Nutrients Flashcards
What is a nutrient and what are the 6 main groups of nutrients
a substance/chemical that is essential for life and reproduction
6 main groups:
- carbohydrate
- lipids
- protein
- vitamins
- minerals
- water
What are essential nutrients
these are nutrients that are not produced by the body and needs to be obtained from an external source (food) this is because:
1. organism cannot synthesise
2. organism can produce but not in sufficient quantities
what are the 4 most common micronutrient deficiencies
iron
iodine
vitamin A
zinc
what are the 8 micronutrients which are essential for crops and what are the effects of deficiency
boron
chlorine
copper
iron
manganese
molybdenum
nickel
zinc
deficiency of one or more of these affects both yield and quality of crops
What is the link between deficient crops and human deficiencies of nutrients
low trace elements in stable grains of essential nutrients for humans can lead to deficiency
What are the 2 groups of nutrients
Macronutrients
- large quantities needed (10-100g) per day
- carbohydrates, proteins and lipids
micronutrients
- minute quantities (micro/milligrams)
- vitamins, minerals and trace elements
what are catabolic and anabolic molecules and what is the link between the two
catabolic
- metabolic pathways that break down molecules into smaller units
- carbohydrates, lipids and proteins
anabolic:
- chemical reactions that synthesise molecules out of broken down ones
link:
- recycling of complex molecules
- both are balanced to help the body function
What are the 2 forms that carbohydrates are present in
simple carbohydrates:
- glucose
- fructose
- other sugars
compound carbohydrates:
- starch in plants
- glycogen in animals in the muscle and liver (polymers of glucose)
- metabolised to CO2 + H2O + energy
What is the structure of glycogen
branched biopolymer
- linear chains of glucose residues
- chains branching off every 10 glucoses
What is the structure of starch and what foods can are high in starch
structure
- large number of glucose units joined by glycosidic bonds
foods:
- potatoes
- wheat
- maize (corn)
- rice
What are the function of proteins to the body and what are they made from
proteins build body parts they are essential for:
- growth
- repair of worn-out tissues
- resistance against infections
made from amino acids
what are the 9 essential amino acids
histidine
isoleucine
leucine
lysine
methionine
phenylalanine
threonine
tryptophan
valine
all required from diet
proteins are found in the in animal and plant foods what is the difference between the two
animal proteins:
- complete proteins as they contain all amino acids
plant proteins:
- incomplete proteins as some are low in methionine, lysine and tryptophan
- there needs to be supplemented with grains, nuts, seeds and legumes
Lipids chemical properties, examples and what are they essential for
chemical property
- water insoluble (hydrophobic)
example:
- triglycerides
- phospholipids
- sterols (cholesterol)
essential for:
- brain
- nerves
- hormones
- absorption, transport and storage of fat soluble vitamins (A,D,E and K)
Triglycerides can be a fat or an oil depending on the bonds it has fats have what type of bonds?
saturated or monounsaturated (saturated = single bonds, unsaturated = contain at least 1 double or triple bond)
solidifies easy = solid at room temp
found in land animal sources
Triglycerides can be a fat or an oil depending on the bonds it has. Oils have what type of bonds?
polyunsaturated fatty acids (multiple double or triple bonds)
harder to solidify therefore liquid at room temperature
triglycerides as oils at room temp can be found in what sources
aquatic animals
- polyunsaturated fatty acids and their lipids
plant sources:
- mustard oil
- soybean oil
- sunflower oil
- corn oil
however:
- coconut and palm oil contain large portions of saturated and monounsaturated fatty acids therefore are solid at room temperature
what are the 2 groups of micronutrients
vitamins and minerals
Why are vitamins needed
cannot be synthesised in the body and are essential for metabolism and utilisation of carbohydrates, proteins and lipids
they also function as coenzymes
Which vitamins are water soluble and which are fat soluble
water soluble
- B complex vitamins (B1, B2)
- vitamin C
lipid soluble
- A
- D
- E
- K
What is the chemical names for Vitamin A
There are 3 forms of Vitamin A :
- retinols
- beta-carotenes
- carotenoids
What is Vitamin A needed for?
skin, hair, eyes (healthy vision), increases resistance to infection ( used in T cell differentiation)
Vitamin A deficiency can cause:
xerosis cutis (dry skin)
- retinoic acid needed for a growth factor for epithelial cells and control gene transcription
low resistance to infection
eye disorders (vit A deficiency is the leading cause of preventable childhood blindness
What are the different eye disorders which Vit A deficiency cause
xerophthalmia (loss of tears)
- loss of goblet cells in conjunctiva
- no mucus therefore debris accumulates in the eye forming Bitot’s spots due to dryness
keratomalacia
- atrophy of the corneal epithelial cells
- opaque cornea and blindness
night blindness
- retinal (Vit A) and opsin form rhodopsin in retina
- rhodopsin is a pigment for low light detection
Vitamin A toxicity (consumption of too much Vitamin A can be described from the case study of Douglas Mawson exploring the Antarctic with Mertz and Ninnis. How did vitamin A toxicity occur in this case study?
- Ninnis fell through a crevasse with sled and food
- forcing Mertz and Mawson to feed on their sled dogs for 10 days
- Husky’s liver contain extremely high levels of Vitamin A (100g is toxic to humans)
causing liver damage to Mertz and Mawson - between them they consumed 6kg
Vitamin A toxicity (consumption of too much Vitamin A can be described from the case study of Douglas Mawson exploring the Antarctic with Mertz and Ninnis. What were the symptoms they faced and why did Mertz suffer more?
symptoms:
- dizziness, nausea, abdominal pain, mucosal fissuring, skin/hair/nail loss, yellowing of the eyes/skin
- irrationality
mertz suffered more due to finding muscle tissue tough and difficult to eat therefore at more of the liver and softer tissues
- lost the will to move and went mad
- he died before making it to the base