bio - communicable & non communicable diseases Flashcards
Pathogen
microorganisms that cause infectious diseases
relies on their host to provide the conditions they need to grow and reproduce
Bacteria
Not all bacteria is bad
some are pathogens & cause diseases
Can be spread by: ingesting contaminated food, preparing food in unhygienic conditions, sexual contact
Antibiotics are becoming useless against bacteria as bacteria learns how to beat them by sharing their plasmids
Viruses
Very small pathogens - not living cells
has a strand of genetic material inside a protein coat - this replicates inside host cells to make new viruses
Plant defence responses
Physical - barriers e.g., Tough waxy cuticle around upper leaf, layer of dead cells around stem, cell wall
Mechanical thorns & hairs – prevents insects
Chemical - use of chemicals to attract or repel certain animals/organisms
Protists
Single celled eukaryotic microorganisms
Smoking
Chemical Carcinogens in cigarettes increase the chance of lung cancer.
Damages lining of arteries leading to atheroma build-up and a heart attack + stroke.
COPD - Chronic Obstructor Pulmonary Disease as smoking destroys many alveoli, so airways become inflamed & mucus builds up → patient become breathless.
Alcohol
Damages liver
yellow eyes
drowsiness
vomiting blood
alcoholic hepatitis
cirrhosis of the liver
alcoholism increases. treatment costs from the NHS
Diet
Bad diet leads to type 2 diabetes
Balanced diet + lack of highly processed foods → less chance of cardiovascular diseases or type 2 diabetes
Obesity leads to high blood pressure & build deposits up of fatty deposits leading to cardiovascular disease
Smoking (leads to)
Lung disease, cancer
Low birth weight & premature birth
Alcohol (leads to)
Liver & brain damage
Abnormal foetal brain development
Obesity (leads to)
Type 2 diabetes
Poor diet, smoking & no exercise (leads to)
Cardiovascular disease
Carcinogens & radiation (leads to)
Cancer
Health
state of physical and mental well-being
Measles
Type - Virus
cause - Droplet infection
Symptoms - Itching, fever
Cure - Vaccination
HIV
Type - Virus
cause - direct contact bodily fluids
Symptoms - AIDS, weak immune system
Cure - antiretroviral drugs prevent virus from replicating
Salmonella
Type - Bacteria
cause - food and contaminated utensils
Symptoms - stomach aches, vomiting, diarrhoea
Cure -Vaccinating animals / hygienic food prep
Gorrhoea
Type - Bacteria
cause - unprotected sex
Symptoms - pain in urinating, discharge from genitals
Cure - Barrier contraception, antibiotics
Tobacco mosaic Virus (TMV)
Type - Virus
cause - Get through wounds in the plant
Symptoms -Reduced photosynthesis, discoloured leaves, stunted growth
Cure - removing infected part of plant
Aphid infection
Type - Virus
cause - aphids greenflies are vectors
Symptoms - Stunted growth, yellow leaves
Cure - Insecticides & Natural predators of vector e.g. ladybird
how cancer happens
How is malaria transmitted
lifecycle of mosquitos
Phagocytosis
Phagocytes engulf pathogens by phagocytosis. by then the pathogen is engulfed and enclosed in a vacuum and digestive enzymes are secreted. the enzyme kills and digests the pathogen.
Lymphocytes - antibodies
Lymphocytes are white blood cells. Lymphocytes recognise only one type of antigen and binds to it once it comes into close proximity. They can also produce antibodies specific in shape to the antigens of that pathogen. It takes multiple days to find the correct shape, in which time illness is felt. So, they release the antibodies into the blood. These antibodies are going to bind to the antigens of that pathogen causing the pathogens to clump together making it more vulnerable to phagocytosis & the antibodies will kill the pathogens.
specific antibodies shape
Just like enzymes the antibody binds to specific antigens because the shape of the antigen is complementary to the shape of the antigen binding site.
immune response to disease exposure
1) After exposure, lots of different lymphocytes attempt to make antibodies that recognise antigens on the pathogen.
