April Flashcards
Proteins and lipids (122 cards)
1
Q
What are the functional groups of amino acids?
A
- amino group (NH2)
- carboxyl group
- R-group
2
Q
How many types of amino acids does the human body use?
A
20
3
Q
How many amino acids that the body uses can it not synthesise (on insufficient quantities) ?
A
9
4
Q
Why are animal proteins complete proteins?
A
They contain all nine of the essential amino acids
5
Q
What are the essential amino acids?
A
PVT TIM HiLL
Phenylalanine, Valine, Threonine, Tryptophan, Isoleucine, Methionine, Histidine, Leucine, Lysine
6
Q
Is histidine an essential amino acid?
A
In infants yes
In adults, intestinal bacteria can produce it and it can be released from muscles. but not in large enough quantities
7
Q
Give an example of a protein used for movement
A
actin/myosin
8
Q
Give an example of a protein used for storage
A
ferritin
9
Q
Give an example of a protein used as a carrier molecule
A
Haemoglobin
10
Q
Which amino acid forms the basis of thyroid hormones?
A
Tyrosine
11
Q
Which amino acid forms the basis for epinephrine/norepinephrine and dopamine?
A
Tyrosine
12
Q
Which amino acid forms the basis for serotonin and melatonin?
A
Tryptophan
13
Q
Name 5 protein-based hormones
A
thyroid, insulin, glucagon, PTH, calcitonin
14
Q
Name 8 functions of proteins
A
enzymes, hormones, immunoglobulins, water balance (albumin), structure, transport, storage, buffers
15
Q
What are the functions of albumin?
A
to bind to calcium, zinc and B6 (plus steroids and fatty acids) to transport around the body. It helps maintain water osmolarity
16
Q
Which amino acids work as buffers in the human body?
A
histidine (releases hydrogen ions)
cysteine
17
Q
What is oncotic pressure?
A
The osmotic pressure causes by proteins in the body such as albumin
18
Q
What are the clinical manifestations of low protein?
A
oedema
19
Q
Give 6 examples of glycoproteins
A
mucins, ABO blood antigens, LH, FSH, TSH, major histocompatibility complex
20
Q
What is the role of proteoglycans?
A
They draw fluid to help with shock absorption, particularly in joints
21
Q
When does deamination of proteins occur in the body?
A
liver
22
Q
What is the purpose of the urea cycle?
A
To convert ammonia to urea, occurs in hepatocytes (creates arginine, citrulline and orthnithine)
23
Q
What are the symptoms of high levels of ammonia in the blood?
A
fatigue, headache, irritability, nausea, diarrhoea, confusion, intolerance to high protein foods
24
Q
Which vitamin is essential for transamination?
A
Vitamin B6
25
How are amino acids stored?
They are not, they circulate in the bloodstream for a limited amount of time
26
What factors will increase protein turnover?
Stress - uses proteins quicker, can cause osteoporosis
27
How much protein is reabsorbed each day?
around 70g
28
What ways can be used to optimise protein digestion?
- chew and avoid drinking with meals
- support stomach acid levels (Zinc and B6 for HCl production)
- bitters, apple cider vinegar, betaine hydrochloride
29
What is the issue with undigested proteins reaching the small intestine?
they become fermented releasing ammonia, amines, sulphides, can also be a breeding ground for pathogenic bacteria
30
Which amino acids are the limiting amino acids?
Lysine, threonine, methionine and tryptophan
31
Which plant foods are complete proteins?
quinoa, buckwheat, pumpkin seeds, chia seeds, hemp seeds, tempeh
32
Over what time period should you combine plant foods to get all essential amino acids?
Over a day
33
What can be an issue with consuming too much animal protein?
High methionine, which can stimulate T cells leading to inflammation and autoimmunity, and can increase levels of homocysteine. high pesticides/abx
34
What is considered a high protein diet?
> 20% of calorie intake from protein
35
What is the issue with cooking meats at high temperatures?
polycyclic aromatic hydrocarbons and heterocycline amines can be produced if meat is heated at high temperatures - carcinogenic
36
Why can high meat consumption lead to osteoporosis?
