Nutrition And Digestion Flashcards
What are carbohydrates
Nutrient that is sourced from grains and potatoes , it is an energy source for respiration and compromises about 50% of total calorie intake . It is rarely sufficient , anorexia nervosa if total calorie intake is severely restricted
What are proteins
Nutrient sourced from meat , fish and nuts . It is used for growth and repair of tissues , to make structural proteins like collagen and for functional proteins , enzymes and hormones . It compromise about 15% of total calorie intake . Deficiency symptoms are kwashiorkor - swollen belly due to lack of blood proteins affecting water balance of blood.
What are lipids
Fats and oils sourcesd from dairy products , eggs , meat , oily fish , plant oils. It’s a component of cell membranes , instigation , energy store . It compromises 30% of total calorie intake , it is rarely deficient
What is vitamin a (retinol)
Sourced from green and orange vegetables ,fish liver oils and dairy products e.g butter , margarine . It’s function is a component of visual pigments in eye , maintenance of epithelial tissue , helps prevent damage to cell membranes . Deficiency symptoms include night blindness / damaged cornea , problems with vision , dry , scaly skin
What is vitamin c ( absorbic acid)
Sourced from Fruits and vegetables , especially citrus fruits. Used in collagen synthesis ( such as for bones , cartilage and gums), it is an antioxidant . Deficiency symptoms include scurvy , degeneration of teeth , skin and blood vessels
What is vitamin d
Sourced from dairy products , egg yolk , fish liver oil , also made in the skin in the presence of sunlight . It aids in absorption of calcium and phosphorus and promotes bone growth . Deficiency symptoms are rickets , bone deformities in children and bone softening in adults
What is calcium
Sourced from dairy products , egg yolk , fish , bread , dark green vegetables . It is required for bone and teeth development . Deficiency symptoms are rockets in children and retarded growth
What is iron
Sourced from red meat , liver , eggs , leafy green vegetables . It’s function is a component of haemoglobin and deficiency symptoms are anaemia
What are minerals
Like calcium - to strengthen bones . Iodine-for energy production. Iron-prevents fatigue. Minerals regulate and control the normal function of human and animal tissues ,muscles and organs. It plays a role in metabolism, prevents osteoporosis, and prevents goitre( affects metabolic rate ) . It is used to make haemoglobin in red blood cells and it prevents anaemia. You would need it in sport when training hard and competing. You can get minerals through fruit , vegetable and fish .
What is fibre
It can’t be digested , it fills you up and keeps you ‘regular ‘ . It prevents constipation and it aids peristalsis . it is needed in sport for healthy digestion and helps with weight control. You can get it from fresh fruit , vegetables and whole grain cereals
What does water do
Maintains fluid levels and is useful in sport when you sweat and it prevents dehydration
Why are carbs useful for sport
Starch (complex ) ( slow realising energy )
Sugars (simple ) (provides quick realising energy) . It is useful in running , training athletes will eat more carbs and Marathon runners will load before the event. You can get carbs from pasta, cereals rice and potatoes
How are fats ( lipids ) useful in sport
Unsaturated fats are healthy . Too much saturated fat from animal products can lead to heart disease . Fats provide slow relapsing energy ( because of stores it ) , insulation and is useful for making cell membranes . 25% of our diet should be fat. It is useful in sport for walking and low Impact excercise - it produces energy too slowly to be used when working hard
How are proteins useful in sport
They build and repair muscle. Are used for growth. We only need 15% of our diet to be protein. You need it in sport when training hard and recovering from injury. Power athletes such as weightlifters will eat for protein. You can find it in the meat, pulses and fish.
How are vitamins useful in sport
A-is for vision
B-for energy production and stress reduction
C- to keep skin healthy
B- to help bones and teeth.
It is essential for normal metabolism and growth, required in small amounts, prevents night blindness, and maintains cell metabolism. You need it in sport for normal metabolism and growth. You can get it from fresh fruit and vegetables.
How do you measure energy contents of food
- Measure out 20 cm³ of water with a measuring cylinder, then transfer it to a boiling tube.
- Clamp it , and take the temperature of the water, record this as your initial temperature.
- Weigh a piece of food. Record this as its initial mass. Attach it to the end of a mounted needle.
- light a splint with a Bunsen flame, then take the splint back to your bench. Hold the food above the burning splint until the food starts burning, then place it under the boiling tube and allow the heat produced to warm the water in the boiling tube.
- When the food stops burning, record the final temperature of the water and the final mass of the food.
How do you process your results to measure the energy contents of food.
- Water takes 2.2 J of energy to heat 1 cm³ of water by 1°C.
Energy released/J = volume of water/cm3 x temperature rise/°C x 4.2 - To work out how much food was actually burned and released their energy by: final mass of food - initial mass of food,
- To convert the answer into kilojoules per hundred grams we
First , energy produced
———————
Mass of food that burned away. This gives the answer in J/G
Second , we times this by 100 to convert the total into J/100g
Finally, we divide that result by 1000 as there are 1000j in 1 kj - giving the energy content of that food in kj / 100g
How do you test reducing sugars
Mix a sample of food with 2 ml water and Benedicts solution , place it in the water bath at 90 degrees , leave it there for 3-4 minutes then carefully observe the colour change - blue -green -yellow - brick red
Why would a vegetarian diet be inadequate
Plant protein is not very concentrated in plant cells; animal cells have far higher protein concentration - especially muscle cells. Plant protein is relatively poor in the amino acid lysine but okay in methionine , it is the reverse with legumes so together they are complimentary. Vegetarian diets are adequate in in protein if they contain rice and beans.
What are saturated fatty acid’s associated with
They are found in red meat and are associated with coronary heart disease is and atherosclerosis .
What is the body mass index
It is used to assess what a persons weight should be, the body mass(kg) is divided by the square of the persons height. If the resulting calculation is below 20, a person is underweight 20 to 24.9 is normal 25 to 29.9 is over weight 30 - 40 is moderately overrate and over 40 is severly overweight. Factors affecting BMI include; metabolic factors, the diet, levels of physical activity, eating behaviour, genetic factors, hormonal factors and psychological factors
How is a food bolus moved down the Oesophagus
The oesophagus and peristaltic movement along it towards the stomach, waves of muscle contraction push the food bolus along.
What is in the stomach
A very muscular wall , two contractile sphincters ( one at each end ) and glands in the wall that secrete gastric juice containing Hydrochloric acid at PH2 and the protein digesting enzyme (protease )called pepsin. Mucus is secreted by goblet cells in the gastric glands and this protects the stomach lining from being digestive by gastric juice. The sphincters contract when food is in the stomach during muscular contractions of the stomach wall. This prevents the stomach contents from being squeezed out the stomach before it’s digestions of protein is complete , the food then enters the duodenum.
What are enzymes
Enzymes are catalysts made of protein molecules. Catalysts are substances that speeds up a chemical reaction, often very specifically but remain unchanged at the end of the reaction.
