2e-Nutrition Flashcards
What are the essential nutrients required in a balanced diet?A:
A balanced diet includes:
Carbohydrates: Provide energy.
Proteins: Build and repair tissues.
Lipids (Fats and Oils): Store energy and insulate the body.
Vitamins: Essential for metabolic processes (e.g., Vitamin C for healthy skin, Vitamin D for strong bones).
Minerals: Support body functions (e.g., Calcium for bones, Iron for blood).
Water: Maintains hydration and supports bodily functions.
Fibre: Aids digestion by helping food move through the gut.
How do energy requirements vary with activity levels, age, and pregnancy?
Activity levels: More active individuals need more energy.
Age: Teenagers and growing children need more energy than adults.
Pregnancy: Pregnant women need more energy and nutrients to support the developing fetus
What is the structure and function of the human alimentary canal?
A: The alimentary canal is a tube through which food passes during digestion:
What is the structure and function of the human alimentary canal? Mouth
Mouth: Ingestion and mechanical digestion; saliva contains amylase.
What is the structure and function of the human alimentary canal? Oesophagus
Oesophagus: Transports food to the stomach using peristalsis.
What is the structure and function of the human alimentary canal? Stomach
Stomach: Produces hydrochloric acid to kill bacteria and pepsin to digest proteins.
What is the structure and function of the human alimentary canal? Small intestine
Small Intestine: Duodenum (digestion continues), Ileum (absorption of nutrients through villi).
What is the structure and function of the human alimentary canal? Large intestine
Large Intestine: Absorbs water and forms feces.
What is the structure and function of the human alimentary canal? Rectum
Rectum: Stores feces before excretion.
What is the structure and function of the human alimentary canal? Anus
Anus: Releases feces from the body.
What is peristalsis and why is it important?
A: Peristalsis is the wave-like contraction of muscles that moves food along the digestive tract. It ensures food is mixed with digestive enzymes and continues to move toward absorption and excretion.
What is the role of digestive enzymes?
A: Enzymes break down large molecules into smaller, absorbable ones:
Amylase: Starch → Glucose
Protease: Proteins → Amino acids
Lipase: Lipids → Fatty acids + Glycerol
What is the function of bile?
A: Bile is produced by the liver, stored in the gall bladder, and released into the small intestine. It neutralizes stomach acid and emulsifies lipids, increasing their surface area for lipase action.
Investigating Digestion
Effect of Amylase on Starch
Method: Add starch solution and amylase enzyme to a test tube. Incubate at different temperatures. Test with iodine solution at intervals.
Positive Result: Iodine remains orange-brown, indicating starch has been digested.
Negative Result: Iodine turns blue-black, indicating starch is still present.
Investigating Digestion
Testing for Glucose (End Product of Starch Digestion)
Testing for Glucose (End Product of Starch Digestion)
Method: Heat Benedict’s solution with a sample from the experiment.
Positive Result: Color change from blue to brick-red indicates glucose is present.
Negative Result: Solution remains blue, indicating no glucose.
order of digestion:
Ingestion → Digestion → Absorption → Assimilation → Egestion
