F212 Diet And Food Production Flashcards
What affects the diet a person needs?
Age
Gender
Metabolic Rate
Level of Physical Activity
Balanced Diet
Definition
A diet which contains all of the nutrients required for health in the appropriate proportions for health
Diet
Carbohydrates
The majority of your energy intake
Primary / immediate energy source
Diet
Proteins
Minor energy source
Needed for growth and repair
Diet
Fats
Major energy store Used for: -Insulation -Cell membranes -Hormones -Cholesterol
Diet
Fibre
Indigestible
Essential for ensuring normal function of the digestive system
Diet
Water
Essential for function
Important transport medium
Directly involved in some metabolic reactions
Diet
Vitamins
Important role in the chemical processes takin place inside cells
Diet
Minerals
Inorganic elements essential for normal function
Nutrition
Definition
Nourishment, the nutrients and energy needed for health
Malnutrition
Definition
A health condition caused by an unbalanced diet
Obesity
Definition
When a person is 20% or more over the recommended weight for their height
Body Mass Index
Equation
BMI = mass (kg) / height² (m)
Obesity
Cause
Obesity is caused by consuming an excess of energy from carbohydrates, proteins and fats that the body doesn’t need
Fat is deposited in the adipose tissues
For someone with obesity these deposits have become excessive and impair health
Obesity
Health Risks
Cancer Cardiovascular Disease Type 2 Diabetes Gallstones Osteoarthritis Hypertension
Coronary Heart Disease (CHD)
What is it?
Myocardial Infarction - heart attack
Angina - chest pain
Heart Failure - heart stops beating
Diet
Coronary Heart Disease
Excess salt decreases the water potential of the blood so more water moves into the blood from the cells by osmosis causing hypertension
Excess of saturated fat increases the concentration of low density lipoproteins in the blood contributing to atherosclerosis
Cholesterol is associated with many saturated fats and oils and having too much in the blood is harmful
High Density Lipoproteins
Carry cholesterol from body tissue back to the liver where it is broken down to be used in metabolic processes
Low Density Lipoproteins
Carry cholesterol from the lover and by d to body tissue cells where they deposit the cholesterol
This contributes to atherosclerosis
Lipoprotein
Function
Used to transport lipids around the blood stream
Lipoprotein
Structure
The outside is formed from protein and a phospholipid layer
Inside this layer are the cholesterol and fatty acid that the phospholipid is carrying
Cholesterol
Made in the liver from saturated fats
A lipid molecule found in all cell membranes
Involved in the synthesis of steroid hormones
Plants and the Food Chain
Plants are the basis of all food chains
They are able to use photosynthesis to convert light energy into a stored chemical form
Humans depend on plants for food
Selective Breeding
Plants
Select two plants with desirable characteristics
Breed them together
Select offspring with desirable characteristics
Repeat over many generations
This can be used to produce plants with higher yield, disease resistance and pest resistance
Selective Breeding
Animals
Select a pair of animals with desirable characteristics Isolate them Interbreed Select offspring Repeat over me any generations
This ça be used to domestic animals and produce animals with high productivity
Efficient Food Production
Plants
Increase growth rate Increase yield Increase resistance to disease Improve fertiliser response Standardise crop size to make harvesting easier
Efficient Food Production
Animals
Improve growth rate
Increase productivity
Increase disease resistance
Food Production and Chemicals
Plants
Fertilisers
Pesticides
Fungicides
Food Production and Chemical
Animals
Antibiotics
Fertilisers
Definition
Chemicals that replace minerals in he soil which may have been used up by previous crops
Pesticides
Definition
Chemicals used to kill pests that cause diseases in crops
Can be used to stop disease spreading
Fungicides
Definition
Chemicals that reduce fungal growth on roots and leaves
Can be used to stop disease from spreading
Antibiotics
Definition
Treat infections and diseases in animals
Used to stop disease from spreading
Marker Assisted Selection
A section of complimentary DNA a is tagged
This binds to the desired gene in the target organism if it is present
This allows selection to take place at a much earlier stage
Microorganisms and Food Spoilage
Function of Microorganisms
Microorganisms obtain nutrition by digesting organic matter around them and leaving waste behind them
Microorganisms and Food Spoilage
Stages
Growth of microorganisms on food
Microorganisms secrete digestive enzymes to break down the food and then absorb the nutrients
Some microorganisms produce toxins that can kill humans
The presence of some microorganisms can cause infection
When is food described as spoilt?
When the effect of microorganisms becomes noticeable
Food Production and Microorganisms
Microorganisms can be used to make food e.g. milk, cheese, bread
Single cell proteins and myco proteins are artificial proteins produced by microorganisms
Food Production Using Microorganisms
Advantages
Production is faster No animal welfare issues No animal fat or cholesterol in the food Suitable for vegetarians Production can easily be varied according to demand
Food Production Using Microorganisms
Disadvantages
The protein has to be purified
Conditions for growing are also ideal for infection
Fungal protein doesn’t have the same taste or texture as animal protein
The microorganism has to be isolated from the protein it produces
Many people wouldn’t want to eat fungal protein
Methods of Preventing Food Spoilage
Cooking Pasteurising Salting Pickling Irradiation Freezing
Methods of Preventing Food Spoilage
Cooking
Denatures enzymes destroying the microorganism
Methods of Preventing Food Spoilage
Pasteurising
Heated to 72°C for 15°C seconds then cooled to 4
This kills microorganisms
Methods of Preventing Food Spoilage
Salting
Dehydrates the microorganism by causing water to leave by osmosis
Methods of Preventing Food Spoilage
Pickling
Acidic pH destroys proteins and enzymes destroying the microorganism
Methods of Preventing Food Spoilage
Irradiation
Ionising radiation disrupts DNA
Destroys microorganisms
Methods of Preventing Food Spoilage
Freezing
Causes the microorganism to become dormant but doesn’t destroy it
If the food is heated up again the microorganism can multiply
