3 DIET + DIGESTION Flashcards
One function that carbohydrates, proteins and lipids all have in common
Fuel for respiration
Function of carbohydrates
Fuel for respiration
Function of proteins
Growth and repair of cells and tissues - fuel for respiration
Function of proteins
Growth and repair of cells and tissues - fuel for respiration
Function of lipids
Store of energy, fuel for respiration - thermal and electrical insulation
3 food sources of carbohydrates
Bread, potatoes, rice
3 food sources of proteins
meat, eggs, quinoa
3 food sources of lipids
Butter, avacados, oil
Function of iron
Forms part of haemoglobin for which binds to oxygen
Function of calcium
Needed to form bones and teeth
3 food sources for iron
spinach, liver and red meat
3 food sources for calcium
milk + dairy, fish and fresh vegetables
3 food sources for calcium
milk + dairy, fish and fresh vegetables
Deficiency for iron
Anaemia
Deficiency for calcium
Rickets
Use of Vitamin A
Making chemical in the retina and protects surface of eye
3 food source of Vitamin A
Fish liver oil, liver, carrots
3 food source of Vitamin A
Butter, fish liver oil, liver, carrots
Effect of deficiency of Vitamin A
Night blindness, and damaged cornea
Effect of deficiency of Vitamin C
Scurvy
Use of Vitamin C
Needed for cells and tissues to stick together
Food source of Vitamin C
Fresh fruit and vegetables
Use of vitamin D in body
Absorb calcium and phosphate ions from food
Effect of deficiency of Vitamin D
Rickets, caused by weak bones
Food source for Vitamin D
Dairy, oily fish
Why is water essential in the diet
Solvent used to transport components of blood, and for temperature regulation (sweating)
Why is dietary fibre essential in diet
Cannot digest cellulose, helps movement of food through intestine, prevents constipation and bowel cancer
Foods with good dietary fibre value
Fruit, vegetables and grains like oats
What glands secrete amalayse
Salivary glands through saliva, and pancreas
Lipid digestive route
Lipid - Lipase - glycerol and 3 fatty acids
Proteins digestive route
protein - pepsin/trypsin - peptides - peptidase - amino acids
Carbohydrates digestive route
Starch - amylase - maltose - maltase - glucose
What determines how much energy you need in a day
Activity levels, age and pregnancy
Define digestion
Breaking down large insoluble molecules of food into small, soluble molecules
Define assimilation
Building large biological molecules from small soluble molecules
Where does ingestion occur
Mouth
How does mechanical digestion occur in the mouth
Chewing - increases the surface area for enzymes and eases swallowing
How does chemical digestion occur in the mouth
Saliva containing amylase in released and also aids swallowing
Amylase optimum pH
7
What happens when amylase enters the stomach
It becomes denatured
What is a bolus
When food is shaped into a ball by the tounge and pushed to the back of the mouth
Purpose of the epiglottis
Blocks food entering the trachea
What is peristalis
Musular contraction that moves food through the alimentary canal
Purpose of contraction of the stomach wall
Maximise contact between enzymes and food
Pepsin optimum pH
2
Purpose of hydrochloric acid
- Pepsin optimum pH
- Kill bacteria and fungi on food
First section of small intestine
Duodenum
Where is bile made
Liver
Where is bile stored
Gall bladder
Functions of bile
- Neutralise stomach acid on food entering duodenum
- Emulsify lipids by breaking large droplets into small droplets (increasing surface area)
Second part of small intestine
Ileum
How are the villi in the ileum specialised for absorption of molecules by diffusion
- Large surface area - folding of ileium, villi and microvilli
- Short diffusion distance - villi are only 1 cell thick
- High concentration gradient - capillary netwrk and lacteals under villi
How are the villi in the ileum specialised for absorption of molecules by diffusion
- Large surface area - folding of ileium, villi and microvilli
- Short diffusion distance - villi are only 1 cell thick
- High concentration gradient - capillary netwrk and lacteals under villi
What happens in the colon
Reabsorption of water
What happens in the rectum
Storage of faeces
What happens in the anus
Faeces are egested