2) once an antibody binds correctly, the lymphocyte differentiates to make plasma cells and memory cells.
3) The plasma cells produce antibodies and help the phagocytes fight off the infection.
4) once the pathogen is defeated, the plasma cells die but the memory cells remain.
5) Reinfection is instantly recognised by memory cells which quickly produce lots of plasma cells.
how are monoclonal antibodies made
1) Inject mouse with chosen antigen that you want to produce antibodies for
2) The mouse’s lymphocytes are now going to produce specific antibodies for that antigen.
3) Remove the lymphocytes from the mouse. This lymphocyte produces the antibodies that you want to make the monoclonal antibodies from. So even though this lymphocyte can produce antibodies, it can’t divide.
4) Fuse the lymphocyte with a cancer cell (a tumour cell). The tumour cell can’t produce antibodies, but it can divide incredibly rapidly by mitosis. This forms a hybridoma which can divide incredibly rapidly producing many monoclonal antibodies, which are all specific to the same antigen.
use of monoclonal antibodies in pregnanacy tests
test stick and if pregnant
monoclonal antibodies are used in pregnancy tests. A hormone called HCG (human chorionic gonadotropin ) is found in the urine of women only when they are pregnant. Pregnancy testing sticks use monoclonal antibodies to detect this hormone.
Here’s how they work:
The test stick
The bit of the stick you wee on has some antibodies to the hormone, with blue beads attached. The test strip (the bit of the stick that turns blue if you’re pregnant) has some more antibodies to the hormone stuck onto it (so that they can’t move).
If you’re pregnant
If you’re pregnant and you wee on the stick, the hormone binds to the antibodies on the blue beads. The urine moves up the stick, carrying the hormone and the beads. The beads and hormone bind to the antibodies on the strip. So the blue beads get stuck on the strip, turning it blue.
role of monoclonal antibodies in cancer treatment
chemotherapy drugs kill all cells, but particularly fast-growing cells like cancer cells. This unfortunately includes other cells like hair, skin and intestinal cells resulting in hair loss, cracked skin and digestive problems. However, mAbs targets cancer cells while leaving healthy cells unaffected and they also target the toxic drugs to specific places in the body reducing the number of accidental cell deaths.
e.g. herceptin stops breast cancer cell growth
role of monoclonal antibodies in treating a disease
Treating diseases
Different cells in the body have different antigens on their cell surface. So you can make monoclonal antibodies that will bind to specific cells in the body (e.g. just liver cells). Cancer cells have antigens on their cell membranes that aren’t found on normal body cells. They’re called tumour markers. In the lab, you can make monoclonal antibodies that will bind to these tumour markers.
An anti-cancer drug can be attached to these monoclonal antibodies. This might be a radioactive substance, a toxic drug or a chemical which stops cancer cells growing and dividing. The antibodies are given to the patient through a drip. The antibodies target specific cells (the cancer cells) because they only bind to the tumour markers. The drug kills the cancer cells but doesn’t kill any normal body cells near the tumour.
use of monoclonal antibodies in pregnanacy tests
if not pregnant
If you’re not pregnant and you wee on the stick, the urine still moves up the stick, carrying the blue bead But ove’s thing to stick the blue beads onto the test strip, so it doesn’t go blue,
Control window
Pregnancy tests also have a control window. This shows the person using the test whether the test has worked conecth. The control window contains antibodies to the antibodies that are attached to the blue beads. This means that once the blue beads reach the control window, the antibodies attached to them will bind to the antibodies stuck to the control window. The control window should go blue both when a pregnancy test is positive as well as negative. If it doesn’t, it means the test has not worked.
use of monoclonal antibodies in research
Using monoclonal antibodies in research
Monoclonal antibodies can be used to locate specific molecules on a cell or in a tissue. First, monoclonal antibodies are made that will bind to the specific molecules you’re looking for. The antibodies are then bound to a fluorescent dye. If the molecules are present in the sample you’re analysing, the monoclonal antibodies will attach to them, and they can be detected using the dye.
