CHAPTER 6-10 Flashcards
1
Q
What are amino acids?
A
Building blocks of proteins.
2
Q
What are essential amino acids?
A
Amino acids the body cannot synthesize in sufficient amounts—must come from the diet.
3
Q
What are conditionally essential amino acids?
A
Usually non-essential but become essential under certain conditions (e.g., illness, stress).
4
Q
What is transamination?
A
Process by which the body synthesizes nonessential amino acids.
5
Q
What determines a protein’s function?
A
Its shape.
6
Q
What are the two key processes in protein synthesis?
A
Transcription and translation.
7
Q
Name 5 functions of proteins in the body.
A
Structure, enzymes, transport, immune system, hormones.
8
Q
How do proteins help in fluid and acid-base balance?
A
Through protein pumps in cells and proteins in the blood.
9
Q
How is protein used for energy?
A
Amino acids are deaminated → used to make glucose (gluconeogenesis), energy, or fat.
10
Q
When does the body use protein for energy?
A
Starvation, low carb intake, or excess protein.
11
Q
What is the RDA for protein?
A
0.8 g/kg body weight/day.
12
Q
What percent of daily calories should come from protein (AMDR)?
A
10–35%.
13
Q
Who needs more protein?
A
Infants, children, pregnant/lactating people, athletes, people under stress or illness.
14
Q
What is nitrogen balance?
A
A method of determining protein needs (positive = growth, negative = loss).
15
Q
What is Kwashiorkor?
A
Protein deficiency with adequate calories → bloated belly due to liver fat/fluid.
16
Q
What is Marasmus?
A
Energy deficiency → severe wasting and possible ketosis.
17
Q
Risks of too much protein?
A
Kidney strain, dehydration, potential CVD/cancer, digestive issues, nutrient imbalance.
18
Q
What is PKU?
A
Inherited condition where phenylalanine can’t be metabolized → avoid aspartame.
19
Q
What causes food allergies?
A
Immune response to undigested dietary proteins.
20
Q
Common food allergens?
A
Milk, eggs, nuts, soy, wheat, fish, shellfish, peanuts.
21
Q
What is anaphylaxis?
A
Severe, life-threatening allergic reaction.
22
Q
What does the Canada Food Guide recommend?
A
Choose plant-based protein more often.
23
Q
Plant protein sources?
A
Legumes, nuts, seeds, soy, grains.
24
Q
Health benefits of plant proteins?
A
Lower risk of CVD, type 2 diabetes, high BP.
25
Concerns with plant protein?
Lower digestibility, incomplete proteins, lower B12, iron, omega-3s, calcium.
26
What is a complete protein?
Contains all essential amino acids in right proportions.
27
What is PDCAAS?
Protein Digestibility-Corrected Amino Acid Score — measures protein quality.
27
What is an incomplete protein?
Missing one or more essential amino acids.
28
PDCAAS examples (high vs low):
High: Dairy, eggs, soy (1.0)
Low: Lentils (0.52), peanuts (0.52), wheat (0.41)
29
Semi-vegetarian?
Avoids certain meats.
30
Pescetarian?
Eats fish but no other meats.
31
Lacto-ovo vegetarian?
Eats dairy and eggs, no meat.
32
Lacto vegetarian?
Eats dairy, no eggs or meat.
33
Vegan?
Avoids all animal products.
34
What is protein complementation?
Combining incomplete proteins to make a complete one.
35
What BMI range is classified as overweight?
25–29 kg/m²
36
What BMI is classified as obese?
Over 30 kg/m²
37
Name two cardiovascular risks associated with obesity.
Increased blood pressure and elevated LDL cholesterol
38
What is energy balance?
When energy intake equals energy expenditure
39
What tool is used to determine energy content in food?
Bomb calorimeter
40
Calculate the kcal in 2g fat, 4g carb, and 6g protein.
58 kcal (18 from fat + 16 from carbs + 24 from protein)
41
What are the 3 components of TEE?
BMR, Physical Activity, Thermic Effect of Food (TEF)
42
What factors affect BMR?
