diet and food Flashcards
1
Q
features of balanced diet
A
carbs proteins fat vitamins minerals water fibre
2
Q
malnutrition
A
unbalanced diet
obesity is a form, too much energy consumed
whic is depositted as fat in adipose tissues
BMI >30
3
Q
BMI
A
mass in KG / (height in m)2
4
Q
obesity leads too—>
A
cancer
cardiovascluar disease
type 2 diabetes
5
Q
obesity linked too
A
gallstones
ostearthritis
hihg b.p
6
Q
affect risks of CHD
A
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
7
Q
reduce risks of CHD
A
dietary fibre
moderate alcohol consumption
eating oily fish
8
Q
bad things –> increase risk
A
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
9
Q
cholesterol facts
A
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
10
Q
HDL;
A
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
11
Q
LDL;
A
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
12
Q
saturated, poly&monounsaturated affects on LDL receptors
A
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
13
Q
eating a lot of sat fats will ..
A
increase conc. of LDL in blood
14
Q
eating a low fat diet will..
A
reduce overall conc. of lipoproteins in blood
15
Q
eating high unsaturated will
A
increase HDL conc.
16
Q
eating mono and poly unsaturated ftas…
A
help to reduce LDL conc. in blood
17
Q
whats a herbivore ?
A
animals, make use of biologivcal molecules, when they eat and digest plant
18
Q
humans are…
A
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
19
Q
how can we make food production more efficient? for plants
A
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
20
Q
how can we make food production more efficient? for animals
A
improve rate of growth
increase productivity
increase resistance to disease
21
Q
selective breeding
A
gain desirbale traits 3 steps isolation artificial selection inbreeding/ linebreeding
22
Q
fertiliser, pesticides & antibiotics
A
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
23
Q
microorganisms and food;
A
microorganisms obtain nutrients by digesyting organic matter around them. they leave waste. organic matter they digest may be our food
24
Q
4 main ways microorganisms can spoil our food;
A
- 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
25
how do we prevent food spoilage?
quickly eat whilst still fresh
26
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
27
further food cautions
cannig , heat then seal
vacuum wrapping --> microbes cannot respire aerobically
any plastic / paper packaging
28
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.
29
quorn;
```
single celled protein
mycoprotein - made by fungus
produced early 1980s
meat substitute
no animal fat / cholesterol
```
30
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
31
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
32
health deifiniton
is a state of mental, physical and social wellbeing not just the absence of disease.
33
disease definition
a departure from good health caused by a malfunction of the mind or body
34
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
35
pathogens; def
organism that causes disease
| take nutrition fom host
36
wide range of organusms can cause dieases eg
bacteria, fungi , protostists, virsues
37
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
38
most common forms of transmission
by means of a vector
by physical contratcs
by droplets infection
39
transmission of malaria
caused by a eukaryotic organism from genus plasmodium
| spead by vector- female anopheles mosquito caiires the plasmodium from person - person
40
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
41
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.
42
HIV can be transmitted in the following ways:
```
echancged og body fluids sich as blood -blood contact
unprotected sex intercourse
unscreened blood transfusuins
use of unsetrilised surgical equiptment
sharing hypodermic needles
accidents sich as ' needle-stick'
across placenta or during childbirth
from mo t o baby during breastfeeding
```
43
TB; tuberculosis
is caused by bacterium, 2 speices, mycobacterium tuberculosis & M.Bovis. found in lungs. Tb is transmitted by droplet infection. inactive or controlled by immune system
by sneezes, coughs, talking, laughing. conditions meaning spread more easily; overcrowding
poor ventilation
poor health
poor diet
homelessness
living or working with people who have migrated form areas where TB is more common.
also transmitted in like and meat of cattle.
44
balanced diet definition
one that contains all nutrients required for health in appropriate proportions
45
malaria and world
kills 3 milllion eac year
can only be where Anopheles mosquito survives currently in tropical regions.
of all with lalaria 90% live in sub-saharan Africa.
but with global warming they may lead to europe and survive
46
HIV\AIDS, TB and world
worldwide disease, both values are rising
47
health organisations health organisations have limited resources so use...
epidemiology to study the spread of disease and factors affecting spread
48
primary defences definition
those that attempt to prevent pathogens from entering the body
49
immune response definition
specfifc response to a pathogen, which involves the eaction of lymphocytes and the production of antibodies
50
skin as a primary defence
outer layer = epidermis
most of the cells in epidermis are called keratinocytes
which are produced by mitosis at the base of the epidermis
migrte out to surface of the skin as they migrate they dry out and cytoplasm is replaxced with protein keratin, process is called keratinisation
by time cells reach surface theyre dead and slough off. keratinised cells act as an effective barrier for pathogens
51
mucous membrane as primary response
gasous exchange causes barrier between blood and envrinoment is reduced.
