Session 3 Lecture 2-Nutrition,Diet And Body Weight Flashcards
(47 cards)
What is metabolism?
The chemical processes that occur within a living organism in order to maintain life.
4 types of pathways within metabolism
Oxidative pathways
Fuel storage and mobilisation pathways
Biosynthetic pathways
Detoxification pathways
What does oxidative pathway do?
Convert food into energy
What does fuel storage and mobilisation pathway do?
Allows fuel to be mobilised when we are not eating or need increased energy
What does biosynthetic pathways do ?
Produce basic building blocks for cells
What does detoxification pathways do?
Remove toxins
Definition of catabolic processes
Break down of big molecules into small molecules to release energy in the form of reducing power
Definition of anabolic processes
Use energy and raw materials to make larger molecules for growth and maintenance
Definition of energy
Defined as the capacity to do work
Why do living cells require energy ?
Biosynthetic work -synthesis of cellular components
Transport work -movement of ions and nutrients across membranes
Mechanical work -Muscle contraction
Electrical work-nervous conduction
What type of energy is used to drive energy requiring activities in the cells of the human body?
Chemical bond energy
Where is the chemical bond energy used in cells derive from and where is it stored ?
Derived from oxidation
Energy is conserved by formation of ATP from ADP and phosphate and the remainder is lost as heat
What is the official SI unit of food energy ?
Kilojoule
Converting kcal to kJ
1 kcal=4.2 kJ
List the essential components of the diet
Carbohydrates Proteins Fat Minerals Vitamins Water Fibre
CARBOHYDRATES
General formula for carbohydrates and what do they contain ?
(CH2O)n
Contain aldehyde(-C=OH) or keto(-C=0) group and multiple -OH groups
CARBOHYDRATES
Sugars are example of carbohydrates
Name 4 categories of sugar and what they mean
Monosaccharide - single sugar unit
Disaccharide - 2 units
Oligosaccharides - 3-12 units
Polysaccharides - 10-1000’s units
CARBOHYDRATES
List the major dietary carbohydrates (sugars )
- Starch (polymer of glucose)
- sucrose (glucose and fructose)
- lactose(galactose and glucose)
- fructose
- glucose
- maltose (glucose and glucose )
- Glycogen (polymer of glucose )
PROTEINS
What are proteins made up from ?
How many amino acids are used for protein synthesis in body ?
How many cannot be synthesised and must be obtained from diet ?
Composed of amino acids to form linear chains
20
9
PROTEINS
9 essential amino acids that cannot be synthesised and must be obtained form diet
If-Isoleucine
Learned -Lysine
This -Threonine
Huge -Histidine
List -Leucine
May - Methionine
Prove -Phenylalanine
Truly -Tryptophan
Valuable -Valine
FAT
What are lipids made of?
Triacylglycerols
3 fatty acids esterfied to one glycerol
FAT
3 types of fats
Saturated fat -solid at room temp-no double bond
Unsaturated fat - double bond - liquid at room temp
Trans fat- man made -double and no double bond
FAT
What is fat required for ?
Required for the absorption of the fat-soluble b vitamins (A, D,E and K) from the gut
Provides essential fatty acid e.g linoleic and linolenic acids which cannot be synthesised in body
MINERALS
What is their importance ?
Electrolytes establish ion gradients across membranes and maintain water balance.
Minerals such as calcium and phosphorus essential for structure
Also used as enzyme co factors
