Session 1: Nutrition, Diet and Body Weight Flashcards
What factors determine the selection of a particular substrate/pathway for ATP synthesis? (3)
- Supply of oxygen
- How rapidly ATP must be produced
- Fuel availability
What is metabolism?
Chemical processes that occur within a living organism in order to maintain life
What are the different pathways involved in metabolism? (4)
- Oxidative
- Detoxification
- Biosynthetic
- Fuel storage and mobilisation
What do you need energy for? (5)
To do work
- Biosynthetic
- Transport
- Mechanical
- Electrical
- Osmotic
Why can’t humans digest cellulose?
Humans don’t have cellulase to break down B-1,4 bond
What are the 9 essential amino acids?
- Isoleucine
- Leucine
- Lysine
- Valine
- Methionine
- Phenylalanine
- Tryptophan
- Threonine
- Histidine
What makes fat the most efficient source of energy?
Fats contain less oxygen than carbohydrate or protein - they’re more reduced so yield more energy when oxidised
What are the different types of fat and what states are they in at room temp?
Saturated - solids
Unsaturated - liquid
Trans
What are fats required for?
Absorption of vitamins A, D, E, K from the gut
Name some essential fatty acids.
Linoleic acid and linolenic acid
What are the functions of minerals?
- Ion gradients
- Structure (Ca, P)
- Signalling (Ca)
- Enzyme co-factors
- Make haemoglobin and collagen (iron)
What does deficiency of B12 and folate lead to?
Anaemia
What is a diet low in fibre associated with?
Constipation and bowel cancer
What is a diet high in fibre associated with?
Reduce cholesterol and lower risk of diabetes
How can daily energy expenditure be calculated?
BMR + DIT (diet-induced thermogenesis) + PAL (physical activity level)
Why is Basal Metabolic Rate significant?
Maintains resting activities of the body:
- maintenance of cells (ion transport across membranes; biochemical reactions)
- function of organs
- maintaining body temperature
What factors affect BMR? (5)
- Body size (surface area)
- Gender (higher in males)
- Environmental temp (increases in cold)
- Endocrine status (increased in hyperthyroidism)
- Body temperature
What are the different energy stores and when are they used?
- Creatine phosphate in muscles - v short term
- carbohydrates - immediate use (minutes or hours)
- adipose - long term
- muscle proteins - under extreme conditions
What is obesity?
Excessive fat accumulation in adipose tissue (BMI >30)
What can obesity lead to?
Cancer, cardiovascular disease, type II diabetes
What BMI ranges classifies as underweight?
<18.5
What BMI ranges classifies as desirable?
18.5 - 24.9
What BMI ranges classifies as overweight?
25 - 29.9
What BMI ranges classifies as obese?
30 - 34.9
What BMI ranges classifies as severely obese?
> 35
What can low protein intake result in?
- decrease in plasma oncotic presssure
- oedema
- kwashiorkor
