Lec 6 - Nutrition and Diet Flashcards
outline what metabolism is, and why its necessary
chemical process that is required to maintain life
oxidation path - food to energy (catabolic) - the break down of molecules to release energy in the form of reducing power
bio synthesis (anabolic) - the building of largre molecules
fuel storage
detoxification pathways
why do we need energy?
we use chemical bond energy to do work
ion transport, biosynthesis, muscle contraction, nerve conduction
what is the ATP cycle and why is it used?
ATP –> ADP + Pi
atp to adp is energy usage - WORK
adp to atp is energy production by oxidation of lipids, carbs, proteins.
it uses oxygen and gives off co2, h20 and heat
what are the units of food energy?
Kilojule - the SI unit
Calorie - in laymans means kilocalorie
1kcal = 4.2 KJ
define calorie
amount of energy needed to raise temp of 1kg of water by 1 degree celcius
what are the essential components of the diet?
carbohydrate - energy supply proteins - energy and amnio acids fat - energy and essential fatty acids, most energy per molecule minerals - essentail vitamins - essential water - maintains hydration fibre - required for normal GI function
use of carbs in the body ?
digestion breaks all forms of carb into monosaccherides, which can be absorbed into the blood
for example sucrose, fructose, glucose, lactose
use of proteins in the body?
20 amino acids make all protein chains
9 essential amino acids we cant make and get from diet
meat has all 9
plant based does not, need variation of protein sources
use of minerals in the body?
ion gradients
calcium and phosphate also vital for bone and teeth
enzyme co factors
iron for haemoglobin
use of vitamins in the body?
Essential
if we are deficient gives many diseases
like b12 - anemia
vit c - scurvy
use of fibre in the body?
found in cereals an example is cellulose vital in GI tract function high fibre reduces cholesterol and diabetes low fibre - constipation
what are the key dietary reference values (DRV’s)?
they vary based on age, gender, activity level
the Reference Nutrient Intake (RNI) - enough for 97.5% of Pop group
the Estimated Average Intake (EAR) - middle value
the Lower Reference Nutrient Intake (LNRI) - intakes below this is insufficient for 97.5% of Population group
what is average daily energy expenditure, and what does this consist of ?
12,000 KJ / 2500 kCals for a 70kg male
9,500 KJ / 2000 kCals for a 58kg female
sum of the
basal metabolic rate (BMR) - resting activities of the body - ion transport, skeletal muscle, brain (organ) activity, maintaining body temp.
affected by body size, gender, temperature
physical activity level (PAL) - more intense exercise requires more energy
diet induced thermogenisis (DIT) - energy needed to metabolise food
how is energy stored in the body ?
rapid energy in muscles burn carbs store as fats we all have same proteins, carb amounts as we get heavier it is all in fats!
energy intake and body weight
burn more energy than we eat - loose weight
intake = expenditure - stable weight
burn less than we eat - gain weight
