SB5a-f, SB5i Flashcards
What are the 3 factors that affect health?
Physical well being
1. Free from infections/injuries
2. Getting regular activity and good sleep
Social well-being
1. How well you interact with others
2. Having friends
3. How your surroundings affect you (e.g. if you are happy with your work/school etc.)
Mental well-being
1. How you feel about yourself
2. Having self-esteem
What are 3 communicable diseases?
- Flu
- HIV
- Gastroenteritis
What are 3 non-communicable diseases?
- Cystic fibrosis
- Sickle-cell anaemia
- Cancer
What is a communicable disease?
When a disease is contagious (can be passed from person to person/animal to animal).
What is a non-communicable disease?
When a disease isn’t contagious (cannot be passed from person to person/animal to animal).
Where do non-communicable diseases originate?
These diseases are usually inherited from parents. They originate from a mutation in genes or a lifestyle result.
What is the difference between correlation and causation?
Correlation: When one variable changes the other variable appears to change as well.
Causation: When one variable changes it causes the other variable to change as well.
What is malnutrition a result of?
Not having a balanced diet and not getting every nutrient needed.
What are 4 examples of deficiency diseases?
- Scurvy
- Kwashiorkor
- Anaemia
- Rickets
See SB5b table (booklet/book).
What can too much alcohol consumption cause?
Damage to the liver, causing cirrhosis of the liver.
What is the function of the liver and how does alcohol affect it?
Removing toxic substances from the blood that can cause harm to the body or blood. Too much exposure to ethanol (substance in alcohol) causes scar tissue on the liver (cirrhosis).
What are the long-term effects of alcohol?
- Cirrhosis of the liver
- Brain damage
- Blood clots in the brain
What are the short-term effects of alcohol?
- Blurred vision
- Loss of coordination
- Unconsciousness
- Vomiting
- Aggressiveness
- Memory loss
- Hangover
- Lowers negative feelings
What is the cost to society from the effects of alcohol?
- Accidents due to drunken drivers can cause injuries or death to themselves and others.
- Aggressive behaviour due to drinking could lead to damage of properties.
- Money and resources of hospitals are spent on treating drunk people and people with liver disease.
What is cardiovascular disease?
Cardiovascular disease (CVD) is a summary of many diseases that affect the heart and circulatory system (e.g. high blood pressure, heart attacks, strokes etc.)
Who have higher probabilities of suffering from CVD and why?
Overweight and obese people. This is because there are large amounts of subcutaneous fat under the skin and around vital organs such as the heart and kidneys.
What are 2 ways of determining someone is obese?
- BMI (Body Mass Index)
- Waist-to-hip ratio
How do we calculate BMI?
BMI (kg/m^2) = mass (kg) / Height^2 (m)
How do we calculate waist-to-hip ratio?
Waist-to-hip ratio = waist circumference / hip circumference
What are the factors and differences between BMI and waist-to-hip ratio?
BMI:
1. Does not distinguish between fat and muscle
2. Muscle weighs more than fat (this means athletes’ BMI could show they are obese but actually not due to having lots of muscle)
Waist-to-hip ratio:
1. Better way of determining obesity
2. Measures abdominal fat
The more the BMI and the waist-to-hip ratio, the higher the chance of someone suffering from CVD.
What are the effects and diseases caused by smoking?
- Increased risk of developing CVD
- Tobacco contains nicotine that vasoconstricts blood vessels, increasing risk of blood clots (could block artery in heart or brain causing heart attack or stroke)
- Increased blood pressure due to narrowing of blood vessels
- Tobacco contains carbon monoxide - a poisonous gas
- Carbon monoxide takes the place of oxygen in the blood, so blood carries less oxygen to the cells
Check picture SB5c (booklet/book).
Why do obese people get heart attacks?
- Artery wall gets damaged due to high blood pressure
- Lumen gets narrower because fat deposits into the wall of the artery
- This causes less blood flow to the heart muscle, less oxygen and glucose delivered to the heart muscle and less respiration causing cells to die
How do we treat CVD?
- Use bypass surgery so the blood can use another route to go to the heart muscle when a blood vessel is blocked at a certain point
- Use a stent (metal mesh tube) to keep the blood vessels wide
- Medication to decrease the formation of blood clots and preventing heart attacks/strokes
Check picture SB5c (booklet).
What is a pathogen?
Any microorganism that can cause a disease.
What are 4 types of pathogens?
- Viruses
- Bacteria
- Fungi
- Protists
Check SB5d table (booklet).
What are the characteristics of viruses?
- Not considered living organisms
- Do not have cellular structure (no cell membrane, no cytoplasm etc.)
- They multiply by inserting themselves into a host cell
- Insert their DNA into the DNA of the host and take over the cell’s DNA-copying processes
- Their DNA undergoes transcription and translation making proteins to make the new viruses
What are 6 ways pathogens can use in order to spread and how? Give examples.
