48 Topics Flashcards
What is glucose used for?
• Primary energy source for cells
• Stored as glycogen in liver & muscles
• Converted to fat when excess
• Essential for brain and RBCs
List the carbohydrate continuum from monosaccharides to polysaccharides and provide examples.
• Monosaccharides: Glucose, fructose, galactose
• Disaccharides: Sucrose, lactose, maltose
• Oligosaccharides: Raffinose, stachyose
• Polysaccharides: Starch, glycogen, fiber
Describe major carbohydrate metabolic processes: glycolysis, gluconeogenesis, glycogenesis, and glycogenolysis.
• Glycolysis: Glucose → ATP + pyruvate
• Gluconeogenesis: Non-carbs → glucose
• Glycogenesis: Glucose → glycogen
• Glycogenolysis: Glycogen → glucose
What is cholesterol used for?
• Component of cell membranes
• Precursor for steroid hormones
• Essential for bile acid production
• Used in vitamin D synthesis
What are the three classes of lipids, and can you provide examples of each?
• Triglycerides: Fat storage - Butter, oils, adipose tissue
• Phospholipids: Cell membranes - Lecithin in eggs, soy
• Sterols: Cholesterol - Animal products
What are good sources of proteins and amino acids?
• Animal sources: Meat, eggs, dairy
• Plant sources: Beans, lentils, soy
What is the difference between complete and incomplete proteins?
• Complete proteins: Contain all 9 essential amino acids - Meat, dairy, eggs
• Incomplete proteins: Lack one or more essential amino acids - Grains, legumes
List the 8 essential amino acids.
- Leucine
- Isoleucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
What is the role of amino acids in metabolism, and how are nitrogenous groups processed?
• Amino acids build proteins and enzymes
• Excess nitrogen is removed as urea in urine
What is the recommended daily protein intake?
• 0.8 g/kg body weight for average adults
• 1.2-2.0 g/kg for athletes
What is the function of vitamins, and what is the difference between fat-soluble and water-soluble vitamins?
• Vitamins regulate metabolism & immune function
• Fat-soluble: A, D, E, K - stored in fat
• Water-soluble: B-complex, C - excreted in urine
What happens if you consume an excess amount of vitamin D?
• Hypercalcemia
• Kidney damage
• Nausea, vomiting, and weakness
What are the recommended daily intake levels for minerals like phosphorus and iron?
• Phosphorus: 700 mg/day
• Iron: Men: 8 mg/day, Women (premenopausal): 18 mg/day
How is calcium regulated in the body, and what is its role?
• Regulated by vitamin D & parathyroid hormone (PTH)
Functions:
• Bone formation & maintenance
• Muscle contraction
• Nerve transmission
What are the sources of water intake in the diet?
• Beverages: water, juice, milk
• Food: fruits, vegetables, soups
• Metabolic water: produced during metabolism
What are the sources of fluid loss in the body?
• Urine
• Sweat
• Breathing
• Feces
What is the primary function of water in the body?
• Regulates body temperature
• Transports nutrients & waste
• Lubricates joints
What are the major electrolytes in the body, and what are their functions?
• Sodium: Regulates fluid balance & nerve signals
• Potassium: Muscle contraction & heart function
• Calcium: Bone strength & muscle function
Where are different nutrients absorbed in the gastrointestinal (GI) tract?
• Carbohydrates: Small intestine
• Proteins: Small intestine
• Fats: Small intestine
• Alcohol: Stomach & small intestine
What is the role of the pancreas in digestion?
• Produces digestive enzymes (amylase, lipase, protease)
• Secretes insulin & glucagon for blood sugar control
What is the function of bile in digestion?
• Emulsifies fats for absorption
• Produced by liver, stored in gallbladder
What are the major digestive hormones, and what do they regulate?
• Gastrin: Stimulates stomach acid
• Insulin: Lowers blood sugar
• Glucagon: Raises blood sugar
• Cholecystokinin (CCK): Stimulates bile release
What is GERD (Gastroesophageal Reflux Disease), and what causes it?
• Stomach acid flows back into the esophagus
Causes:
• Weak lower esophageal sphincter
• Overeating, acidic/spicy foods, caffeine
What is an enzyme, and what is its function in metabolism?
• Enzymes are proteins that speed up chemical reactions
• Lower activation energy of reactions
• Highly specific to substrates
What are the major types of chemical reactions in metabolism (anabolic vs. catabolic reactions)?
• Anabolic reactions: Build molecules, require energy
• Catabolic reactions: Break down molecules, release energy
What are the primary buffering systems in the body?
• Bicarbonate buffer system
• Phosphate buffer system
• Protein buffer system
How are fluids transported in the body (diffusion, osmosis, facilitated diffusion, active transport, endocytosis)?
• Diffusion: Molecules move from high to low concentration
• Osmosis: Water moves across a membrane
• Facilitated diffusion: Needs carrier proteins, no energy required
• Active transport: Requires ATP to move substances
• Endocytosis: Cell engulfs molecules into vesicles
What are the differences between Type 1 and Type 2 diabetes?
• Type 1 diabetes: Autoimmune, no insulin production
• Type 2 diabetes: Insulin resistance, linked to obesity
How does insulin regulate blood sugar?
• Promotes glucose uptake by cells
• Stimulates glycogen synthesis in liver & muscles
• Inhibits fat breakdown
How does exercise help regulate blood sugar?