Lean mass, age, height, gender, thyroid hormone, fasting, pregnancy
43
What is the respiratory quotient (RQ) of carbs?
1.0
44
What method uses oxygen consumption and CO₂ production to estimate energy expenditure?
Indirect calorimetry
45
What is the formula for total energy expenditure?
TEE = BMR × Activity Factor
46
What method measures body fat using electrical current?
Bioelectrical Impedance Analysis (BIA)
47
What is the limitation of BMI?
Doesn’t distinguish fat from muscle; not suitable for children, elderly, athletes, pregnant women
48
Apple-shaped fat pattern is associated with what?
Higher risk of chronic disease
49
What body composition method uses X-rays?
Dual-Energy X-ray Absorptiometry (DEXA)
50
What hormone reduces food intake and increases energy use?
Leptin
51
What gene is responsible for leptin production?
ob gene
52
What does ghrelin do?
Stimulates hunger and decreases energy expenditure
53
What is the set-point theory?
Body maintains weight within a set range after growth
54
What is adaptive thermogenesis?
Change in energy use due to environmental or dietary changes
55
What is the thrifty gene hypothesis?
Suggests some people genetically conserve energy, making weight gain easier
56
What is a healthy rate of weight loss?
0.25–1 kg per week
57
Name 3 aspects of a positive weight loss strategy.
Physical activity, gradual weight loss, behavior change
58
When is surgery considered for obesity?
Class II or III obesity with unsuccessful other treatments
59
What medication mimics GLP-1 and helps with weight loss?
Ozempic (Semaglutide)
60
What does CBT stand for in weight management?
Cognitive Behaviour Therapy
61
Why are fad diets popular?
Promise fast results, use scientific language, word-of-mouth promotion
62
What are risks of fad diets?
Nutrient deficiencies, metabolic slowdown, disordered eating
63
What is a key difference between a healthy diet and a fad diet?
Healthy diets are sustainable and nutritionally adequate; fad diets are restrictive and often unbalanced
64
Does intermittent fasting lead to greater weight loss than regular eating?
No, studies show no significant difference
65
What are coenzymes?
Non-protein compounds that bind to enzymes and help them function, often derived from B vitamins.
66
What is bioavailability?
The amount of a nutrient absorbed and utilized by the body.
67
What influences vitamin bioavailability?
Diet composition, body needs, and vitamin form (e.g., provitamin vs. active).
68
Difference between fortification and enrichment?
Fortification adds nutrients not originally present; enrichment restores lost nutrients after processing.
69
Who might benefit from vitamin supplements?
Vegans, pregnant women, older adults, infants, people on restricted diets, and those with dark skin or who cover up.
70
Thiamin coenzyme and function?
TPP; involved in decarboxylation, acetyl-CoA formation, citric acid cycle, and nerve function.
71
Thiamin deficiency disease?
Beriberi – causes muscle wasting, nerve and cardiovascular issues.
72
Food sources of thiamin?
Pork, whole grains, legumes, organ meats, enriched cereals.
73
Riboflavin coenzyme and functions?
FAD/FMN; energy production, electron transport, vitamin activation.
74
Riboflavin deficiency symptoms?
Ariboflavinosis – inflammation, skin issues, cracked lips/mouth.
75
Riboflavin sources?
Dairy, leafy greens, meat, whole grains. Destroyed by light and heat.
76
Niacin coenzymes?
NAD and NADP; involved in ATP production, fatty acid, and cholesterol synthesis.
77
Niacin deficiency?
Pellagra – 3 D's: dermatitis, diarrhea, dementia.
78
Niacin sources?
Animal products, enriched grains, legumes, mushrooms.
79
What amino acid can synthesize niacin?
Tryptophan.
80
Vitamin B6 coenzyme and main functions?
PLP; amino acid metabolism, neurotransmitter and hemoglobin synthesis, tryptophan to niacin conversion.
81
B6 deficiency symptoms?
Microcytic anemia, insomnia, weakness, immune dysfunction, nervous issues.
82
B6 food sources?
Meat, fish, poultry, enriched cereals, some fruits and veggies.
83
Folate’s coenzyme and function?