Creates a more acidotic body which can draw calcium out of bones
37
How much protein in breast milk?
9g per L, 38g fat per L
38
What is the lowest level of protein needed to prevent deficiency?
less than 0.4-0.5g/kg of body weight.
General recommended amount = 0.75g/kg
39
What are the protein needs for athletes?
1.3g/kg for moderate exercise
1.6g/kg for intense exercise
add extra 6g a day in pregnancy
add extra 11g a day in lactating people
40
Which amino acids are branched chain?
leucine, isoleucine and valine - can be linked to increase CVD
41
What is transamination?
Another amino acid can be turned into one that is more useful for a specific circumstance
42
What is the urea cycle?
ammonia is removed from protein which goes through the cycle to then make urea
43
What are the features of glutamine?
most abundant amino acid (60%), preferred fuels for enterocytes and helps with tight junctions and immune cells - increased need in times of stress. can be used for hypoglycaemia to stimulate gluconeogenesis, and muscle recovery, can make glutamate and GABA
44
What nutrients can be used to support tight junctions?
glutamine (cabbage, broccoli, fish), N-acetyl glucosamine, quercetin, zinc, marshmallow, slippery elm, bone broth
45
What is the dosage for glutamine?
1-30g a day, in the morning, build slowly. (don't use in cancer patients or with seizure meds)
46
What are the uses of cysteine in the body?
used to make glutathione, Co-enzyme A and taurine, binds to sulfur
47
Which food sources are high in cysteine?
legumes, sunflower seeds, eggs, chicken
48
What are the functions of NAC?
- building block of glutathione, crucial in drug metabolism
- increases sperm count, and testosterone
- helps with mucus elimination
- increases insulin sensitivity
- Paracetamol overdose
49
What are the functions of methionine?
A methyl donor, can help with phase 2 liver detox and raises homocysteine levels
50
What can be the issues with too much homocysteine?
damages endothelium and increases risk of atherosclerosis and miscarriage
51
What are the therapeutic uses of carnitine?
thyroid hormone antagonist in the peripheries - can be used to help with symptoms of hyperthyroidism.
Can help with ATP synthesis
52
Which food sources are high in carnitine?
nuts, seeds, avocado, red meat, dairy - can also be made in the body but requires iron, vit C, B3, B6
53
What are the two forms of carnitine supplementation?
L-carnitine - anti-coagulant, reduces thyroid levels
N-acetyl-carnitine - better brain effects
(s/e: can cause breath and sweat to smell like fish)
54
Where can you get creatine in the diet?
Meat, fish, eggs
55
What are the functions/benefits of creatine?
enables explosive power - can help with muscular power. May also help in CVD - it is the first molecule depleted in cardiac ischaemia.
- caution in poor kidney function
56
When is glycine a conditionally essential amino acid?
increased haem synthesis, collagen formation, detox, low B6 or serine
57
What are the therapeutic uses for glycine?
- collagen formation (skin, msk, GI)
- liver detox
- inhibitory neurotransmitter
58
What are the sources of Taurine?
only animal sources - chicken/turkey/fish, breast milk. Also can be synthesised by the body
59
What are the therapeutic uses of taurine?
- assists muscle contraction, anti-inflammatory, anti-oxidant, lowers BP. GABA agonist (sleep, parkinsons, epilepsy). bile acid conjugation. improves insulin resistance
60
Which medications interact with taurine?
Lithium (can decrease excretion), BP lowering medications.
61
What are the therapeutic effects of theanine?
reduces the negative effects of caffeine, blocks glutamate and increases GABA, can improve mood, can reduce BP - calms nervous system but does not cause drowsiness
62
What are the therapeutic doses for theanine?
50-200mg (about 20mg in green tea), can reduce BP
63
When is Tyrosine useful therapeutically?
precursor to thyroid hormones, adrenaline, dopamine, melanin.
64
What is the therapeutic dosage for tyrosine?
400-6000mg/day. Interacts with MAOIs, levodopa and thyroxine. contraindicated in melanoma
65
What are the therapeutic uses of trypotophan?
