Biology (Diet and Food production) Flashcards
A balanced diet is one which has?
all nutriendts required in proportionate amounts
What are the different componetns of a balanced diet and what do they do- carbohydrates, fats, proteins?
carbohydrates- main source of energy (simple- starch/complex-sugars/bread-indigestible fibre-provides roughagfe)
proteins- essential for growth/repair of tissues
fats- used in cell membrane (phosolipid bilayer)- sepeate cell contents from external envronemt, allow diffusion of substances
what are the ourpose of minerals, vitamins, water and fibres
The lack of what mineral can cause anaemia?
minerals- inorganic compounds essential for bodiyl functions
vitamins- used in metabolic processes e.g vitamin C- citrus fruits- help immune sytem fight infections
water- essnetial for bodily functions and to transport substances around body
fibres- essnetial for digestive system to functione.g roughagfe ti seed up passage of food
The mineral iron which means the body is unable to produce sufficent protein
what is malnurtition?
cause of an unbalcned diet
- too much food
- too luittle food
What is the most common form of malnutrition in the western [developing world]?
health risks i leads to?
obesity
cardiovascualr disease
type 2 diabetes- body becomes insensitive to insulin
gallstones- bile stored in gall bladder
high blood pressure- hypertension in blood
What are the causes of obesity?
- lack of exercise
- high consumption of fatty foods/salt
- more energy taken in than expanded by body
- low metabolic rate [genetic]- means slow rate of chemical reactions in body
Obesitty can lead to CHD- what decreases the chance of this?
- dietary fibres
- moderate alcohol consumption
- oily fish
What increases the risk of CHD and why? [ 2 main thngs]?
1) High salt intake>decreases water potential of cells.more moves in to RBC>increases blood pressure>cause hypertension
[where the blood pressure and diastotle pressure of heart {when its relaxing] is too high>can cause damage to inner lining of artery (atherosclerosis]
2) Both high levels of saturated fats [lipids] and cholesterol would mean more chance of LDL’s meanign more fatty deposits>increased risk of atherosclerosis.
For humans plants are?
completely dependant as they are the basis of all food chains>therefore plants are essential as they produce food from photsynthis rather than consumption
Selective breeding:
humans breed derirable charactersitics of an organism to make production more efficent
In plant you can make production more efficnet by?
- increasign yeidl size
- increasing growth rate
- increasng resitance to pests/disease
- improve plant repsosnes to fertilsiers
- standaring plant rise (make harvestign easier)
In animals you can improve?
- rsistance to infection/disease
- increase rate of growth
- increase productivity/yield
selective breeding example: tomatoes?
yellow leaf curl virus is devastative to tomatoes
wild tomatoe variet humans found that has evolved a resitance to it
allelue that is resposnible for the resistance
bred into domestic vairety
Selective breeding can be used to make domestic variety with?
hgih productivity
Selective breeding stages?- Isolation
1) Isolation- orgasnims ar selcted that contain desirbale characterisitics e.g. a cow with high meat prodiction and a huge one [same species]
select the pair that express the strongest genes [1 cow from each isolated pool]
Only these are allowed to breed (1st generatyion)
Artifiial selection stage?
2) The offspring produced are sorted carefully and those with the best combinations of the 2 characterisitcs are selected
Interbreedign stage?
3) Only hose selected with the best combinaion are allowed to reproduce
Over time, this selective process can result in the characterisitics being exaggerated
Modern breeding programmes?
keep detailed records- to prove ancestory of individuals
they apply selection pressure rath than allow natural selection to occur naturally
Fertilisers are used to?
-nirtrates/potassium
-minerals that replace inorganic ions in soil which have been removed/absobed by other plant crops
increase growth rate/overall size of plants
Howver, they’re expensive so are onyl used when outweigh cost of buying and applying
Pesticides are?
-kill organsim that cause disease
-insecides/fungicides that kill orgaisnms that would reduce yield/impair reprouduction
e.g. fungicides are used to stop fungal growht in leaves
howver, they are expensive but also more resitantt/stronger pathogns may survive blast and devlop a reistant strain that they pass onto osspring.
Antibiotics are use?
to kill bacteria without harming the whole organism
- they kill bacteria that wouild reduce growth rate/impari reporduction so they reduce spread of diseases especially amoing intensively farmed animal
Howver, issue of resistance to antibiotics- so discouraged except for a cure fo disease and limtied use encouraged
shouldn’t be used in case if no disease as his could eaisyl rise in a resistant strain
what are the 4 main ways bacteria can spoil food?
external digestion- turn it to mush
- visible growht on food
- release toxins
- cause infection
Salting/addign sugar?
decreases wat potential in food cells>water moves out of micro-organsim cells though osmosis>dehydrates cells.die
Freezing?
slows down enzyem activty- so slower in metabolsim, reproduction and growth
Heat Treament/cooking?
hgih heat termeoratuees>distorts 3D tertiary strucutre>denatures enzymes,die
Irradiation?
ionisaing radiation to distort 3D tertiary strucure>enzymes denature>die
Pickling?
acid/low pH to disrupt binds in tertiary 3D strucure>denature enzymes>cells die
adavantages of using mycoprotein?
- no animal welfare issues
-no animal fats/cholersterol used
-faster- more efficent
higher proudciton of protein
more energy-efficent- more enrgy beign onserved in food chain
Disadvantages of using mycoprotein?
- people dislike the idea of eating ‘fungal food’
-Micro-organism have to be isolated from protein they grow on (huge seperate fermenters- cost?) - cost of purifying protein
-risk of infection- ideal conditons for micro-organisms also result in ideal cnditons for pathogens
Platability- taste/texture isn’t the same
BMR?
indiviual is lying down
too many amino acids in diet
holocaust
Basal Metabolic Rate- minimum required enrgy to keep us alive- usually recorded by heat/oxygen lost
studies when a n individual is lying dow, warm after fasting for 12 hours
after holocaust- malnurtitioned prisoners0 showed too rich a protein diet caused harm
too many amino acids>loweed osomotic water potential>(blood full of fats/amino aicds)>water moves out- dehydrates the body
what thigns affect BMR? gender- age- prenacy- BDI-
men have increased
infants have higher
increases with prwegancy
increases with BDI
Most people for DRV have?
peak- middle of two extremes of LRNI and RNI
Some people have increased DVR's? pregancy age gender exerecise
atheltes- need more energy- use more up in repsriation
age- need more protein until certain age
gender-men generalyl need mor than women
Pregnancy- 1st 3 months- feottus needs a lot of protein
Problems with measuring DVR’s?
obtasianing figures for one age group?
measuring BMR is diffcult
religious ethical differences infleucne diet
grwoth rates/exercise
Advantage sof modern farming?
increased yeild (fertilisers)
increased gorwth rate
increased reistiance to pests (insecidices)
selective breeding - GM crops/anuimals e.g. cows with larf=ge size + hgih milk priduction (essential mineral ions)-
meat-essential amino acids
keep up with popualtion growth (globally increasing)
efficent/quick
Disadvantages of modern farming?
chemicla fertilsiers to increase yeild- damage ecosystem
soil erosion, salisantion, loss of land, increased diseases
equipment is expensive, hgih fuel (diesal consumoption)
welfare of animals- cows, chickens- minimsie movement to conserve energy