THF; DNA/RNA synthesis, new cell production, amino acid metabolism.
84
Folate deficiency issues?
Macrocytic anemia, neural tube defects, increased heart disease and cancer risk.
85
Folate sources?
Leafy greens, legumes, oranges, enriched grains, organ meats.
86
When was folate fortification implemented in Canada?
1998 – flour, pasta, and cornmeal.
87
B12 coenzymes?
Methylcobalamin and adenosylcobalamin.
88
B12 main functions?
DNA synthesis, myelin formation, odd-chain fatty acid metabolism, RBC production, nerve function.
89
What can mask B12 deficiency?
High supplemental folic acid.
90
B12 absorption process?
Requires stomach acid and intrinsic factor for absorption in the small intestine.
91
B12 deficiency consequences?
Megaloblastic anemia, nerve damage, decreased immunity.
92
At-risk groups for B12 deficiency?
Elderly, vegans, people with atrophic gastritis or pernicious anemia.
93
B12 sources?
Animal foods: meat, eggs, milk, fish, fortified products.
94
Biotin function?
Coenzyme for adding COOH groups in metabolism (citric acid cycle, glucose synthesis).
95
Pantothenic acid function?
Part of coenzyme A; important for fatty acid and cholesterol synthesis.
96
Vitamin C functions?
Collagen synthesis, antioxidant, immune support, aids iron absorption, coenzyme for neurotransmitter synthesis.
97
Vitamin C deficiency disease?
Scurvy – poor wound healing, bleeding gums, joint pain.
98
Vitamin C sources?
Fresh fruits and vegetables. Easily destroyed by heat and light.
99
How does vitamin C act as an antioxidant?
Donates electrons to neutralize free radicals, preventing cellular damage.
100
What are free radicals?
Reactive oxygen species with unpaired electrons, damage proteins, lipids, DNA.
101
Choline functions?
Acetylcholine synthesis, phospholipid formation, homocysteine metabolism.
102
Choline deficiency effect?
Fat accumulation in liver.
103
Choline sources?
Milk, liver, eggs, legumes, peanuts.
104
What do fat-soluble vitamins require for absorption?
They require bile and dietary fat for absorption.
104
What are the fat-soluble vitamins?
Vitamin A, Vitamin D, Vitamin E, Vitamin K
105
How are fat-soluble vitamins transported in the body?
They are transported through the lymphatic system in chylomicrons.
106
What is the risk associated with high intake of fat-soluble vitamins?
The risk of toxicity is higher due to their storage in body fat and limited excretion.
107
How are fat-soluble vitamins stored in the body?
They are stored in body fat.
108
What are the forms of Vitamin A?
Retinoids (retinol, retinal, retinoic acid) and carotenoids (alpha- and beta-carotene).
109
What is the function of Vitamin A in the body?
It is involved in vision (especially night vision), gene expression, and cell differentiation and growth.
110
What are the food sources of Vitamin A?
Animal products (liver, fish, fortified milk) and plant sources (carrots, leafy greens, sweet potatoes, apricots, cantaloupe)
111
What is Vitamin A deficiency associated with?
Reduced immune function, impaired reproduction, poor growth, dry skin, and organ system defects.
112
What are the consequences of Vitamin A toxicity?
Headache, vomiting, hair loss, liver damage, skin changes, bone pain, fractures, and birth defects.
113
What are the functions of Vitamin D in the body?
It helps maintain calcium and phosphorus levels in the blood, supports bone health, regulates immune function, and prevents cancer.
114
What are the food sources of Vitamin D?
Egg yolk, liver, fish oils, tuna, salmon, fortified milk, and sunlight.
114
What is the consequence of Vitamin D deficiency in children?
Rickets, characterized by abnormal growth, misshaped bones, and soft bones.
115
What are the functions of Vitamin E?
Vitamin E acts as an antioxidant, protecting cell membranes, nerve tissue, red blood cells, immune cells, and lung cells.
116
What are the food sources of Vitamin E?
Vegetable oils, leafy greens, seeds, nuts, and peanuts.
116
What is the consequence of Vitamin D deficiency in adults?