protected by mucous membranes. Epithelial layer has mucus secreting cells - goblet cells - also ciliated cells which waft mucus up airway o back of throat (top of trachea) where it can entre oesophagus.
swallowed and killed by acid in stomach pH of 1-2 denatures pathogens enzymes
52
other primary defences;
eyes and antibodies in tear fluid
ear canal lined with wax whic traps pathogens
vagina by maintaining relatively acidic conditions
53
2 types of phagocytes
neutrophils and macrophages
54
neutrophils phagocytes
most common, have multilobed nucleus.
manufactured in bone marrow
travel in the blood and often squeezed out in tissue fluid
found on epithelial surfaces ie lungs
shortlived, but released in large numbers
55
macrophages
larger cells manufactured in bone marrow
travel in blood as monocytes
settle in body organs, part,. lymph nodes where they develop into macrophages
also play important role in specific response to invading pathogens
56
how phagocytes work
engluf and destroy pathogenic cells
recognised as foreign by chemical markers on outer membrane called antigens (specififc to organissm)
proetins in blood - antibodies- attach to forgeing antigens . phagocytes have membrane bound receptors which bind to antibodies attached to antigen, process may be assisted by protein opsonins.
phagocyte will fold membrane inwards and trap pathogen in vacuoule caled phagosome. Lysosomes fuse with the phagosome and release enzymes into it. enzymes claled lysin and digest bacterium. end product = garmless nutrients which ae absorbed into cytoplasm.
57
role of macrophages
infected cells release chemicals ie histamine, which attract neutrophills. histamine also makes capillaries more leaky as a result more fluid leaves capillaries in the area of infection. causing swelling, and more tissue fluid moves into lymphatic systm. leading pathogens towards the macrophages waiting in lymph nodes. macrophages also play role in intitiating specific response to a disease. known as immune system, activation in the blood to help fight disease.
58
Antigen definition
molecules that stimulate an immune response
59
antibodies definiton
are protein molecules that can identity and neutralise antigens
60
antigens;
molecules which stimulate an immune response
any molecule can act as one
usually large molecules that have specific shape
foreign antigen is detected by immune system & stimulates production of antibodies,
antibodies and antigen are spicfic to eachother
antibody specific to pathogen
antigens usually protein, or glycoprotein in or on plasma membrne.
61
Antibodies
molecules produced by lymphocytes in ummune system
released in response to an infection
large proteins and also known as immunoglobulins
specific shape complimentary to that of antigen
one tyoe of antibody for every antigen that is detected
antibodies attach to antigens and render them harmless
62
structure f antibody;
Y shaped and 2 distinct regions
4 polypeptide chains held by disulfide bridges
constant region - same for all allows antibody to phagocytic cell.
variable region - specifics shape and complimentary to anitgen. result of amino acid sequence
hinge regions - allow certain degree of flexibility, alllows bracnhes of the y-shaped to move apart allowing binding of more than one antigen
63
how antibodies work
most work by attaching to the antigens on a pathogen. antigen may have other uses ie binding site to host cell which if antibody is attached to cannot be used, as it is blocked. CALLED NEUTRALISATION
some antibodies are larger than y-shaped molecule, resemble severeal y together, having many specific variable regions. each region can act as a binding site allowing to attach number of pathogens at once. CALLED AGGLUTINATION, when pathogens stuck together, cant enter host cell
64
producing antibodies
produced in response to infection
when 1st detected IS starts to produce antibodies. takes a few days before number is enough to combat infection known as primary immune response , once dealt with number of antibbodies drops rapidly
antibodies dont stay in blood
2nd time must be made again, a lot quicker secondary immune response
65
Cell signalling definition;
the communication between cells that allows effective coordination of a response
66
cel signalling;
immune resposne is specific to pathogens
cells must communicate - cell signalling
communication achieved through cell surface molecules & through release of hormone like chemical called cytokines.
in order to detetc a signal, the target cell must have a cell surface receptor. B cells & T cells have receptors that are complimentary in shape to the foreign antigen. the antigen may be an isolated protein, may be attached to pathogen or may be on surface of host cell. once detected, lymphocyte is activated or stimulated, chemiscal signlas are deteced by their target cells using specialised cell surface receptors.
67
sort of information is communicated ?
identifiation; done by pathogen, oathogen carries antigens on surface act as flags saying 'i am foreign' detected by our body cells
sending distress signals; when body cell is infected, usually damaged, internal cells will try to fight (lysosomes) as a result number of pathogen cels are damaged, parts of pathogen often end up attached to plasma membrane host, 2 afects;
act as distress signals and detected by body cells form immune system
also act as markrs to ssay host cell has been infected - T killer cells can recognise this and realise must be killed.
