Food and Digestion Year 9 Flashcards
What does a healthy diet contain?
The right balance of the different foods (carbs, lipids (fats and oils), proteins, vitamins minerals, fibre and water) that you need and the right amount of energy.
Vitamins and minerals are…
present in smaller amounts than other food groups and needed for healthy functioning of the body.
What does the body use to release energy?
Fats, carbs
What does the body use for growth and repair?
Protein
What does vitamin C do?
Keeps lining tissues healthy
What happens if someones deficient in vitamin C?
They can develop scurvy
What does Vitamin D do?
Aids calcium absorption
What happens if your deficient in Vitamin D?
They can develop rickets
Why is iron needed?
To make haemoglobin
What happens if your deficient in iron?
They can develop the deficiency anaemia
Why is fibre needed?
To aid peristalsis for a healthy gut
Why is water needed?
Component of cytoplasm
Makes up the plasma of blood
If cells become dehydrated chemical reactions can’t take place
What happens if a person diet isn’t balanced?
Malnourishment
Overweight
Underweight
Deficiency Disease
What is BMI?
A measure adults use to see if they are a healthy weight for their height. The ideal BMI for adults is 18.5 - 24.9
What can obesity raise the risk of?
Arthritis Type 2 diabetes High BP Heart disease Cancer
What happens if someone eats less than their body needs?
Lose mass Starvation which causes: • Muscles to waste • Periods to stop • Prevents the immune system from working properly
What is the metabolic rate?
The rate at which all the chemical reactions in the body are carried out
How does the metabolic rate vary?
How active you are
Fat to muscle ratio
What is the function of the mouth?
To break down food into smaller easily digestible parts
What is the function of the salivary gland?
!3£2&3!3&2!3!
What is the function of the oesophagus
Receives food from mouth
Uses muscle contractions called peristalsis
Delivers food to stomach
Function of the stomach
Holds food while enzymes break it down
What is the function of the liver
Process the nutrients absorbed from the small intestine
Function of small intestine
Breaks down food using enzymes
Function of pancreas
Makes enzymes
Function of large intestine
Process waste
Function of rectum
Received and stores waste
Function of anus
Expels waste
A model to describe digestion
Visking tube = gut
Visking tube contents = food in the gut
Fluid surrounding Visking tube = bloodstream
Chemical test for carb
Iodine test
Red to blue / black
Test for protein
Biuret test
Blue to violet
Test for simple sugars
Benedicts test
Blue to orange
Test for fats
Water and ethanol
Clear to milky
Order of digestive cycle
Mouth Oesophagus Stomach Small Intestine Large Intestine Rectum Anus
Molecules to big to be absorbed by the body
Fats
Proteins
Starch
Molecules that can be absorbed by the body
Vitamins
Minerals
Some sugars
What are enzymes?
Biological catalysts
Speed up rate of reactions
Work best at body temperature
Activity affected by pH
What is chemical digestion?
When large insoluble molecules are broken down in the gut by endings to form smaller molecules that can pass through the wall of the small intestine.
What is physical digestion?
Chewing, churning by the muscle wall of the stomach and the emulsification of the fats with bile
