Unit 7 Flashcards
What is a balanced diet?
One which provides the right amount of each nutrient and energy for a person’s need
The 7 types of nutrients
Carbohydrates
Lipids (fats and oils)
Fibre
Minerals
Vitamins
Water
Proteins
Carbohydrates: examples and use in body
Examples:
- Pasta, rice, bread, potatoes
Use in body:
- Provides energy
Lipids (fats and oils): examples and use in body
Examples:
- Butters, oils
Use in body:
- Insulation, provides energy, protection of vital organs
Proteins: examples and use in body
Examples:
- Beans, meat, fish
Use in body:
- Growth and repair
Vitamins: Vitamins C examples and use in body
Examples:
- Oranges, lemons
Use in body
- Tissue repair, resistance to diease
Vitamims: vitamin D examples and use in body
Examples:
- Fish oil, milk, butter,
Use in body
- Strengthens bones and teeth
Minerals: Calcium examples and use in body
Examples:
- Milk, fish, vegies
Use in body:
- Strenthens bone and teeth
Minerals: Iron examples and use in body
Examples:
- Meat, eggs, cocoa
Use in body:
- Used in formation of heamaglobin in red blood cells for transport of oxygen
Fibre: examples and use in body
Examples:
- Wheats, oats, kiwi
Use in body:
- Helps food move through the gut
Water: examples and use in body
Examples:
- Water, watermelon
Use in body:
- Major component of cytoplasm and blood
Factors that influence the nutrients a person needs
- Age
- Activity levels
- Gender
Why are diseases caused?
Lack of vitamin
Causes of scurvy
Lack of vitamin C
Symptoms of scurvy
Bleeding gums
Poor wound healing
Pain, especially in the legs
Cause of rickets
Lack of vitamin D and calcium
Symptoms of Rickets
Weak or brittle bones
Bone deformation
Bone pain
Ingestion
The taking of food or drink into the body
Digestion
The breaking down of large insoluble food molecules into small, soluble molecules
Absorption
When the small soluble molecules pass into the blood
Assimiliation
Is the use/uptake of food molecules by our body cells
Egestion
The removal of undigested food from the body as faeces
What is physical digestion
The breakdown of food into smaller pieces without chemical change to the food molecules
What does physical digestion do
It increases the surface area of food for the action of enzymes in chemical digestion
What is chemical digestion
Breaking down of large insoluble food molecules into small soluble food molecules
Digestive enzymes: Starch
Starch -> amylase enzyme -> breaks down into simple reducing sugars
Digestive enzymes: proteins
Proteins -> protease enzymes -> amino acids
Digestive enzymes: fats and oils
Fats and oils -> lipase enzymes -> glycerol and fatty acids
Amylase enzymes: made and where it acts
Made:
Salivary glands
Pancreas
Small intestine
Acts:
Mouth
Small intestine
Protease enzymes: made and where it acts
Made:
Stomach
Pancreas
Small intestine
Act:
Stomach
Small intestine
Lipase enzymes: made and where it acts
Made:
Pancreas
Small intestine
Acts:
Small intestine
Mechanical digestion
Breakdown of food into smaller pieces without the food molecules undergoing a chemical change
Where does mechanical digestion happens
First occurs in the mouth by the teeth
- The teeth breaks food into smaller pieces for a bigger surface for enzymes to act
The 4 types pf teeth
Molars
Pre molars
Canines
Incisors
Structure of teeth (6)
Enamel
Dentine
Gum
Pulp
Cement
Bone
Enamel
Hard outer layer
Cement
Bone-like tissue, holds tooth in place
Bone
What embeds tooth
Dentine
Softer material that forms the bulk of tooth
Gum
Soft tissue that surrounds and protects the tooth and bone
Pulp
Soft tissue that contains nerves and blood vessels
Incisors
Bitting and cutting
Molars
Crushing and grinding
Canines
Gripping and tearing
Pre molars
Tearing and crushing
Unsoluble molecules
Proteins, starch, fats -> polymers that need to break down
Soluble molecules
Water and oxygen
Digestion of starch in digestive system
-Starch breaks down into maltose by amylase
-Maltase breaks down maltose to glucose on the epithelium lining the small intestine
Pepsin
Enzyme in the stomach
- Best in acidic conditions
Trypsin
Enzyme in the small intestine
-Best in alkaline conditions
Bile
- Released in the Duodenum
- Bile is a mixture of alkaline chemicals - the optimum pH for enzymes that work in the small intestine
- It emulsifies fats - bigger surface area for lipase
- It is very alkaline
Where is most water absorbed?
From the small intestine but that some is also absorbed in the colon
Adaptations of small intestine
- most absorption takes place in the small intestine
- Large surface area
- lots of vili and microvili -> contain mitochondria for active transport of glucose
- Blood capillary network to transport nutrients
(Shorter diffusion distance transport of nutrients to every cell for respiration)
Lacteals
1) fats move from the small intestine to the lacteals in the vili
2) these contain lymph to transport fats away from the small intestine
3) Lacteals merge into larger vessels, before the lymph empties into the blood
Significance of microvili and vili
Microvili and vili increase surface area -> therefore faster absorption of nutrients in small intestine
