Diet Flashcards
Function of carbohydrates:
Broken down in respiration, to release energy in the form of ATP
Functions of proteins:
-Growth and repair of cells and tissue
-Fuel for respiration
-Structural molecules like collagen and keratin
-Controlling chemical reactions - enzymes
-Messenger molecules - hormones
-Combating disease - antibodies
-Transport - eg haemoglobin and cell membrane proteins
Functions of lipids:
-Store of energy
-Thermal and electrical insulation
-Fuel for respiration
-Buoyancy - helps marine animals like whales float
What % of the energy we use every day is just to keep our body running?
70%
What are 3 examples of energy uses in our body to keep us alive?
-To keep our hearts beating
-Transport nutrients (active transport)
-Repair our cells
How can we investigate the energy content of a food sample?
-Burning a known mass of food and using the thermal energy released to heat water
-Measure 25cm3 into a boiling tube and record the initial temperature
-Light the foodstuff over a bunsen burner, then hold under the boiling tube of water to heat it
-Keep relighting the foodstuff until it will no longer burn
-Measure the final temperature of water and calculate temperature change
What is the equation to calculate the energy content of food?
Energy released (J) = mass of water (g) x temperature rise (C) x 4.2 / mass of food sample (g)
What is the function of iron?
Forms part of the haemoglobin which binds to oxygen.
What is the deficiency disease of iron?
Anaemia.
What is the function of calcium?
Needed to form bones and teeth.
What is the deficiency disease of calcium?
Rickets
What is the function of vitamin A?
Making a chemical in the retina and also protects the surface of the eye.
What is the function of vitamin C?
Needed for cells and tissues to stick together.
What is the function of vitamin D?
Needed to absorb calcium and phosphate ions from food.
What is the deficiency disease of vitamin A?
Night blindness and damaged cornea.
