1 Nutrition, Homeostasis, Energy Reactions Flashcards
List the essential components of the diet and explain why they are essential.
Protein - supplies amino acids essential building blocks for most cell components, muscle fibres and structures.
Lipids - provide energy and when stored can supply warmth.
Carbohydrates - provide energy
Vitamins and minerals - necessary for cell components
Fibre - needed to help with digestion/ Norma, functioning of GI tract.
Water - for essential cell function
Define and give approximate value to the components of your daily energy expenditure.
BMR - basic metabolic rate. The energy used in basic cell and bodily functioning. For an average man this is around 17,000 kcal. For not obese people this = kg x 100
Physical exercise - amount depends on the time spent active each day. Aprox 2hrs a day = +60/70%
Diet induced thermogenesis (DIT) - Digestion and processing of food - about 10% of the energy gained from food
Explain the clinical consequences of protein and energy deficiency in humans
Energy deficiency leads to weight loss as the body metabolises stored fats and proteins for energy. This can lead to diseases such as marasmus - muscle wasting and loss of body fat, no oedema, thin dry hair, diarrhoea, possible anaemia. Growth development issues may occur, immune system affected.
Protein deficiency leads to muscle wasting, impaired physical and mental development, weakened immune system and diseases such as kwashiorkor - apathetic, lethargic, anorexic, odema, heptatomegaly, ascites, low serum albumin and often anaemic.
Determine the BMI of a patient and interpret the value
Mass/ height2 <18.5 underweight 18.6-24.9 fine 25-29.9 overweight 30 - 34.9 obese 35+ severely obese
Define obesity and describe the factors involved in the regulation of body weight.
Obesity is a BMI above 30.
Regulated by energy intake vs energy expenditure effected by both genetics and the environment.
Define homeostasis and explain its importance
The control of an internal body environment within set limits in a dynamic equilibrium.
It is important in the supply of nutrients and O2, for blood flow, body temperature and the removal of metabolises.
Define cell metabolism and explain its functions
Metabolism is the process which derives energy and raw materials from food stuffs to use for support, repair, growth and activity of the tissues in the body.
It provides: ATP Building block molecules Organic precursor molecules e.g. Acetyl CoA Biosynthetic reducing power.
Describe the origins and fates of cell nutrients.
Cell nutrients come from the food we eat or are the result of catabolism of different stores. They are used for energy, interconverted to other useful substances, stored or lost from the kidneys/lungs.
Describe the relationship between catabolism and anabolism.
Catabolism is the break down of molecules to release energy in oxidative processes. Catabolism can also form the building blocks needed for anabolism.
Anabolism is synthesising larger components from smaller. It requires energy and is reductive.
Explain why cells need a continuous supply of energy.
Biosynthetic work- synthesis of cellular components.
Transport work across cell membranes - active transport.
Specialised work e.g. Mechanical/electrical/osmotic
Explain the biological roles of ATP, creatine phosphate and other molecules containing high energy of hydrolysis phosphate groups.
ATP and similar chemical act as a currency of energy and store energy released from catabolism so It can be used for cell functions.
Creatine phosphate is a chemical that stores the energy from ATP longer term.
Explain the roles of redox reactions and H-carrier molecules in metabolism.
Carry reducing power needed for ATP synthesis and biosynthesis. Redox reactions are needed to reduce these carriers initially. Comstant levels of H carriers.
Explain the roles of high and low energy signals in regulation of metabolism
High energy signals (e.g. Lots of ATP) trigger anabolism and the storage of molecules that can produce energy. Low energy signals trigger catabolism so more energy can be produced.
