Nutrition Flashcards
What are the 3 main uses of food molecules absorbed by the GI tract?
- to supply energy for sustaining life processes
- serve as building blocks for synthesis of more complex molecules e.g muscle proteins, hormones, enzymes
- storage for future use
What are nutrients?
chemical substances in food that body cells use for growth, maintenance and repair
What are the 6 main types of nutrients?
-carbohydrates
-lipids
-proteins
-water
-minerals
-vitamins
What are essential nutrients?
specific nutrient molecules that the body can’t make and must be obtained from the diet
What elements do all carbohydrates contain?
-carbon
-hydrogen
-oxygen
Give examples of both simple sugars and complex sugars
-simple= glucose, fructose
-complex= starch, glycogen, cellulose
What are the main functions of carbohydrates?
-energy
-energy storage
-principle component of dietary fibre
What is glycogenesis?
the synthesis of glycogen from glucose
What is glycogenolysis?
the breakdown of glycogen to glucose
What elements do all proteins contain?
-carbon
-hydrogen
-oxygen
-nitrogen
-sulphur
these form amino acids
What are the main functions of proteins
-structural= growth and repair
-functional= enzymes, hormones
-energy in starvation state
What elements do all lipids contain?
-carbon
-hydrogen
-oxygen
-phosphorus
-nitrogen
What types of lipids are there?
-fatty acids
-triglycerides
-cholestrols
-phospholipids
What are the main functions of lipids?
-energy storage
-insulation
-protection
-cell membranes
-steroid hormones
-bile
-local acting hormones
What units are dietary energy measured in?
-kilojoules (Kj, SI unit)
-kilocalories (Kcal)
What factors does different energy requirements depend on?
-age
-growth and development
-activity
-gender
-pregnancy/ lactation
How is formula milk different from cows milk?
its a specially modified cows milk:
-less protein
-less saturated fats and increased unsaturated fat
-less sodium and calcium
-more lactose
-more micronutrients
What is weaning?
the process of introducing solid foods to babies, happens around 6 months as nutrient stores will fall if continue to be exclusively breast fed
What’s the formula for body mass index?
weight (kg) divided by height (m)
What are the possible nutrient deficiencies with vegetarianism?
-iron deficiency anaemia
-energy
-calcium and other minerals
-vitamin B12 and D
What are the possible benefits of vegetarianism?
-increased intake of dietary fibre
-increased intake of fruit and veg
-reduced intake of saturated fat
What are the 2 sources of cholesterol in the body?
- some are present in foods
- most synthesised by liver cells
What are the 2 ways that fatty foods with no cholesterol can still increase blood cholesterol?
- an increase in dietary fat stimulates reabsorption of cholesterol containing bile back into the blood, therefore less cholesterol is lost in faeces
- when saturated fats are broken down in the body, liver cells use some of the breakdown products to make cholesterol
What does a lipid profile measure?
-total cholesterol (TC)
-HDL cholesterol
-VLDL’s
What increases the risk of Coronary Artery Disease?
Total cholesterol
What treatments are there for reducing blood cholesterol?
-diet modifications
-exercise
-drugs e.g statins
What is metabolism?
-refers to all chemical reactions in the body
-an energy balancing act between anabolic and catabolic reactions
What are anabolic and catabolic reactions?
Anabolic= reactions that combine simple substances into more complex molecules
Catabolic= reactions that break down complex organic compounds into simple ones
What are enzymes?
biological catalysts that speed up the rate of chemical reactions
What is the role of ATP in linking anabolic and catabolic reactions?
-in anabolic reactions energy is transferred from ATP to complex molecules (glycogen, proteins, triglycerides), releasing heat
-in catabolic reactions energy is transferred from the complex molecules to ATP forming simple molecules (glucose, amino acids, glycerol), releasing heat
how are carbohydrates metabolised?
-during digestion disaccharides are converted to glucose
-some glucose is catabolised by cells to produce ATP
-excess glucose is stored by the liver as glycogen
What is cellular respiration?
the catabolism of glucose to produce ATP, involving glycolysis, the Krebs cycle, and the electron transport chain
How are lipids metabolised?
-muscle, liver and adipose cells catabolize fatty acids from triglycerides to produce ATP, through lipolysis
How are proteins metabolised?
-during digestion, proteins are broken down into amino acids
-these are then oxidised to produce ATP or use to make new proteins for growth and repair
-excess amino acids are converted into glucose or triglycerides
What are the functions of proteins?
-enzymes
-transportation
-antibodies
-clotting factors
-hormones
-actin and myosin in muscles
-structural body components