Used for serotonin and melatonin synthesis, (crosses BBB with insulin - take with carbs), ATP synthesis - through production of vit B3. May enhance release of growth hormone helping with healthy ageing
66
What is the therapeutic dose of tryptophan?
100-600mg/day. (5-HTP is preferred as it can only be used for serotonin and melatonin production).
Contraindications: SSRIs, benzos, tramadol. Can cause anticholinergic side effects and SSRI ones.
67
What are the therapeutic uses of phenylalanine?
Can be converted to tyrosine (to make thyroid hormones and dopamine), can help with melanin production via tyrosine pathway
68
What are the therapeutic effects of lysine?
Helps with Cold sores (herpes simplex) - effective with vit C. competes for absorption with arginine. plays part in collagen, aids absorption of calcium, iron and zinc, can lower glucose
69
What are the therapeutic uses of arginine?
Precursor to nitric oxide - can help with ED, hypertension, CVD
70
When should caution be used when supplementing individual amino acids?
in pregnancy or breastfeeding (not studied yet), if long term, if the amino acid competes for another for absorption
71
Glutathione is made up using which combination of amino acids?
Cysteine, glutamic acid and glycine
72
Who was the person who started the train of low fat diets?
Ancel Keys - said high saturated fats would increase serum cholesterol and lead to heart disease
73
What are the functions of white adipose tissue?
Secretion of growth factors, steroid hormones, enzymes and cytokines, to protect organs, store energy and provide insulation
74
What is the composition of fatty acids?
Hydrocarbons with an acid group at one end and methyl group at the other
75
What are the lengths of different fatty acids?
Short - up to 5 carbons
medium 6-12
long 13-22
very long 22+
76
Name three short chain fatty acids?
Acetate, propionate and butyrate
77
What is a trans fat?
A fatty acid that has been hydrogenated - turned from unsaturated to saturated
(C=C with H atoms on other sides of bonds)
78
What are the properties of different fats at room temperature?
Sat fats - solid
Unsaturated = liquid
The more double bonds, the less stable
79
What are the issues with ingesting trans fats?
They stiffen cell membranes, making them prone to oxidation. they increase LDL and triglycerides, insulin resistance, cancer and CVD
80
What are triglycerides?
A glycerol backbone with three fatty acids, they are the form of fat used for storage. high triglycerides can cause atherosclerosis
81
What is the process of lipogenesis?
Acetyl-CoA is made from glucose during glycolysis, this is then converted to triglycerides. occurs in liver and adipocytes mainly
82
Which hormones stimulate lipolysis?
Adrenaline, noradrenaline, ACTH, glucagon and growth hormone, TSH
(insulin antagonises it)
83
Which molecule is required for transporting fatty acids across the cell membrane?
Carnitine - fatty acids can then get into cells, undergo beta oxidation and be broken into energy
84
What molecule is the precursor of ketones?
Acetyl-CoA
85
Name two common ketones
acetoacetate, beta-hydroxybutyrate, acetone
86
When does ketosis occur?
When carbohydrates are restricted to less than 40g-20g per day
87
Where are lipases released?
Stomach and duodenum (pancreatic lipase)
88
What do lipases do?
Separate triglycerides into glycerol and fatty acids
89
How do you improve lipid digestion?
- chew
- take bitter foods before food
- zinc and B6 foods to help with HCl production
- increase glycerine and taurine which are components of bile
- choleretics (increase bile flow): dandelion, artichoke and turmeric
90
What are the recommended amounts of dietary fat?
Total: 20-35% of energy, 44-78g
saturates: no more than 10%/22g
unsaturated fats: 6-11%, 13-24g
omega 3: 1.1-4.4g
91
What are some good sources of healthy dietary fats?
Avocado, olives, seeds (chia flax, pumpkin, hemp, sunflower, almond, cashews, walnut, brazil nuts, walnuts, coconut milk, grass-fed meat, oily fish, cold pressed oils
92
What are the benefits of coconut oil?
Medium-chain triglycerides - used as fuel through ketogenesis
- antipathogenic properties (lauric acid)
- high HDL, low LDL
93
What is omega-9?
Oleic acid, high in olive oil.
Helps prevent atherosclerosis
94
What is omega-7?
