diet and food Flashcards
features of balanced diet
carbs proteins fat vitamins minerals water fibre
malnutrition
unbalanced diet
obesity is a form, too much energy consumed
whic is depositted as fat in adipose tissues
BMI >30
BMI
mass in KG / (height in m)2
obesity leads too—>
cancer
cardiovascluar disease
type 2 diabetes
obesity linked too
gallstones
ostearthritis
hihg b.p
affect risks of CHD
result of deposition of fatty substances in the walls of coronry arteries. deposition known as atherosclerosis depostiion narrows lumen in arteries restricting blood flow --> heart may cause O2 starvation
reduce risks of CHD
dietary fibre
moderate alcohol consumption
eating oily fish
bad things –> increase risk
salt - excess, decreases w.p of blood. more water in blood increasing pressure can cause hypertension.
Fats (lipids) = saturated = more damage ( from animals)
unsaturated - plant oils
polyunsatutared and monosaturated are highly beneficial to diet.
Cholesterol –> not a triglyceride but similar properties. Made in liver from saturated fats, associated with s.fats. Too much is harmful, high blood cholesterol conc. have been linked to 45.47% of deaths from CHD conc. should be below 5.2mmoldm-3
cholesterol facts
is a fat
essential to normal bodily functions
found in cell membranes & skin
used to make bile and steroid sex hormones therefore must be transported around the body
not soluble
tansported in blood in form of lipoproteins
liporoteins = tiny balls of fat & protein
HDL & LDL
HDL;
combination of unsaturated fats, cholesterol & protein
carry from body –> liver
liver receptor sites allowing HDL to bind to cell surface membranes
in liver cholesterol used in cell metabolism or broken down
reduce blood cholesterol levels at high levels
reduce deposition in arteriole walls
LDL;
sats, fats, cholesterol & proteins
cholesterol liver –>tissues
tissue cells have been receptor sites that allow LDL to bind to
high blood concentration of LDL’s cause depostion on artery walls
saturated, poly&monounsaturated affects on LDL receptors
saturated fats decrease activity of LDL receptors. meaning less is removed = higher conc. of LDL in blood
poly & monounsaturated ; increase activity of LDL receptors reducing conc. in blood
eating a lot of sat fats will ..
increase conc. of LDL in blood
eating a low fat diet will..
reduce overall conc. of lipoproteins in blood
eating high unsaturated will
increase HDL conc.
eating mono and poly unsaturated ftas…
help to reduce LDL conc. in blood
whats a herbivore ?
animals, make use of biologivcal molecules, when they eat and digest plant
humans are…
omnivores. both plant and animals
gain nutrients directly from plants and indirectly by eating herbivorous animals. humans = short food chain
to mae food chain more efficicient we increase food production
how can we make food production more efficient? for plants
improve the growth rate of crops
increase size of yield from each plant reduce losses of crops due to disease and pests
make harvesting easier by standardisising plant size
improve plant responses to fertilisers
how can we make food production more efficient? for animals
improve rate of growth
increase productivity
increase resistance to disease
selective breeding
gain desirbale traits 3 steps isolation artificial selection inbreeding/ linebreeding
fertiliser, pesticides & antibiotics
f= replace minerals in soil 9 nitrates, phosphate and potassium) p= kill organisms that cause disease in crops a= treat infected animals, reduce spread of disease
microorganisms and food;
microorganisms obtain nutrients by digesyting organic matter around them. they leave waste. organic matter they digest may be our food
4 main ways microorganisms can spoil our food;
- visisble growth of microorg on our food
- microorg use an ecternal digestion process ( release enzymes)
- bacterium ckostidium botluinum produces a toxin called botulin. cuasing botulin.
- prescence of microorg in food can cause infection ie. salmonella
how do we prevent food spoilage?
quickly eat whilst still fresh
treatment to kill / prevent growth of microrg
cooking - heat denatures enzymes & other proteins & kills the mircroorgs
pasteurising - heatingto 72 degrees, for 15 secs then cooling to 4 degrees killing harmful microorgs.
smoking- fiid develops hardeneds, dry outer surface & smoke contains anitbacterial chemicals
pickling- use an acid pH to kill microorgs by disrupting their DNA structure
cooking and freezing - do not kill, but retard enzyme activity
further food cautions
cannig , heat then seal
vacuum wrapping –> microbes cannot respire aerobically
any plastic / paper packaging
make food using microorgs?
eg; alcohol; - anaerobic respiration of yeast. cereal grains containing sugar maltose used to brew beers as yeast respires in sugar. Grapse contain the sugars fructose and glucose which yeast uses in making wine.
quorn;
single celled protein mycoprotein - made by fungus produced early 1980s meat substitute no animal fat / cholesterol
advatages of making food with microorgs
production of protein can be made many times faster than that of animal or plant
production cna be increased and decreased according to demad
no animal welfare issues
good source of protein for veggies
SCP production could be combined with removal of wate products
no animal fat / cholesterol
disadvantages of food made from microorgs;
people may not want to eat fungal protein. food that has been grown on watse
isolation of the protein - microorgs are grown in huge fermemeters and need to be isolated
protein has to be purified to ensure it is not contaimitated
infection
palatability - texture and taste
health deifiniton
is a state of mental, physical and social wellbeing not just the absence of disease.
disease definition
a departure from good health caused by a malfunction of the mind or body
paprasite definiton
an organsism that lives on or in a living thing causing harm to its host.
internal / external
damage to host by tkaing nutrition
pathogens; def
organism that causes disease
take nutrition fom host
wide range of organusms can cause dieases eg
bacteria, fungi , protostists, virsues
transmission of malaria aids/hiv & TB oathogen must be able to
travel from one host to another
get into host tissue
reproduce
cause damage to host tissue
most common forms of transmission
by means of a vector
by physical contratcs
by droplets infection
transmission of malaria
caused by a eukaryotic organism from genus plasmodium
spead by vector- female anopheles mosquito caiires the plasmodium from person - person
malaria cycle;
if the host already has malaria, mosquito suck parasite gametes into its stomach
gametes fuse and zygotes develop in the mosquitos stomach
infective stages are formed and these move to the mosquitos salivary glands
this saliva contains infective stage of aprasite
once in host,umans, enter liver and reproduce
then travle to blood stream and entre RBC where gametes are produced
also can be passed via placenta, unscreened blood transfusion and unsterilised needles etc
transmission of HIV AND AIDS
cuased by human immundeficiency virus.
enter body but can remain inactive, known as HIV positive.
Once virus becomes active it attack T helper cells in immune system
if theyre destroyed ability to resist infection is reduced, may contract a range of opportunitic infections. AIDS; accquired deficiency syndrome.