Week 9 Flashcards
What is an overview of food security?
Food security exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life. (FAO)
What are nutrients we get from food?
Macronutrients
Carbohydrates, proteins and fats – fuels and building blocks
Fibre – bowel health, satiation
Micronutrients
Essential amino acids, trace minerals, vitamins
Phytonutrients
Protective functions
What is an overview of carbohydrates?
Carbohydrates are sugars. They can exist as monomers like glucose and dimers like sucrose
Carbohydrates can also be long polymers.
Starch is a polymer of glucose joined with an alpha linkage. Cellulose is a polymer of glucose joined with a beta linkage.
What is an overview of Carbohydrate metabolism?
Every cell in your body uses glucose to produce energy (ATP)
Excess glucose stored as glycogen (short-term storage) or fat
What is an overview of carbohydrates digestion?
In your body, starch and sucrose are converted into glucose.
Mammals do not produce an enzyme that breaks the bonds in cellulose, so it is not absorbed but passes through the gut undigested
Some animals carry cellulose-digesting bacteria in their gut, but we don’t
What is an overview of amino acids?
Twenty amino acids comprise the universal building blocks of proteins
The nitrogen-containing amino group is an important feature of amino acids
The side chain, R, of an amino acid determines its chemical properties. Protein properties are specified their amino acid composition
What is an overview of protein metabolism?
Ingested proteins are broken down to amino acids, then recombined to form new proteins; e.g. muscle, red blood cells
What is an overview of protein assimilation?
Assimilation of amino acids into proteins
Excess amino acids can be used as an energy source, with nitrogen secreted in urine
What is an overview of Lipids- fats and oils?
Lipids are hydrocarbons, energy-rich compounds. Like gasoline, lipids release energy when oxidized.
Many animal-derived foods are high in fat
Oils are lipids extracted from plant seeds or fruits
What is an overview of Lipids- fats and oils storage?
Plants and animals store energy as lipids, and lipids are also normal components of every cell and the basis of the cell membranes. At room temperature, fats are solid and oils are liquid, but both are lipids
What is an overview of Fatty acids are saturated, monounsaturated or polyunsaturated?
Saturated fatty acid (SFA) – abundant in animal fats (meat and butterfat
Monounsaturated fatty acid (MUFA) – abundant in some oils (olive, canola)
Polyunsaturated fatty acid (PUFA) – abundant in some fish and seed oils (sunflower, soybean)
What is the difference between saturared and unsaturated fats?
Saturated all carbons are fully bonded
Unsaturated contain C=C double bond, mono means one and poly means multiple
What is an overview of total CO2 emiisions tons per ton of protein consumed?
Beef - 2400
Poultry - 300
Tubers - 100
Wheat - 80
What is an overview of total feshwater consumption (1,000m^3) per ton of protein consumed?
Beef - 110
Poultry - 30
Tubers - 25
Wheat - 18
What is an overview of total land use (ha) per ton of protein consumed?
Beef - 140
Poultry - 20
Tubers - 5
Wheat - 5
What fuels dietary dificineces?
Crop failures especially in vulnerable regions can lead to famines
War, conflict and corruption can interfere with food distribution
Poverty contributes to chronic malnutrition
What is an overview of children and dietary deficiencies?
Kwashiorkor cases found in Nigerian relief camps during the Nigerian-Biafran war.
Kwashiorkor is a disease brought on due to a severe dietary protein deficiency, and this child, whose diet fit such a deficiency profile, presented with symptoms including edema of legs and feet, light-colored, thinning hair, anemia, a pot-belly, and shiny skin
What is an overview of crop dependancies?
Many people survive on a very limited range or a single staple crop.
Nutritional enhancement in these cases is essential to provide essential vitamins and nutrients that may be low or absent in these staple foods.
What is an overview of vitamin A deficiency?
Vitamin A deficiency is a global health problem 100 million children are Vitamin A deficient primarily in Subsaharan africa and south Asia
Up to 500,000 children become blind every year and half of these die within 12 months of losing their sight
Improving dietary intake of carotenes can reduce child mortality by 25 %
What is the main reaction of beta-carotene?
Beta-carotene –> 2 x Retinal using O2 to break doube bond
Retinal is a retinoid with a efficient delivery of the most direct form of vitamin A molecules
What is an overview of Synthesis, storage and breakdown all affect β-carotene content?
To increase beta-carotene levels in plants, you need more synthesis, more storage or less catabolism
Stored in Chromoplasts – organelles that store carotenoids
Three reaction starting with geranylgeranyl pyrophosphate
What is an overview of Beta-carotene production?
Geranylgeranyl pyrophosphate –> Phyoene desaturase –> zeta-carotene –> Lycopene –> Beta carotene
What is an overview of vitamon A supply of golden rice?
32 fold increase in Beta-carotene with vitamin A levels being around 2.5 times greater than daily recommened
What is an overview of the application of golden rice?
The United States Food and Drug Administration (FDA) has approved Golden Rice, marking the third positive international assessment for the genetically engineered biofortified crop. Previously, Food Standards Australia, New Zealand and Health Canada gave Golden Rice the stamp of approval in February and March 2018