Palmitoleic acid. Helpful for skin conditions and vaginal atrophy
95
What are the polyunsaturated fats?
Omega-3s
Alpha-linoleic acid, stearidonic acid, EPA and DHA
Omega 6s
Linoleic acid, Gamma linolenic acid, arachidonic acid
96
What are some good sources of alpha-linoleic acid?
Flaxseeds, chia seeds, hemp, pumpkin seeds, soybean, walnuts, wheat germ, dark leafy greens
97
What are some good sources of EPA and DHA?
cold water fish, oily fish, spirulina, chlorella, human breast milk
98
What are some good sources of omega 6s?
LA: safflower, sunflower, hemp, soy bean, sesame, pumpkin
GLA: borage, evening primrose, hemp oil, blackcurrant seed oil
AA: Meat, eggs, dairy
99
Which fats can be used for cooking?
coconut oil, butter and ghee
100
Which oils can be warmed but not heated above 180?
Extra-virgin olive oil, avocado oil and macadamia
101
Which oils should not be heated?
polyunsaturated fats like vegetable oils and seed oils
102
How should oils be stored?
In the fridge or freezer in a dark bottle - to prevent oxidation and production of malondialdehyde
103
Which two acids are essential fatty acids?
Linoleic acid (an omega-6) and Alpha-linoleic acid (an omega-3)
104
What are the therapeutic uses of ALA?
- reduce atherosclerosis
- reduce CRP and inflammation
- Anti-arrhythmogenic
- Anti-hypertensive (lower ACE activity), and vasodilatory effect in brain
- Can lower LDL cholesterol
- Can help in depression
105
Which medications do ALA interact with?
Warfarin - increases anti-coagulant effects
Statins - can increase effect of statins
106
What are the therapeutic uses of EPA and DHA?
- Can reduce triglyceride levels, lower BP, prevents atherosclerosis
- anti-inflammatory (inhibits NFkB, TNF-a, IL6)
- neuroprotective
- brain development in foetus
107
What are the therapeutic uses of Gamma-Linoleic Acid?
- reduces joint pain in RA
- can improve attention in ADHD
- Improves skin symptoms in eczema
108
What are the benefits of evening primrose oil?
abundant in LA and GLA
- helps with PMS (inhibits prolactin) and fertility
109
What are the interactions with GLA?
- chemo - can increase S/E
- cyclosporine - can increase immunosuppression
- NSAIDs can counter effects of GLA
- May increase risk of seizures
110
What are the effects of arachidonic acid?
Can turn into inflammatory prostaglandins which cause fever, vascular permeability, swelling etc
111
What are eicosanoids?
Include prostaglandins and thromboxanes
They are local signalling molecules, and are involved in vasodilation and inflammation.
they are made from fatty acids
112
What are the three series of prostaglandins?
Series 1: from DGLA - anticlotting, removes excess water from body, vasodilation - anti-inflammatory
Series 2: from AA - platelet aggregation, sodium and water retention - pro-inflammatory
Series 3: prevents the release of AA from cell membranes - anti-inflammatory
113
Why does the omega-3 to 6 ratio matter?
They compete for the same enzymes - delta-d desaturase, elongase etc
114
What are EFA testing for?
omega-3 index: CV risk
omega-6:3 index: chronic illness
AA:EPA ratio: inflammation
115
What are the functions of cholesterol?
Steroid hormones, vit D production from sunlight, bile salts, membrane integrity
116
What do each of the different lipoproteins do?
LDL - takes cholesterol from liver to cells
VLDL - takes triglycerides to cells
HDL - takes cholesterol from cells to liver
117
What is lipoprotein a?
a blood clotting agent, associated with increased risk of CVD
118
What are some cardiovascular markers?
lipoprotein a, lipoprotein PLA2, fibrinogen, CRP, lipid peroxidases
119
What is inositol?
a phospholipid that improves insulin sensitivity
120
What are the beneficial effects of phosphatidylserine and phosphatidylcholine?
Neuroprotective, helps with stress, memory
121
What is the amount of EPA that is converted to ALA?
1-20%
122
What are the food sources of stearidonic acid?
Current seeds