• Increases insulin sensitivity
• Promotes glucose uptake by muscles
• Reduces risk of Type 2 diabetes
What is glycemic index (GI), and how does it affect blood sugar?
• Measures how fast a food raises blood sugar
• High GI foods → Rapid spike
• Low GI foods → Slow release
What are the symptoms of dehydration?
• Dry mouth, fatigue, dizziness
• Dark urine, reduced urination
• Reduced cognitive and physical performance
How much water should an average adult consume daily?
• About 2-3 liters (8-12 cups) depending on activity level and climate
What are the symptoms of dehydration?
• Dry mouth, fatigue, dizziness (口干、疲劳、头晕)
• Dark urine, reduced urination (尿液颜色深，排尿减少)
• Reduced cognitive and physical performance (认知和运动能力下降)
How much water should an average adult consume daily?
• Men: ~3.7L/day (男性：约3.7升/天)
• Women: ~2.7L/day (女性：约2.7升/天)
How does sodium intake affect blood pressure?
• High sodium → increased blood volume → higher blood pressure (高钠摄入 → 增加血容量 → 升高血压)
• Increased risk of hypertension (增加高血压风险)
What is the ideal macronutrient ratio for athletes?
• Carbs: 50-60% (碳水化合物：50-60%)
• Protein: 15-20% (蛋白质：15-20%)
• Fat: 20-30% (脂肪：20-30%)
What is the best timing for post-exercise nutrition?
• Within 30-60 minutes post-workout (运动后30-60分钟内)
• Carbohydrates replenish glycogen (碳水化合物补充糖原)
• Protein supports muscle repair (蛋白质促进肌肉修复)
How does protein intake support muscle recovery?
• Supports muscle protein synthesis (支持肌肉蛋白合成)
• Reduces muscle breakdown (减少肌肉分解)
• Enhances repair & adaptation to exercise (促进恢复并适应运动)
What are free radicals, and how do they impact health?
• Free radicals are unstable molecules that cause cell damage (自由基是可破坏细胞的活性分子)
• Generated during metabolism, pollution, UV exposure (在代谢、污染、紫外线照射时产生)
• Contribute to aging, cancer, and chronic diseases (促进衰老、癌症和慢性病)
What are common dietary antioxidants?
• Vitamin C (citrus fruits, bell peppers) (维生素C：柑橘类、甜椒)
• Vitamin E (nuts, seeds, spinach) (维生素E：坚果、种子、菠菜)
• Polyphenols (green tea, berries, dark chocolate) (多酚类：绿茶、浆果、黑巧克力)
How does oxidative stress contribute to aging and disease?
• Damages DNA and cellular structures (损害DNA和细胞结构)
• Leads to inflammation and cell death (导致炎症和细胞死亡)
• Plays a role in neurodegenerative diseases (Alzheimer’s, Parkinson’s) (与神经退行性疾病相关，如阿尔茨海默病、帕金森病)
What are key factors that promote longevity?
• Balanced diet rich in antioxidants and anti-inflammatory foods (富含抗氧化和抗炎食物的均衡饮食)
• Regular physical activity (规律运动)
• Caloric restriction without malnutrition (适度限制热量摄入但不导致营养不良)
• Strong social connections (良好社交关系)
What role do telomeres play in aging?
• Telomeres protect chromosomes from damage (端粒保护染色体免受损伤)
• Shortening of telomeres is associated with aging (端粒缩短与衰老相关)
• Healthy lifestyle choices may slow telomere shortening (健康的生活方式可减缓端粒缩短)
What is Irritable Bowel Syndrome (IBS), and what are its symptoms?
• IBS is a chronic digestive disorder affecting gut motility (肠易激综合征是一种影响肠道蠕动的慢性消化疾病)
Symptoms:
• Abdominal pain & cramping (腹痛和痉挛)
• Bloating & gas (腹胀和胀气)
• Diarrhea or constipation (腹泻或便秘)
How does fiber impact digestion and gut health?
• Insoluble fiber (whole grains, vegetables): Adds bulk, prevents constipation (不溶性纤维：增加粪便体积，防止便秘)
• Soluble fiber (oats, beans, fruits): Slows digestion, controls blood sugar (可溶性纤维：减缓消化，调节血糖)
• Feeds beneficial gut bacteria (prebiotic effect) (促进益生菌生长，起到益生元作用)
What causes acid reflux and GERD?
• Weak lower esophageal sphincter (LES) (下食管括约肌无力)
• Overeating, acidic/spicy foods, caffeine, alcohol (暴饮暴食、酸性/辛辣食物、咖啡因、酒精)
• Obesity and smoking increase risk (肥胖和吸烟增加风险)
What factors contribute to osteoporosis?
• Calcium and vitamin D deficiency (缺乏钙和维生素D)
• Lack of weight-bearing exercise (缺乏负重运动)
• Hormonal imbalances (low estrogen/testosterone) (激素水平失衡，如雌激素/睾酮减少)
What are good dietary sources of calcium?
• Dairy (milk, yogurt, cheese) (奶制品：牛奶、酸奶、奶酪)
• Leafy greens (kale, spinach, bok choy) (深色绿叶蔬菜：甘蓝、菠菜、白菜)
• Sardines and salmon (with bones) (沙丁鱼和带骨三文鱼)
What is the role of vitamin D in bone health?
• Enhances calcium absorption in the intestines (促进肠道对钙的吸收)
• Regulates bone mineralization (调节骨矿化)
• Prevents osteoporosis (预防骨质疏松)
