Nutrition, Diet and Body Weight Flashcards
What are the 4 Pathways of metabolism
- Oxidative pathways
Convert food into energy - Fuel storage & mobilisation pathways,
Allow fuel to be mobilised when we are not eating or need increased energy
3.Biosynthetic Pathways
Produce basic building blocks for cells
4.Detoxification Pathways
Remove toxins
What is a catabolic process
Catabolic processes:
Break down molecules to release energy in the form of reducing power
What is Anabolic processes
Anabolic processes:
Use energy & raw materials to make larger molecules for growth and maintenance
What do all living organisms need energy for (5)
- Biosynthetic work – synthesis of cellular components.
- Transport work – movement of ions & nutrients across membranes.
- Mechanical work – muscle contraction.
- Electrical work – nervous conduction.
- Osmotic work – kidney.
what form of energy do cells derive our energy from
Cells use Chemical bond energy to drive energy-requiring activities
What is oxidised for energy production
Energy production by oxidation of:
* Lipids
* Carbohydrates
* Protein
* Alcohol
What is the SI unit for Food energy
Kilojoule (kJ) is official SI unit of food energy
Which term for food energy is more commonly understood by patients
“calorie”
still in common use by physicians as better understood by patients.
What does 1 calorie , (1Kcal) equal
What is the conversion of Kcal to Kilojoules
1 Kcal = amount of energy needed to raise temperature of one kilogram of water by one degree Celsius
1 kcal = 4.2 Kilojoules
What are the Major Dietary Carbohydrates
- Starch (Carbohydrate storage molecule in plants. Polymer
of glucose) - Sucrose (Table sugar. Glucose-fructose disaccharide)
- Lactose (Milk sugar. Galactose-Glucose disaccharide)
- Fructose (Fruit sugar: Monosaccharide)
- Glucose (Predominant sugar in human blood)
- Maltose (Glucose-glucose disaccharide)
- Glycogen (Carbohydrate storage molecule in animals. Polymer of glucose)
Why is important to maintain plasma glucose levels
RBCs have no mitochondria,
thus cannot preform oxidative metabolism
This means its reliant in glycolysis from glucose to fuel RBC’s
If glucose drops below 2.8 milimolars
it can lead to a come.
How many different Amino Acids are used for Protein Synthesis
- 20 different amino acids used for protein synthesis in body
What are the 9 essential amino acids
9 Essential amino acids cannot be synthesised and must be obtained from diet
- Isoleucine
- Lysine
- Threonine
- Histidine
- Leucine
- Methionine
- Phenylalanine
- Tryptophan
- Valine
Why are proteins from plants considered low quality
Proteins of plant origin generally considered “lower quality” since most are deficient in one or more essential amino acids.
Therefore essential that vegetarian diet obtains protein from a wide variety of plant sources
What are Fats comprised of
Lipid composed of Triacylglycerols (3 fatty acids esterified to one glycerol.)
What are trans Fats
Trans fats are artificially produced, gives it a longer shelf life
Why does Fats yield more energy than carbs or proteins
Contain much less oxygen than carbohydrates or protein (i.e. more reduced so yields more energy when oxidised)
What are fats used for -3
Required for absorption of the fat-soluble vitamins
(A, D, E & K) from the gut.
Provides Energy (when oxidised)
Provides essential fatty acids
e.g. linoleic and linolenic acids which cannot be synthesised in body.