Nutrients Flashcards
What are the six main types of nutrients?
Water, Carbohydrates, Lipids, Proteins, Minerals, Vitamins
What are essential nutrients?
Nutrients that are inadequately synthesized by body cells and must be included in the diet
How are carbohydrates primarily categorized?
Plant products like starch, which are digested to monosaccharides
What is glucose used for in the body?
Production of ATP
What enzyme is responsible for the digestion of triglycerides?
Lipase
List the functions of different lipids.
- Fatty acid: Synthesis of triglycerides & phospholipids, Catabolised to generate ATP
- Triglycerides: Protection from injury, insulation, energy storage
- Phospholipids: Component of cell membranes
- Steroids: Precursor to bile salts, vitamin D & steroid hormones
- Prostaglandins: Local hormones that intensify effects of histamine & induce pain
What are lipoproteins and their function?
Molecules that transport lipids in the blood, allowing hydrophobic lipids to circulate
What is the primary function of HDL?
Remove excess cholesterol from peripheral tissues and transport it to the liver
What dietary factors can raise HDL levels?
- Exercise
- Smoking cessation
- Maintaining normal weight
- Increasing omega-3 fish oil intake
- Increasing dietary fiber
- Reducing trans fats
What percentage of necessary cholesterol is obtained from diet?
15%
What is the role of saturated fats in cholesterol levels?
Stimulate the liver to make more cholesterol and inhibit its excretion in bile
True or False: Excessive LDL levels can lead to heart disease.
True
What are the two-step processes for protein digestion?
- Protein → peptide
- Peptide → amino acid
List the types of proteins and their functions.
- Structural proteins: Provide strength (e.g. collagen)
- Hormones: e.g. insulin
- Contractile proteins: Allow muscle contraction
- Antibodies: Defense against foreign cells
- Hemoglobin: Transports oxygen
- Enzymes: Speed up chemical reactions
- Neurotransmitters
What are vitamins and their general role in the body?
Organic nutrients needed in tiny amounts; they do not provide energy but act mainly as co-enzymes
What distinguishes fat-soluble vitamins from water-soluble vitamins?
Fat-soluble vitamins are stored in the body, while water-soluble vitamins are excreted in urine
Which vitamins are antioxidants?
- Vitamin A (beta carotene)
- Vitamin C
- Vitamin E
What is the function and source of Vitamin D?
Essential for absorption of calcium and phosphorus; sources include fish liver oils, egg yolk, and fortified milk
What are common minerals and their functions?
- Calcium: Formation of bones & teeth, blood clotting
- Iron: Required for enzyme reactions, RBC formation
- Magnesium: Normal muscle & nervous tissue function
- Sodium: Affects distribution of water
- Potassium: Conduction of action potentials
- Iodine: Synthesis of thyroid hormones
Fill in the blank: Minerals are ______ substances needed in small amounts.
[inorganic]
What can excessive mineral intake lead to?
Harmful effects, such as high blood pressure from excessive sodium intake
Proteins are absorbed from the digestive tract as?
Amino acids
Steroids are synthesised from?
Cholesterol
Folic acid is required for?
Synthesis of RNA & DNA