Antigen presentation; process been taken further by the macrophages in lymph nodes. macrophages act like phagocytes to enguld and digest pathogen. dont fully digest, sepreate antigens and creat cell surface molecule exposed onto surface of macrophages. known as ANTIGEN PRESENTING CELLS, function to find lymphocites which can neutralise particular antigen.
instructions;
range of cytokines released by cells, act as instructions target cells. act over short distnce at very low conentration. act by binding to specific membrane-bound receptors on target cells, alters cells behaviour through gene expression .
68
communication using cytokines;
macrophages release monokines that attract neutrophils
macrophages release monokines that can stimulate B cells to differentiate & release antibodies
T cells, B cells and macroohages release interleukins, whic can stimulate proliferation and differentioan of B & T Cells
many cells can release interferon, which can inhibit virus replication and stimulate the activity od T killer cels.
69
immune system;
a specific response to the detectio of pathogens.
ivolves B lymphocytes and T lymphocytes (white blood cells with a large nucleus and specialised receptor.
immune response produces antibodies (antibodies which neutralise foreign anitgens) long term protection, produces immunological memory through release of memory cells which stay in body for number of years
70
memory cells;
are cells that circulate in the blood after an immune response. The speed up the response to a subsequent attack by the same pathogen.
71
lymphocytes definition
are white blood cells that circulate around the body in the blood and lymph. B cells mature in the bone marrow, white T cells originate in the bone marrow but mature in the thymus gland
72
starting the response
an invading pathogen has foreign antigens. trigger immune response these must be detected by specific T cells and B cells . these lymphocytes carry correct receptor molecules on their membranes. receptor molecule= surface proteins which are complimentary to the shape of the antigen. Once the correct T or B lymphocytes detect antigens, response can begin.
however only a few correct T & B lymphocytes in body, may take time to find antigen. presentation of foreign antigens by a number of cells increase chances of finding. cells attacked by pathogen display antigenson srface membrane. MAcrophages in lymph system become anti-presenting cells.
73
selection of correct B AND T lymphocyte is known as?
clonal selection
74
before lymphocytes can become effective they must in crease in numbers known as...
clonal expansion- divide by mitosis number of times, theyre cloned
75
differentiation;
B & T cells dont maufacture antibodies directly. once selected T lymphocytes differentiate into 3 types and B lymphocytes into 2
76
t lymphocytes 3 differentioation types ;
T killer, kill already infected body cells
T memory
T helper, whi release cytokines to stimulate B lymphocytes devlop and phagocytosis by phagocytes
77
2 tyoes of B lymphocytes
plasma cells, flow around the body manufacturing and releasing Antibodies
B memory cells, stay in body for many years and as as the immunological memory
78
seoncadry invasion what ahppens?
immune response leaves memory cells in the body, invasion by same pathogen means simulation of plasma cells and antibodies is a lot quicker
79
Vaccination deifiniton
a deliberate exposure to antigenic material, which activates the immune system to make an immune response and provide immunity
80
vacination;
artificial immunity.
| result immune system manufactures antibodies and memory cells. memory cellls = long term imunity
81
antigenic material used in vaccines different froms;
whole, living ( usually less harmful ones) SMALL POX
a harmless version of the pathogenic organism MEASLES / TB
a dead pathogen CHOLERA VACINES
preparation f the antigens from a pathogen HEPATITIS B
some harmless toxins (toxoids) TETANUS
82
herd vaccination
provde immunity to all or most of people at risk. atleast 85% required to stop disease form spreading further
cities , countries etc
83
ring vaccination
vacciantion of when new disease reported, everyone in surrounding houses, or villages or towns. Cattle diseases
84
possible future threats;
pathogenic organisms can form new strain by mutation, meaning existing vaccines may have no or little affect on neew strain. Diseases by viruses = serious threat
85
Active and passive immuntiy ;
Active; achieved by activation of immune system
lymphocytes in the body manufacture antibodies and release them into blood
passive; provided by antibodies which have not been manufactured by stimulationg recipients response. Ie, fomr mother, breast milk or intravenous injection, often short lived
86
natural and artificial
natural; gained in the normal course of living processes, gained as infection
artificial; gains by deliberate exposure to antibodies or antigens
87
the need for new drugs
new diseases are emerging
there are still many dieases for which there are no effective treatments
some antibiotic treatmens are becoming less effective
88
how are new drugs discovered?
