Nutrition Flashcards
Define ‘Nutrition’
the science that studies the interaction between living organisms and the food they consume.
What are the 6 classes of nutrient?
Carbohydrates, lipids, protein, water, vitamins, minerals
What are the energy yielding nutrients?
Carbohydrates, lipids and protein
What are the organic nutrients?
Carbohydrates, lipids, proteins, vitamins
What are the inorganic nutrients?
Water and minerals
What does Macronutrient mean and which ones are they?
a type of nutrient required in large amounts.
Carbohydrates, lipids, water and protein
What does Micronutrient mean and which ones are they?
a type of nutrient required in small amounts.
Vitamins and Minerals.
What nutrients are used for metabolic fuels and how?
CARBOHYDRATES - the average diet provides around 45% of its daily energy from carbs, in the ideal diet this would be 55%.
LIPIDS - the most plentiful source of stored energy in the body comes from fat stores.
PROTEIN - any excess protein consumed in the diet will be used to provide extra energy
What nutrients are used for their structural properties and how?
LIPIDS - these are the primary component that surrounds our body cells.
PROTEIN - protein in connective tissue holds bones together and also holds muscle to bones
MINERALS - Such as calcium helps to strengthen bones and teeth.
What nutrients are used for their regulatory properties and how?
LIPIDS - Oestrogen is a lipid hormone used to regulate the female reproductive system
PROTEIN - Leptin is a protein that is used to regulate the size of body fat stores.
WATER - the water in sweat helps to regulate body temperature
CARBOHYDRATES - sugar chains attached to protein circumlating in the blood are used to indicate whether protein should be removed by the liver or remain in the blood.
VITAMINS - B vitamins regulate the use of macronutrients for energy
MINERALS - Sodium is a mineral that helps to regulate blood volume.
What is Nutrient Density?
a measure of the nutrients provided by a food relative to its calorie content. Nutrient dense foods contain more nutrients per Kcal and since there are over 40 essential nutrients we need from our diet consuming nutrient dense foods is important.
What is a Phytochemical?
Substances found in plant foods that are not essential in our diet but may have health-promoting properties such as reducing the likelihood of cancer
What is a Zoochemical?
Substances found in animal foods that are not essential in our diet but may have health-promoting properties such as promoting a healthy heart.
What is Malnutrition?
a condition that results from the intake of energy or nutrients which is above or below that which is optimal.
Structure of Amino Acids
All amino acids (except proline) have the same basic structure, a central carbon surrounded by a H atom, an amino group (2 H’s and an N) a Carboxyl group ( C, OH and O with double bond) and variable R group which is the part that varies and gives the amino acid its overall properties.
How many of the essential amino acids must we consume in our diet?
9 as these cant be synthesised in the body.
What bond holds amino acids together?
Peptide
What is Primary Structure?
The sequence of amino acids held together by Peptide bonds
What is Secondary Structure?
Local regular folding creating alpha-helicies and beta-pleated sheets due to Hydrogen bonding.
What is Tertiary Structure?
Further folding giving the polypeptide its overall 3d shape, due to ionic and di-sulfide bonds and van der Waals forces.
What is Quaternary structure?
When multiple polypeptides are joined together to form a molecule, such as haemoglobin which is made up of four polypeptides each with a haem group attached.
How is protein digested in the stomach?
Hydrochloric acid uncoils and denatures proteins and stiumlates the conversion of Pepsinogen to pepsin (an enzyme). Pepsin splits proteins into smaller, more manageable polypeptides and in some cases even to free amino acids.
How is protein digested in the small intestine with help from the pancreas?
Pancreatic and Small intestinal enzymes split the polypeptides further. Then the enzymes on the surface of the lumen on the SI hydrolyze these peptides and so they can be absorbed by the small intestine and taken to the liver. The liver then regulates the distribution of amino acids to the rest of the body.
What are some of the ways protein is used in the body?
STRUCTURE - Protein in prevalent in muscles, hair , teeth and bones.
ENZYMES - used to speed up metabolic processes without getting used up in the process, they are all synthesizes by the body so do not need to be consumed.
TRANSPORT - transport proteins act as shuttles in the body and can carry substances in the blood to the required organ.
PROTECTION - the skin is the primary barrier to infection and injury.
