Science Flashcards
What are carbohydrates needed for?
Release energy
Which food group is needed for energy?
Carbohydrates
Examples of carbohydrates
Bread, rice, pasta, potatoes
What kind of enzymes break down carbohydrates?
Carbohydrase
What food group does starch belong to?
Carbohydrate
Which enzyme breaks down starch?
Amylase
What is starch broken down into?
Glucose
Examples of foods containing proteins
Nuts, fish, eggs, pulses, meat, tofu, soya, lentils
What kind of enzymes break down proteins?
Protease
What are proteins broken down into?
Amino acids
Why are proteins needed?
Growth and repair
What are lipids?
Fats
What kind of enzyme breaks down fats?
Lipase
What are fats broken down into?
Fatty acids and glycerol
What kind of foods contain fats?
Butter, Margarine, Oil
Why are fats needed?
Insulation, store energy
What is the name of the food pipe leading to the stomach?
Oesophagus
What is the name of the pipe leading to the lungs?
Trachea
Where does the trachea lead?
Lungs
Where does gas exchange occur?
Alveoli
What is respiration?
Chemical reaction that releases energy from oxygen and glucose
Where in the cell does respiration happen?
Mitochondria
What gas is needed for respiration?
Oxygen
What gas is made in respiration?
Carbon dioxide
What are the two reactants in respiration?
Oxygen and glucose
What are the two products in respiration?
Carbon dioxide and water
Why is fibre needed in the diet?
Prevents constipation
Keeps intestines healthy
Helps you stay full
What kind of food contains fibre?
Fruit and vegetable
Why do you need iron in the diet?
Prevents anaemia / helps your red blood cells carry oxygen
Describe the colour change for a positive Biurets test
Blue to lilac/purple
Describe the test for fats/lipids in food
Add ethanol, then cold water
Describe the change in ethanol if fats are present
From colourless and clear to white emulsion
Describe the oesophagus
Pipe that carries food to the stomach
Describe the trachea
Pipe that carries air to and from the lungs
Describe physical digestion in the mouth
Using your teeth to physically break down food
Describe chemical digestion in the mouth
Amylase in saliva chemically breaks down food
What happens to food in the stomach
Chemically broken by pepsin (a protease enzyme) and mixed up to make it a liquid
What happens to food in the small intestines?
Chemical digestion by enzymes
Nutrients absorbed into blood
What happens in the large intestines?
Water and minerals absorbed
How do you calculate BMI?
Weight / height squared
Weight in kg
Height in metres
Why can visking tubing be used to model the intestines?
Small holes which let small molecules and water through but not big ones
Describe mechanism of breathing in
Diaphragm and intercostal (rib muscles) contract
Diaphragm moves down
Ribs move up and out
Volume increases
Pressure decreases
Air moves in
Describe mechanism of breathing out
Diaphragm and intercostal (rib muscles) relax
Diaphragm moves up
Ribs move in
Volume decreases
Pressure increases
Air moves out
Difference between breathing and respiration
Breathing is moving air in and out of lungs
Respiration is releasing energy from food in your cells
How are alveoli adapted for gas exchange?
Lots of them - high surface area
Moist surface - to dissolve the gases
Small so high surface area to volume ratio
Thin so easy for gases to diffuse
Close to lots of blood vessels so easy for gases to move in and out from blood
Name equipment that can be used to measure lung volume
Spirometer and peak flow meter
Define lung volume
Volume of air in your lungs
Define breathing rate
Number of breaths per minute
What is the job of the nucleus?
Controls the cell and its activities
What is the job of the cytoplasm?
It’s where the chemical reactions happen
What is the job of the cell membrane?
Controls what goes in and out of the cell
