Nutrients Flashcards
What is the function of carbohydrates?
the main source of energy for many cells
What are the main subunits of carbohydrates? + give examples of each
simple sugars (e.g. fructose, glucose), double sugars (sucrose) and complex sugars (glycogen, starch)
What is glucose used for in humans?
Glucose is soluble so it is easily transported in blood and dissolves in the cytoplasm of cells. It is oxidized in respiration to release energy for active transport, cell division, muscle contraction and the manufacture of large biological molecules
What happens to excess carbohydrates in humans?
It can be stored as glycogen and as fat
What are fats/lipids used for in humans?
insulation (e.g. electrical insulation around nerve cells), energy, hormones (made from cholesterol) and protection. Insoluble in water – thus, they are excellent stores of energy, and form barriers between watery environments, such as between a cell and its surroundings
What are fats/lipids made up of?
Formed by the condensation of three molecules of fatty acid with one molecule of glycerol
What are proteins used for in humans?
the active site of enzymes and the binding site of antibodies
What are proteins made up of?
long chains of subunits called amino acids
What can a deficiency of protein cause?
poor growth; in extreme cases, may cause marasmus or kwashiorkor
What is vitamin D used for in humans?
helps to properly deposit calcium in our bones
What can a deficiency in vitamin D cause?
Deficiency of vitamin D leads to rickets/osteoporosis (lack of calcium leads to these sicknesses)
What can a deficiency in vitamin C cause?
leads to scurvy – symptoms include: bleeding gums, sore & weak joints and poor healing of wounds - this happens because membranes in the skin and blood vessels do not form properly
What can a deficiency in calcium cause?
causes rickets in children, making the bones soft and eventually deformed by the mass of the body, and osteoporosis in adult, giving them fragile bones. Teeth are more vulnerable to decaying
What can a deficiency in iron cause?
causes anemia which often makes people feel tired/weak – this is because there isn’t enough haemoglobin in the red blood cells, so not enough oxygen is carried by the blood
What is fiber?
The indigestible part of food, largely cellulose from plant cell walls
