Topic C - Diet and Digestion Flashcards
Name the 6 things needed for a balanced diet
Carbohydrates - starch
-sugar
Fats/ Oils (lipids)
Protein
Fibre (roughage)
Vitamins + Minerals ( fruit + veg)
Water
Function of carbohydrates ( give examples)
Energy -heart beat
- breathing - body temp. - work and other movement ( muscle fibres)
Excess stored as body fat
eg. starch = bread, potato
sugar = sweets, cake
Function of fats/oil ( give examples)
Energy -heart beat
- breathing - body temp. - work and other movement ( muscle fibres)
Used in construction of cell membranes
Excess stored as body fat
eg. butter, cheese, milk
Function of protein ( give examples)
Build cells
Make enzymes
In starvation protein can be used as last resort of energy
eg. meat, eggs. beans
Function of fibre ( give examples)
Helps prevent constipation
eg. bran, cabbage, wholemeal
Function of water (give examples)
Transports substance in blood solution
Medium for digestion
Medium for excretion
Temp control through evaporation
eg. drinks most food
Name different types of vitamins and minerals
Vitamin A Vitamin B (complex) Vitamin C Vitamin D Iodine Iron Calcium
Function of Vitamin A ( give examples)
Promotes healthy eyesight (night vision)
Promotes healthy skin
Promotes resistance to disease
eg. carrots, liver eggs
Function of Vitamin B complex ( give examples)
Part of many chemical processes in cells particularly respiration
eg. whole meal bread, brown rice
Function of Vitamin C ( give examples)
Helps to heal wounds
Helps rebuild new tissue
Promotes healthy connectives
eg. citrus fruit, tomatoes, fresh green vegetables
Function of Vitamin D ( give examples)
Maintains level of calcium in blood
To form strong bones + teeth
eg. cod liver oil, egg yolk, milk
Function of iodine ( give examples)
Used to make thyroxin in thyroid gland
Function of calcium ( give examples)
Formation of teeth + bones
Helps control muscle contraction
Important in clotting of wounds
eg. milk, cheese, soya flour
Definition of enzymes ( 5 things )
Potent biological catalyst Proteins Made by living cells Control metabolism Sensitive to change in PH +Temp.
Explain enzyme action ( 3 things )
Each enzyme has an ACTIVE SITE
SUBSTRATE (starch molecule) fits in to active site (like key in a key whole)
Substrate split into small maltose molecules (PRODUCTS)
Give example of enzyme reaction for starch molecule
food group , enzyme , breakdown product
- Starch molecule
- Carbohydrase
- Glucose
Give example of enzyme reaction for fat molecule
food group , enzyme , breakdown product
- Fat molecule
- Lipase
- Fatty acids + glycerol
Give example of enzyme reaction for protein molecule
food group , enzyme , breakdown product
- Protein molecule
- Protease
- Amino acids
List the order of structures of the digestive system
Mouth Oesophagus Stomach ( Liver, Gall Bladder, Pancreas -food does not pass through) Small Intestine Large Intestine Rectum Anus
Function of mouth (pH 7)
Saliva moistens food
Teeth breakdown food (mechanical digestion)
Starch digestion begins - salivary amylase (enzyme)
Function of oesophagus
Bolus of food passed down into stomach by peristalsis
Function of stomach (pH 2)
Hydrochloric acid (pH 2) added to kill bacteria
Food churned by muscular wall
Protein digestion begins- protease released (enzymes)
Function of liver
Produces bile (alkaline)
Function of gall bladder
Stores bile which emulsifies lipids (fats)
Bile passed down b-duct to small intestine
Bile alkaline- neutralises stomach acid
Function of pancreas
Releases pancreatic juice
Produces digestive enzymes (protease, carbohydrase, lipase)
Which are secreted into small intestine
Function of small intestine
Long, Narrow , Large surface Area
Digestion is completed (enzymes )
Nutrients are absorbed through villi on wall into bloodstream
Function of large intestine
Water is absorbed to maintain hydration
Function of rectum
Faeces compacted and stored
Function of anus
Faeces are egested
Pass out via anal sphincter
Explain Peristalsis
Muscles behind bolus (food) contract and muscles in front relax
This squeezes the food along the gut wall towards the anus
Definition of digestion
Breakdown of food ( so can be absorbed)
Definition of absorption
Products of digestion absorbed into blood circulation system
Definition of assimilation
Products of digestion absorbed from blood into body cells used for energy growth and reapair
Definition of egestion
Undigested food expelled from body as faeces
Definition of excretion
Removing waste made in our cells
Definition of epiglottis
Flap of cartilage that closes off the trachea when food or drink is swallowed
What is the test for starch?
Iodine= Clear > Dark black/blue
What is test for glucose?
Benedict’s solution = Light blue > Orange/brick red
What is test for protein?
Copper Sulphate solution + Sodium hydroxide solution = Clear cloudy > Lilac/purple
What is test for fat
Ethanol (alcohol) + water = separation with oil sitting on top