypothyroidism (thyroid hormone antagonist)
Caution: at HIGH doses: nausea, vomiting, abdominal cramps, heartburn, gastritis
Urine, sweat, breath - fishy odour

93
Q

CREATINE: name the three amino acids its made of and where formed

A

arginine, glycine, methionine. Formed in liver, kidneys and pancreas

94
Q

Where is creatine found and what is one of its key functions

A

95% in muscles (some in brain)

Creatine phosphate is a fast source of ATP

95
Q

List the main function of creatine and therapeutic uses

A

storage form of ATP: enables explosive power in the muscles for 8-12 seconds.
Enhances skeletal and cardiac muscle
THERAPEUTIC USE: enhance muscular performance (esp HIT)
Heart failure and coronary artery disease

96
Q

Why should creatine supplementation be reduced over time

A

Skeletal muscle has a saturation point, therefore if a weight trainer supplements for 5 days of .3g/kg body weight for 5 days, they would reduce it down to .03. (front loading - half before work out and half after)

97
Q

Name the drug interactions and cautions around creatine supplementation

A

Caffeine, ephedra and creatine may lead to ischaemic stroke.
High doses may affect renal function.
NSAIDS and antibiotics may have harmful effect on kidney function
CAUTION: can cause abdominal pain, nausea, diarrhoea, palpitations, cramping.

Creatine draws water from the rest of your body - therefore HYDRATE

98
Q

GLYCINE: name food sources

A

legumes, seaweed, spinach, kale, cauliflower, cabbage, banana, pumpkin, bone broth, meat, fish, eggs

99
Q

What compounds is glycine required for the synthesis of

A

haem, DNA, RNA, bile acids, gultatione, creatine, skin, connective tissue.

100
Q

What vitamin and aa is required to make gycine

A

B6 and serine

101
Q

Glycine is conditionally essential in the case of certain metabolic stresses, provide examples of these

A

Increased haem synthesis for blood formation
Collagen formation for growth and repair
Glycine conjugation in detoxification

102
Q

Name three functions and the therapeutic uses of GLYCINE

A
  1. COLLAGEN SYNTHESIS - collagen is the most abundant protein in the body - 1/3 glycine. Crucial for bones, dermis, GIT, tendons, ligaments
    THERAPEUTIC USES: GIT repair (IBD, leaky gut) Skin
  2. LIVER DETOX - required to conjugate toxins in phase 2 liver detox.
    Component of glutathione and bile acids
    THERAPEUTIC USE: liver support, digestion
  3. NEUROTRANSMITTERS: it’s inhibitory in the CNS and reversibly converted to serine and used to form acetylcholine.
    THERAPEUTIC USE: insomnia; cognition, memory and learning
103
Q

TAURINE: What vitamin and aa are needed for it synthesis

A

B6 and cysteine

104
Q

Under what circumstances might taurine synthesis be inhibited

A

extreme stress and illness

105
Q

Name food sources of taurine

A

ONLY animal, esp chicken and turkey thighs and fish and breast milk

106
Q

Why is supplementation of taurine necessary in non-breastfed infants

A

because their ability to synthesise taurine is underdeveloped

107
Q

List 5 functions of TAURINE and therapeutic uses

A
  1. Muscle health: Highly concentrated in muscles - imp role in contraction. Also heart health as anti inflammatory and BP lowering properties
    THERAPEUTIC USE: heart failure, hypertension, Duchenne, Sarcopenia
  2. Antioxidant. Protects mitochondria from ROS. Taurine is high in neutrophils and it provides anit-inflamm and antiox effects
    THERAPEUTIC USE: atherosclerosis; infertility (sperm health)
  3. Neurological: inhibitory neurotransmitter (agonist of GABA receptors in the CNS). Supports development of the cerebellum
    THERAPEUTIC USE: Parkinsons, epilepsy, insomnia
  4. Bile: bile acid conjugation
    THERAPEUTIC USE: supports liver detox. Digestive support (fats)
  5. Insulin: improves insulin resistance
    THERAPEUTIC USE: DM
108
Q

TAURINE dose, drug interactions, contraindicated, toxicity, caution

A

Dose: 500mg 3x dat
Drug interactions: Lithium and blood pressure meds
Contraindicated: bipolar disorder
Caution: added to energy drinks but its NOT a good source due to all the additives

109
Q

THEANINE (calming/sleep)
non essential
Why is it beneficial in green tea

A

it counteracts the bitterness of green and black tea, and reduces the negative effects of caffeine by. having opposing effects (relax not stimulate)

110
Q

What amino acid is uniquely found in green tea?