```
by accident
traditional medicine
anaesthetics
observation of wildlife
modern reasearch
```
89
cigarette smoke
contains over 4000 chemicals including; tar (mixture of chemicals including carcinogens), CO, nicotine
90
what harm doe tar cause? short term affects
settles in the lining of the airways & alveoli
increasing diffusion distance for O2 entering blood and for CO2 leaving
presence of many chemicals lying on surface of the airway may cause an allergic reaction. Causes smooth muscle in walls of the airways to contract. lumen of airways gets saller & restricts flow of air to alveoli.
tar paralyses cili and makes goblet cells larger and secrete more mucus . Bacteria trapped in mucus dont move and therefore higher chance of infection to lungs. combination of bacteria and mucus may eventually block bronchioles.
smokers more likely to cathch diseases
91
Tar and long term affects
smokers cough, attempt to shift bacteria- laden mucus that collects in the lungs. results from irritation of the airwats by the mucus & bacteria also need to clear airways in order for air to reach alveoli.
constans cough = own affects. delicate lining of airwats and alveoli are damaged and replacedd with scar tissue which is thicker and less flex. layer of smooth muscle in bronchiole walls thicken, reducing lumen of airway. flow of air perm. restricted.
frequenct infections because of mucus inflame linings of airway. damages lining (epithelium) attracts WBC, to deal with pathogenic microorgs. tthey release enzymes which digest parts of lining on the lungs in order to pass through air spaces. enzyme elastase, this damages elastic tissue in the linnig od the lungs. greatest effect in small bronchioles and aveoli. loss of elastic tissue = reduce elasticity in alveoli walls. During exhalationm alveoli walls dont recoil to push air out, bronchioles colapse, trapping air in the alveoli, can cause alveoli to burst as pressure in lungs increases.
92
Lung cancer;
cigarette smoke has lots of carcinogenic compounds - cause cancer
Benzopyrene is one of most harmful. compounds are in tar whicih lies on surface of lungs. Compounds enter lungs tissue, enter nucleus of cells and effect genetic material - mutation. affects genes, that control celldivision then uncontrollable cell division may take place. THIS IS CANCER. often starts at entrance to bronchi.
93
diseases associated with smoking?
chronic bronchitis; inflammation of the lining if the airways. This is accompanied by damage to cilia & overproduction of mucus.
emphysema; loss of elasticity in alveoli, causing them to burst. reducing SA of lungs. often short breathed.
Chronic obcstructive pulmonary disease; combination of diseases, chronic bronchitis, emphysema and asthma.
lung cancer; recognise by continual choughing and shortened of breath.
94
aatherosclerosis;
deposition of fatty substances in the walls of the arteries
95
cardiovascular disease;
disease of the heart or circulatory system
96
nicotine and carbon monoxide;
both ofund in cigarette smoke, they enter the lungs and pass through the lung surface in to the blood. in blood they cause changes to circulation.
97
Changes in circluation lead to increase risk to CHD including;
atherosclerosis
CHD
stroke
98
nicotine in lungs
causes ediction
nicotine mimics the action of transmitter substances at the synapse between nerves
causes the release of hormone adrenaline
causes constriction of the arterioles leading to exremeties of the body
also affects platelets making them sticky increasing risk of thrombus
99
CO in lungs
enters RBC and combines with haem and forms CARBOXYHAEMOGLOBIN.
CO also damages lining of arterues
100
problems caused by change in blood system
can cause CHD, CHD is a multifactural disease - many reasons to have it
101
Atherosclerosis
CO dmages inner lining of arteries
if Higher b.p adds to damage to linings
damage is repaired by action from WBC and PHAGOCYTOSIS - these encourage growth of smooth muscle and deposistion of fatty substances. deposits of atheromas may include platelets, firbes and dead blood cells. this build up occurs just under endothelium in wall of artery. may grow enough to break through artery forming plaque- stick outs into lumen. artery now rough and les flex and reduces size of lumen reducing blood flow.
102
Thrombosis
blood clots, where struggles to passs plaque. and bevause plateles are sticky, blood clot occur. block arteries, small break off and block smaller arteroes
103
CHD ( coronary heart disease)
coronary arteries branch off aorta cose to heart and carry blood at high pressure therefore are prone to damage and atherscleorosis. When lume of the coronary artery is narrowed by plaque, reduces Blood flow to heart muscle, receives less O2 for resp. leading to CHD which takes 3 forms; angina - pain in chest which may extend down left arm up to the neck
heart attack - death of part of heart muscle ususally caused by clot
heart failure- heart cannot sustain its pumping action can be due to blocking of main artery
104
stroke;
death of part of brain tissue, loss of blood flow to part of brain . suddenly
2 causes; burst artery leading to brain
blood clot in small artey leadin gto brain
