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 unprocessed 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
Rose Blackspot
Type - fungus
cause - Spores
Symptoms - black slash purple spots on upper surface of leaves
Cure - Burning infected areas in an enclosed chamber
Malaria
Type - protists
cause - mosquitoes are vectors for malaria
Symptoms - Recurrent fever, cough, muscle pains, headaches, sweats and chills
Cure - Vaccination, Mosquito Nets and repellent
read me
The Immune System is designed to protect us from viruses and bacteria but can also respond to Allergens such as pollen or dust.
The body usually identifies allergens as harmful as soon as they enter the sinuses. The immune system responds by producing antibodies to fight off the allergen. Although the immune system produces antibodies in relatively small quantities the first time it encounters an allergen, subsequent exposures result in a specific immune response.
With repeated exposure, the body produces large amounts of the antibody greater to that allergen and stimulates mast cells in the respiratory system to release histamine, a chemical responsible for traditional allergic symptoms such as a runny nose, coughing, itchy eyes, and sneezing. This same chemical is responsible for other allergic reactions in the skin that result in itches and some inflammation.
By releasing histamine and manufacturing allergic Symptoms the body has created a process to expel the allergen out of the body. Runny noses, coughing, and sneezing all help rid the body of the presumably harmful allergen.
Cancer
when abnormal cells divide in an uncontrolled way
Benign tumour
Stays and grows in one place
malignant tumour
grows into other tissues and metastasize
how cancer happens
How is malaria transmitted
lifecycle of mosquitos
methods of controlling mosquito (malaria’s vector) lifecycle
1) Draining stagnant pools of water - gives the raft of eggs / larva / pupa no stagnant water to live in so they die
2) Spraying pools of water with insecticides - It chemically kills the raft of eggs / larva / pupa
3) Spraying pools of water with oil - prevents pupa from breathing air & reduces O2 content of water so Larva & raft of eggs die
First line of defence against pathogens in humans
- mucus in mouth, nose, and trachea traps pathogens
- trachea and bronchus are lined with cilia, which “waft” mucus back up to the throat to be swallowed
- urine is antimicrobial and kills pathogens.
- scabs form a protective barrier to stop bacteria entering.
- tears are antimicrobial.
- hairs in nose to trap larger particles.
- skin is a tough barrier, with a dead outer layer of cells that microorganisms can’t penetrate, glands secrete antimicrobial oils.
- stomach is full of hydrochloric acid which kills microorganisms.
- Ear wax, eye lashes
Second line of defence against pathogens in humans
The second line of defence is also non-specific. It involves a type of white blood cell called phagocytes. They are attracted to any area of your body in which an infection is present. Then, they engulf the pathogen through phagocytosis.
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.
antigen
a specific shaped protein on the surface of each pathogen. They are specific to 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.
Memory Lymphocytes
After the infection and the pathogens have died, the memory lymphocytes and antibodies remain in the blood. What happens if you’ve got a secondary infection of the same, pathogen, your memory lymphocytes will very quickly produce correct antibodies which will bind to the pathogens, as no time needs to be wasted finding the correct lymphocyte.
Lymphocytes - antitoxins
Lymphocytes also make antitoxins which bind to any toxins the pathogen makes, neutralising it. Toxins are what make you feel sick.
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.
How does a vaccination work?
A vaccine is a small quantity of a dead or inactive pathogen. it still possesses the same antigens as a normal pathogen so that the body develops memory lymphocyte cells that’s recognise the active pathogen too.
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 one of monoclonal antibodies for so its present in the bloodstream.
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 from the mouse that produces the antibodies that you want to produce monoclonal antibodies for with a cancer cell aka 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 identical antibodies forming monoclonal antibodies, which are all specific to the same antigen.
3 uses of monoclonal antibodies
Diagnosis – eg pregnancy tests/ covid tests
Research - to locate or identify specific molecules in cells
Treatment – eg cancer treatment, binding to cells and carrying a radioactive or toxic substance
Which hormone is detected by pregnancy tests?
human chorionic gonadotropin
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 testing for disease
mAbs can be attached to fluorescent dyes that glow under UV light. They show where particular molecules are and detect specific cells.
phases of drug research
Preclinical - Tested on cells then on engineered mice. Does it work? how much? side effects?
Clinical - phase one - tested on a small no. of healthy male volunteers – safety?
Clinical - phase two - tested on a small number of patients - Does it work? how much?
Clinical - phase three - large scale trials - does it work for all? getting the dose right.
Clinical - phase four - distribution and scalability - despite drug being available it is still monitored and checked for long term effects
Single blind trial
patients don’t know who’s getting the placebo but doctors do.
double-blind trial
neither patients nor doctors know you who is getting the placebo and who isn’t. only drug company knows.