- Water (cholera, typhoid, dysentery)
a. Drinking dirty/infected water
b. Washing with dirty/infected water - Air (flu, Chalara dieback, Tuberculosis, cold)
a. Sneezing and coughing sends droplets containing
pathogen
b. Certain pathogens can survive for long periods of
time and when they get mixed with dust, the dust
blows away and can infect others
c. Spread as tiny spores - Food (salmonella)
a. Enter the body through the mouth (oral route)
b. Touching infected food/not washing hands after
the toilet then touching your mouth
c. Pathogens on the feet of flies that come from
faeces and then sit on food - Vectors (malaria, dysentery)
a. Malaria protist is carried into the blood of
mosquitos that came from an infected person
b. Mosquito injects pathogen directly into the blood
of the other person - Body fluids (AIDS, Hepatitis)
a. Viruses enter the body of people through mouth,
nose, eyes, broken skin or through the exchange
of body fluids of the reproductive organs - Direct contact
a. Pathogens on surfaces get transferred on your
hands by touching them, which then get
transferred onto your face when touching it
What are 4 ways to stop spreading pathogens and how?
- Water
a. Keep water clean
b. Drink clean water - Air
a. Wear a mask
b. Use tissues when sneezing/coughing, throw them
away and wash your hands - Food
a. Cook food very well (e.g. meat)
b. Wash fruits and vegetables thoroughly
c. Store foods in the appropriate temperature - Vectors
a. Kill mosquitos (with special sprays)
b. Control spreading of disease by controlling
spreading of vector
What is the structure of viruses?
- Contain DNA/RNA
- May have outer lipid envelope
- Have protein coat/capsid made up of repeating capsomeres
- Some contain the enzyme reverse transcriptase
What is the process of the lytic cycle?
- Bacteriophage (type of virus) attaches on host cell
- Releases its DNA into the host cell
- Host’s DNA breaks down
- The virus uses all the processes in the cell to produce proteins lipids, carbohydrates, and DNA (all the parts needed to make a new virus)
- The new viruses are assembled and break the cell - destroying it - then leave to go infect other cells
Check SB5f diagram (booklet).
What is the process of the lysogenic cycle?
- Bacteriophage (type of virus) attaches on host cell
- Releases its DNA into the host cell
- The DNA gets incorporated into the DNA of the host cell
- The virus remains dormant
- As the cell multiplies to form new cells, the new cells also contain the DNA of the virus
- Once something triggers the virus, its DNA becomes active and enters the lytic cycle
Check SB5f diagram (booklet).
How do we make a bacteria lawn plate and test different chemicals, bacteria or viruses?
- Add the bacteria in the liquid gel
- Stir it, then put it in the petri dish to let it cool down
- Add the bacteria in the solid agar gel using an inoculating loop
4.
Check SB5f drawing (booklet).
How do we test which viruses attack bacteria?
- Take a petri dish and inoculate the nutrient agar with bacteria
- Create wells or use paper disks to add the viruses (can also use chemicals/antibiotics)
- Viruses will diffuse through the agar
- Incubate the petri dishes at 25°C for 3-7 days
- Check for a clear zone around the paper disks/well
- Clear zones show bacteria have died
- The bigger the clear zone, the more effective the virus is
- Calculate the area of the clear zone using πr^2
What aseptic techniques are used when performing experiments on bacteria?
- Sterilising inoculating loop with Bunsen burner flame
- Sterilising agar and equipment with an autoclave
- Keeping lids of petri dishes closed after bacterial growth
- Use of antiseptics to clean area of work
- Tape cross-wise the petri dish to avoid growth of anaerobic bacteria
Why are aseptic techniques used?
- Bunsen burner flame kills all microorganisms on the loop
- Loop is needed to be sterilised so that unwanted microorganisms are killed
- No competition of resources and space in the agar - only desired bacteria can grow
What are some controlled variables in experiments on bacteria?
- Concentration of antiseptic/antibiotic
- Volume of antiseptic/antibiotic
- Same type of agar
- Volume of bacteria
- Incubation temperature
- Growth period
What are the body’s 4 lines of defence?
- Physical barrier
- Chemical defence
- Macrophages
- Antibodies
What do physical and chemical barriers do and what are some examples of them?
Physical barrier: Stops pathogens from entering the body
1. Skin
2. Mucus
3. Cilia
4. Mucus membranes
5. Nasal hair
Chemical barrier: Kills the pathogens that enter the body
1. Sebum (oily substance in hair)
2. Hydrochloric acid (stomach)
3. Saliva - lysozymes
4. Tears - lysozymes
5. Mucus - lysozymes
6. Vaginal fluid - lysozymes
What are sexually transmitted infections (STIs) and how can they be spread?
Sexually transmitted infections (STIs) are certain pathogens transmitted through sexual intercourse.
They can be spread when sexual fluids come in contact and also be passed from the mother to fetus through the placenta. Many STIs do not develop any symptoms so people are not aware that they are infected.
How do we identify sexually transmitted infections (STIs)?
Screening is used to identify an infection by doing blood tests.
What are some examples of sexually transmitted infections (STIs)?
- HIV virus
- Chlamydia bacterium
What is a way to prevent spreading sexually transmitted infections (STIs)?
Use of artificial barriers (e.g. condoms) during sexual intercourse.
