Diet And Food Production Flashcards
How an unbalanced diet can lead to malnutrition
Malnutrition is caused by an unbalanced diet.
Consuming above or below the recommended quantities of nutrients.
Can lead to deficiency diseases.
Obesity is caused by consuming too much energy and the excess energy is deposited as fat in the adipose tissues. Obesity is the condition in which excess fat deposition impairs health and it usually defined when a person has a BMI of 30 or over=body weight of 20% or more above the weight recommended for the height.
Discuss the links between diet and coronary heart disease
Excess salt in the diet decreases the water potential of the blood, more water is held in the blood and blood pressure increases. This can lead to hypertension, damages the inner lining of the arteries, one of the early steps in process of atherosclerosis Saturated fats (animal) can cause high blood cholesterol levels, increasing blood concentration of LDLs, possibly leading to atherosclerosis.
Obesity and diabetes increase the risk of CHD.
45-47% of deaths from cholesterol have been linked to high blood cholesterol levels
discuss the possible effects of a high blood cholesterol level on the heart and circulatory system, with reference to high-density lipoproteins (HDL) and low-density lipoprotein (LDL);
Cholesterol is transported around the body in the form of lipoproteins. Lipoproteins can be taken up by cells that have the correct receptor sites.
?High Density Lipoproteins
-A combination of unsaturated fats, cholesterol and protein.
-carry cholesterol from the body tissues to the liver, where the cholesterol is used to make bile or broken down.
-high levels of HDL are associated with reducing blood cholesterol levels.
-They can reduce deposition on the artery walls.
?Low Density Lipoproteins
-Produced by the combination of saturated fats, cholesterol and protein.
-carry cholesterol from the liver to the body tissues.
-A high blood concentration of LDLs cause dispositions on the artery walls.
-Saturated fats decrease LDL receptors activity
as the blood LDL concentration rises; less is removed from the blood,
higher concentrations of LDL in the blood, which are then deposited on the artery walls.
-Polyunsaturated and monounsaturated fats increase LDL receptor activity, so decrease concentration of LDL in blood
Why do humans need plants so much?
Plants are the basis of all food chains.
Plants can carry out photosynthesis to convert light energy to chemical energy.
Absorb CO2 from air to make carbohydrates.
Absorb minals from the soil and manufacture a range of other biological molecules.
Herbivores make use of these biological molecules when they eat and digest plants.
Humans eat both plants and animals (omnivores), gaining our nutrition both directly and indirectly.
How do we produce crops with high yields, disease resistance and pest resistance?
Selective breeding
- A pair of plants which display the desired characteristics are allowed to reproduce.
- offspring sorted carefully to select those with the best combination of characteristics and only those offspring are allowed to reproduce.
- careful selection and controlled reproduction continues for many generations,
- the required characteristic becomes more exaggerated.
How we produce domestic animals with high productivity
Selective breeding
A pair of animals which display the desired characteristics are allowed to reproduce.
The offspring produced are sorted carefully to select those with the best combination of characteristics and only those offspring are allowed to reproduce.
If this careful selection and controlled reproduction continues for many generations, the required characteristic becomes more exaggerated.
Describe how the use of fertilisers and pesticides with plants and the use of antibiotics with animals can increase food production
Fertilisers
Replace minerals in the soil which may have been removed by the previous crops. They contain Nitrate, Phosphate and Potassium. They increase the rate of growth and the overall size of crops
Pesticides
Kill organisms that cause diseases in crops. These organisms would reduce yield or kill the crop. Many crops are sprayed with fungicides to reduce fungal growth in the leaves or roots. Sheep are dipped to kill ticks.
Antibiotics
Infected animals can be treated with antibiotics to reduce the spread amongst animals that are intensively farmed in close proximity to each other. Such diseases could reduce the growth performance of the animals and may impair reproduction.
How can we make food production more efficient?
Plants Improve growth rate Increase yield size Reduce loss to disease and pests Standardise plant size, make harvesting easier Improve plant response to fertilisers
Animals
Improve growth rate
Increase productivity
Increase resistance to disease
Describe the advantages and disadvantages of using microorganisms to make food for human consumption
Advantages
- Production of protein can be faster than that of animal or plant protein
- Production can be increased or decreased according to demand
- No animal welfare issues
- They provide a good source of protein for vegetarians
- The protein contains no animal fat or cholesterol
- Single-cell protein production could be combined with removal of waste products
Disadvantages
- Many people may not want to eat fungal protein that has been grown on waste
- The microorganisms are grown in huge fermenters and protein needs to be isolated from the material on which microorganisms grow
- The protein has to be purified to ensure it is uncontaminated
- The conditions needed to grow the useful organisms are ideal for pathogenic organisms. Care needs to be taken to ensure that the culture is not infected
- The protein does not have the taste or texture of traditional protein sources, lacks palatability
How we prevent food spoilage by microorganisms
- Salting: Dehydrates any organisms as water leaves them by osmosis
-Adding sugar: Dehydrates any organisms as water leaves them by osmosis
-Heat treatment: Kills harmful organisms, denatures enzymes and other proteins
-Irradiation: Kills organisms by disrupting their DNA structure
Pickling: Acid pH denatures any microorganism’s proteins and enzymes - Freezing: Retards enzyme activity so their metabolism, growth and reproduction is slow, prevents uptake of water
Balanced diet
Contains all the nutrients required for health in appropriate proportions
(Carbohydrates, fats, proteins, water, vitamins and minerals, fibre)
What other health problems are linked to obesity?
Cancer Cardiovascular disease Type 2 diabetes Gallstones Osteoarthritis Hypertension (high blood pressure)
What things appear to be beneficial components of the diet, helping reduce the risk of CHD?
Dietary fibre,
Moderate alcohol consumption
Eating oily fish
What is CHD a result of (internally)?
Deposition of fatty substances in the walls of coronary arteries (atherosclerosis) which narrows the size of the lumen, restricting blood flow to the heart MUSCLE, causing oxygen starvation.
In which foods can you find different types of fats?
Saturated- animal fats
Unsaturated- plant oils, olive oil