A

theanine

111
Q

Name one function of theanine and its therapeutic uses

A

NEUROLOGICAL CALMING it crosses the blood brain barrier and blocks GLUTAMATE receptors whilst increasing GABA activity (which is calming); increases alpha brain waves, producing mood enhancing effect without drowsiness. INcrease dopamine and serotonin levels
THERAPEUTIC USE: increased concentration; anxiety, stress, insomnia, low mood, hypertension

Good for nerudiverse/ADHD

112
Q

What is a therapeutic dose of THEANINE; drug interactions and adverse effects

A

50mg-200mg (green tea not practical source, just 20mg in average Japanese drinker day)
Drug interactions: lower BP therefore don’t use with anyi-hypertensives
Adverse effects: headache/sleepiness

113
Q

TYROSINE: conditionally essential. What aa is it derived from
(great for focus and mood)

A

Phenylalanine

114
Q

Name food sources of TYROSINE

A

nuts, seeds, legumes, whole grains, fish, meat, poultry

115
Q

List one function and therapeutic uses of TYROSINE

A

ENdocrine health: precursor to THYROID hormones, dopamine, epinephrine, noradrenaline. Precursor to melanin.
THERAPEUTIC USE: Adrenal fatigue, hypothyroidism, ADHD, depression, anxiety, cognition

116
Q

Tyrosine supplementation
Dosage
Drug interactions
Contraindicated
Caution

A

Dose: 400-6000mg/day. High dose safe up to 3 months

Drug interactions: MAOI antidepressants (MAO deactivates dopamine) levidopa, thyroxine

Contraindicated: overactive thyroid, might increase thyroxine levels worsening hyperthyroidism.
Melanoma.

Caution: high dose GIT upset

117
Q

TRYPTOPHAN essential or not?
Name food sources

A

Essential
Brown rice, turkey, pumpkin seeds, oats, bananas, quinoa, fish, eggs

118
Q

Name 2 functions and therapeutic uses of tryptophan

A
  1. ENDOCRINE HEALTH: used for serotonin and melatonin synthesis. INSULIN assists it across the BBB. If supplementing consume with carbs.
    THERAPEUTIC USE: depression, insomnia, stress, anxiety , PMS, weight control, smoking addiction
  2. ATP synthesis: needed to make B3 which is needed for 2 coenzymes NAD NADP in ATP production.
    THERAPEUTIC USE: fatigue, fibromyalgia, Alzheimer’s.
119
Q

Why is tryptophan of interest for athlete and anti aging studies

A

Enhances release of growth hormones.

120
Q

Tryptophan supplementation
Dose
Drug interactions
Adverse effects

A

Dose: 100-600mg/day. 5HTP is usually preferred as it cannot be used for anything other than serotonin and melatonin production.

Drug interactions: antidepressants, sedatives
Adverse effects l-tryptophan can cause some GIT disturbances.

121
Q

PHENYLALANINE
essential?
Food sources?

A

Essential.
Avocado, brown rice, lentils, eggs, fish, meat, soy.

122
Q

Name two functions of phenylaline

A

1 endocrine health : can be converted to TYROSINE which is used to make thyroid hormones, dopamine etc
Therapeutic use: depression, cognition., Parkinson.
2 skin pigmentation : melanin production (via tyrosine pathway)
Therapeutic use: vitiligo (50mg/kg to 100 mg/kg 6-18 months)

123
Q

Phenylalanine
Dose
Drug interactions
Caution
Contraindication

A

Dose: 150-7000mg/day
Drug interactions : antipsychotics , neuroleptics
Caution: can worsen schizophrenia symptoms
Contraindications: phenylketouria

124
Q

Lysine
Essential?
Food sources

A

Essential
Quinoa, legumes, tempeh, chicken eggs dairy fish red meat

125
Q

What is the sister amino acid to lysine

A

Arginine. They compete for absorption

126
Q

Name dietary sources of Arginine

A

Nuts seeds seaweed meat

127
Q

What is the key therapeutic use of lysine

A

herpes simplex virus - prevents and fights outbreaks.

128
Q

What amino acid can be used for the prevention of cold sores and what vitmin can enhance its action

A

Lysine
vitamin C

129
Q

What amino acid does the herpes simplex use to replicate

A

arginine. therefore as lysine competes with lysine for absorption, increasing lysine can limit viral replication

130
Q

List three functions and therapeutic uses of lysine

A
  1. STRUCTURE: forms part of collagen - therefore plays role in tissue repair and bodily structure. Builds muscular tissue
    THERAPEUTIC USE: recovery from muscle injury, osteoporosis
  2. ABSORPTION: aids intestinal absorption of Ca, Fe and Zn
    THERAPEUTIC USE: osteoporosis, hair loss , anaemia
  3. GLUCOSE LOWERING EFFECT
    THERAPEUTIC USE: hyperglycaemia and DM
131
Q

