nutrients Flashcards
what is a nutrient?
- any food component that serves these purposes; provision of energy, provision of raw material for building of tissues + regulation of bodily functions
what are micronutrients?
- vitamins and minerals as only need to consume a few grams a day
what are macronutrients?
- carbohydrates, fats and proteins as consumed in large quantities
what do carbohydrates contain and what are they apart of?
- contain at least 2 hydroxyl groups
- part of every building block of nucleic acids
what are the main roles of carbohydrates?
- provide a source of energy
- offer external protection
- assist cells in recognising molecules when attached to proteins/ lipids via glycosylation
- in form of ribose/ deoxyribose; building block of nucleic acid
what bond is formed in carbohydrates?
- glycosidic bonds
- link between hydroxyl groups and shed water to form bond
what are monosaccharides?
- simplest carbohydrate
- named according to number of carbon atoms
what are oligosaccharides?
- when 2 to 10 monosaccharides link covalently via glycosidic bonds
what are disaccharides?
- formation of two monosaccharides
what is maltose made of?
- glucose + glucose
what is sucrose made of?
- glucose and fructose
what is lactose made of?
- glucose and galactose
what are polysaccharides? given an example
- formed from more than 10 monosaccharides
- not readily associated with energy provision
- cellulose is a polymer of glucose
where is cellulose found and what is its role?
- found in plants and is the main solid constituent providing support
- major constituent of dietary fibre
what is starch?
- major form of starch
- found in seeds and plants
- mixture of amylose and amylopectin
describe simple and complex carbohydrates
- simple= 1-3
- complex= 3-10+ monosaccharides
describe glycogen
- structurally similar to amylopectin
- major source of stored carb in the body
describe where lipids are found and the roles they play
- exists as large tissue in adipose
- vital constituent of membranes, hormones and vitamins
what are the common features of lipids?
- low solubility in water
- large store of energy
what are fatty acids?
- simplest form of lipids
- organic acids containing lots of carbon atoms (12-26)
- consists of long carbon chain with hydrogen atoms all around and a carboxyl group at one end
what are saturated fatty acids?
- when all carbons are linked by single bonds
- no room for more atoms
what are unsaturated fatty acids?
- presence of double bonds means they can receive two H to become single
describe triglycerides
- most abundant lipid category, constitutes 95% dietary fat
- serves as energy depots
- consists of a glycerol unit and three fatty acids
what bonds are found in triglycerides?
- ester bonds
what are steroids and phospholipids?
- found in cell membrane
- creates a strong structure for membrane to be stable
what are phospholipids?
- contain a hydrophilic head and a hydrophobic tail
- tail faces inwards and hence doesn’t mix with water
what does hydrophobic mean?
- lipids are not soluble in water
describe vitamins and minerals
- compliment carbs, fat and protein
- no energy value
what is the role of vitamins and minerals?
- vital regulators of numerous bodily functions
- involved in energy provision during exercise
what are vitamins classified as?
- water or fat soluble
what is the role of B1 ( thiamine)? vitamin
- found in active site of pyruvate dehydrogenase
what is the role of B2 (Riboflavin) ? vitamin
- precursor of coenzymes for redox reactions
what is the role of B6? vitamin
- coenzymes for aminotransferases and neurotransmitters
what is the role of B12? vitamin
- serves as enzyme in fatty acid processing
what is the role of Vitamin A ?
- contained within retinas of the eye
what is the role of Vitamin D?
- involved in calcium absorption and hence bone health
what is the role of folate? vitamin
- synthesis of DNA
what is the role of pantothenate? vitamin
- contributes to coenzyme A
what is the role of niacin? vitamin
- precursor of NAD and NADP
describe sodium and its role= mineral
- main cation in extracellular fluid
- needed for electrical transmission in nerves and muscles
- maintains water content in various compartments of the body
what is it called when sodium content is abnormally low?
- hyponatremia
- caused when you sweat too much so low salt content
describe the role of potassium = mineral
- interact with sodium to maintain fluid balance and electrical impulses
what is calcium important for? mineral
- critical compartment of bones and blood clotting
what role does magnesium play? mineral
- cofactor for 100s of enzymes
what does iron help in? mineral
- embedded in proteins handling oxygen and involved in the electron transport chain
what is copper used for= mineral
- cofactor for cytochrome C
- key component of the electron transport chain
what is the role of zinc? mineral
- sits in the active sites of around 200 enzymes including carbonic anhydrase that helps get rid of carbon dioxide
what is manganese? mineral
- cofactor for 100 enzymes involved in metabolism
describe chlorine and its role = non metal mineral
- main anion in extracellular fluids where it interacts with sodium to maintain fluid balance and electrical charges across membranes
- production of digestive HCL acid
what is the role of phosphorus = non metal mineral
- phosphorus groups are covalently attached to a vast array of biological compounds