Osteomalacia, resulting in weak bones, bone pain, and muscle aches.
117
What are the risks associated with Vitamin D toxicity?
Calcium deposits in blood vessels and kidneys, cardiovascular damage, and potentially death.
118
What is Vitamin K essential for?
Blood coagulation, proper bone metabolism, and maintaining vessel health.
118
What is the consequence of Vitamin E deficiency?
Broken red blood cells, nerve damage, and at-risk populations include those with fat malabsorption or genetic problems.
119
What are the food sources of Vitamin K?
Vegetable oils, leafy greens, and synthesis by intestinal bacteria.
120
What is the function of phytochemicals in functional foods?
Phytochemicals are health-promoting substances found in plant foods, such as carotenoids, flavonoids, and phytoestrogens, which provide benefits beyond basic nutrition.
121
What are examples of phytochemicals?
Carotenoids (e.g., beta-carotene), flavonoids (e.g., blueberries), indoles and alliums (e.g., garlic, onions), and phytoestrogens (e.g., soy, flaxseed).
122
How can you increase phytochemical intake?
Eat more fruits and vegetables, make half your grains whole, choose sources of plant protein, and be cautious with phytochemical supplements.
122
What percentage of the human body is water?
50–70%, depending on tissue type, age, and gender.
123
What are the two major fluid compartments in the body?
Intracellular (inside cells) and extracellular (outside cells—interstitial fluid, lymph, plasma).
124
What are the key ions in intracellular vs. extracellular fluid?
Intracellular: high K+, proteins.
Extracellular: high Na+ and Cl-.
125
What are 5 major functions of body fluids?
Transport, regulate temperature, maintain blood volume/pressure, protect tissues, lubricate joints.
126
How does the body gain fluids?
Beverages, food, and metabolic water (~10–14% of daily needs).
127
What are the major routes of fluid loss?
Urine, sweat, lungs, feces; increased with heat, exercise, illness, pregnancy, breastfeeding, diuretics.
128
What is the AI for water intake?
Men: 3.7 L/day, Women: 2.7 L/day (includes fluids from food).
129
What hormone helps the body retain water?
Antidiuretic Hormone (ADH).
130
What system regulates blood pressure through fluid balance?
Renin-Angiotensin-Aldosterone system.
130
What are signs of dehydration based on body weight loss?
1–2%: thirst, discomfort; 3–5%: nausea, confusion; >8%: delirium, death.
131
What are 3 key functions of sodium?
Nerve transmission, muscle contraction, fluid balance.
132
What is the AI and UL for sodium?
AI: 1500 mg/day; UL/CDRR: 2300 mg/day.
133
What is hyponatremia?
Abnormally low blood sodium, often due to excessive water intake with sodium loss (e.g., athletes).
134
How does high sodium intake affect health?
Increases risk of hypertension, heart disease, kidney damage.
134
What proportion of Canadians are salt-sensitive?
About 1/3 of the population.
135
What is essential hypertension?
High blood pressure with no obvious cause.
136
What is secondary hypertension?
High blood pressure due to another condition (e.g., kidney disease).
136
What diet is recommended to reduce blood pressure?
DASH diet: more fruits, vegetables, low-fat dairy; less sodium, sugar, red meat.
137
How does potassium affect blood pressure?
High potassium intake helps lower blood pressure.
137
What are 3 main functions of potassium?
Nerve impulses, muscle contraction, fluid balance.
138
What is the RDA for potassium?
4700 mg/day.
139
What are symptoms of potassium deficiency?
Irregular heartbeat, fatigue, muscle cramps.
139
What are good food sources of potassium?
Fruits, vegetables, legumes, whole grains, milk, meat.
140
What can cause potassium toxicity?
Supplements or kidney dysfunction.
140
What are 3 functions of chloride?
Fluid balance, component of stomach acid (HCl), immune defense.
141
What are food sources of chloride?
Table salt, fruits, vegetables, processed foods.
141
Is chloride deficiency common?
No, it's rare. Can occur with vomiting, severe dehydration, eating disorders.
142
What can very high chloride intake cause?
Can contribute to hypertension.