Name the function and therapeutic uses of arginine

A

Precursor to NITRIC OXIDE - vasodilator and lowers BP.
THERAPEUTIC USE: hypertension, CVD, sports performance (increase blood flow to muscle), erectile dysfunction

132
Q

Dose and drug interactions of arginine
What does arginine compete with for absorption

A

6-12 g day
Competes with lysine and histidine - so don’t supplement with food.
Drug interaction: GTN spray (angina); anti hypertensives

133
Q

General guidelines for protein supplementation :
when should it not be advised to supplement
what might inhibit absorption and how can you enchance absorption

A

avoid in pregnancy and breastfeeding
Proteins compete with each other at the cell surface for absorption - use just one aa at a time
Long term can lead to imbalance

134
Q

Name functions in the body that can be restored by providing amino acids

A

Neurotransmitter and hormone synthesis
physical and immunologic barriers in the gut can be restored
Blood glucose can be stabilised through better gluconeogenesis (glutamine)
improved mitochondrial performance and therefore utilisaiton of fatty acids for energy
Hepatic and gastrointestinal detoxification reactions improved - amino acids required for conjugation reactions are available
Oxidative damage is reduced when sulphur amino acid supply is adequate to maintain glutathione (eg cysteine, glycine, glutamine)

135
Q

What amino acids are required for glutathione production

A

cyteine, glycine, glutamine

136
Q

What amino acid is needed for transport of fatty acids across mitochondrial cell membrane

A

carnitine

137
Q

what amino acids are needed for detoxification / conjugation reactions

A

glycine - needed for glutathione (liver detox), bile acids, and to conjugate toxins in phase II
glutamine
taurine
Cysteine (the rate limiting aa for glutathione synthesis)
Methionine (major methyl donor important for phase II liver detox)

138
Q

What amino acids can be used to stabilise blood sugars

A

glutamine,
cysteine (increase insulin sensitivity),
taurine (reduce insulin resistance)
Lysine - glucose lowering effect

139
Q

What amino acids can restore the gut

A

Glutamine (primary amino acid source for intestinal cells/regulate tight junction integrity)

140
Q

What amino acids can be used for hyperthyroidism or hypothryoidism

A

carnitine - acts as a peripheral thyroid hormone antagonist, therefore used for hyperthyroidism
Tyrosine - precursor to thyroid hormones - hypothyroidism
Phenylalanine - can be converted to tyrosine … thyroid hormones

141
Q

What amino acids are used for athletes/sports performance

A

Creatine: found in muscles and functions as fast source of ATP (creatine phosphate)
Taurine - muscle contraction

142
Q

What amino acid is neurologically calming

A

Theanine - crosses the BBB and blocks glutamate receptors and increases GABA activity

143
Q

what amino acid supports vitiligo

A

phenylalanine

144
Q

What is a major reason for impaired UTILISATION of amino acids

A

lack of micronutrients needed for interconversions eg zinc, B6 B12. Therefore always address the diet first

145
Q

What are free-form amino acid formulas

A

their free (non-peptide linked) form are efficiently absorbed, even in absence of stomach acid pancreatic secretions.
They provide balance of amino acids needed in pre digested form.
Add to juice for flavour.

146
Q

Suggest an amino acid and dosage for: 30 year old woman with low mood, poor sleep and carbohydrate cravings and PMS

A

Tryptophan.
100-600mg

147
Q

What amino acid is used for serotonin and melatonin synthesis

A

Tryptophan

148
Q

Why does low serotonin cause carbohydrate cravings

A

serotonin is synthesised from tryptophan which needs insulin to cross the BBB

149
Q

Suggest an amino acid and dosage for: a 65 kg woman with vitiligo

A

Phenylaline.
50mg/kg =

150
Q

Suggest an amino acid and dosage for: 25 year old man with recurrent cold sore outbreaks

A

Lysine, inhibits viral replication
300-3000mg

151
Q

Suggest an amino acid and dosage for: 18 year old student stressed about exams

A

Theanine, calms the nervous system without causing drowsiness

152
Q

Suggest an amino acid and dosage for: middle aged man with fatigue and lack of motivation due to stressful job

A

Tyrosine - increases production of dopamine which is associated with lack of motivation. Supports the adrenals

153
Q

Suggest an amino acid and dosage for: 40 year old woman with hyperthyroidism

A

Carnitine - thyroid hormone antagonist (blocks)

154
Q

Suggest an amino acid and dosage for: 55 year old overweight man with hypertension.

A

Arginine - precursor to nitric oxide therefore vasodilator therefore lowers BP. Good for sports performance, erectile dysfunction CVD, hypertension
6-12g

or
Taurine, lowers BP
1500mg day in 3 divided doses

Carnitine for weight loss but must be combined with physical activity

Nutrition 1 semester 2 (11 decks)

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