Micro Organisms Flashcards
What do living things do
Reproduce
Grow
Excrete
Respirate
Nutrition
What do plants have
Chloroplasts for food
Mitochondria
And vacuoles
Prokaryotic
Don’t have a true nucleus, genetic materials are floating around
No nuclear membrane can
Eukaryotic
Have membrane bound organelles
Has nucleatic true membrane separating what’s inside from what’s outside
Pathogenic
Harmful and disease causing
Virus
Active and are difficult to cultivate
Virion
When dormant and not in contact with host cell
Characteristics of viruses
Microscopic
Not really living
Obligate intracellular parasites
Obligate intracellular parasites
Can only survive and produce inside cells of living organisms(hosts)
Replicate using host cell’s materials
Different shapes of Viruses
Polyhedral
Helical
Complex
Characteristics of Polyhedral Viruses
Cuboidal
Capsid has 20 triangular faces
Examples of Polyhedral viruses
Adenovirus
Coronavirus
Characteristics of Helical viruses
Spiral
Capsid resembles a coiled spring
Examples of Helical Viruses
Tobacco virus
Characteristics of complex viruses
Have a Head
Sheath
Tail
Examples of complex viruses
Bacteriophage
Structure of viruses
Acellular
Simple structure with a Core of DNA and RNA
Nucleic acid surrounded by capsid
What is Acellular
Is not a cell, has no nucleus, cytoplasm or organelles
What does a simple structure of DNA and RNA have
Hereditary material is not enclosed with a nuclear membrane
What is a Capsid
A protein coat
What is Symbiosis
Organisms live together and interact
Types of Symbiosis
Mutualism
Parasitism
Commensalism
Mutualism
Both symbiont and host benefit
Parasitism
Symbiont benefits to the detriment of host
Commensalism
Symbiont benefits with little effect on the host
What do Viruses infect
Animals, Plants and bacteria
Bacteriophage
Kill bacteria
What Kingdom does Bacteria belong to
Monera
Characteristics of Bacteria
Inhibits all environments
Extremophiles
Can be microscopic
Can be useful and can cause diseases
Types of Bacteria
Cocci
Bacilli
Spiralla
Vibrios
How are Cocci classified
Are spherical
How are bacilli classified
They are Rod-shaped
How are Spiralla classified
They are rod-shaped
How are vibrios classified
Are comma-shaped
What is Streptococcus
Exist singly
What is Staphylococcus
Exist in clumbs
What happens in favourable conditions
Bacteria reproduce rapidly by binary fission
What happens during Binary fission(mitosis)
A single cell divides into two with identical DNA
10- 15 mind
What happens in unfavourable conditions
Bacteria may survive by becoming dormant
How does Bacteria become dormant
They form spores with a thick protective coat around themselves
Structure of bacteria
Unicellular
Have protective rigid cell wall
Plasma membrane
Prokaryotic
Waxy layer
Produce by binary fission
Unicellular meaning
Simpler cell than those of other living organisms
What is the function of the plasma membrane
Serves as mitochondrion, endoplasmic reticulum & chloroplast
Controls entry & exit of materials
What does the Waxy capsule do
Serves as Bacteria’s outermost layer
What does a typical bacterium have
Flagellum
Cell wall
Cell membrane (inner wall)
Cytoplasm (inside)
Chromosome- plasmid
Waxy capsule (outer)
What are common characteristics of Protista
Eukaryotic
Life in moist environments cause no protection against drying out
Variable characteristics of Protista
Unicellular or multicellular
Microscopic or over 100m long
Heterographs or autotrophs
Another name for plant-like Protista
Phytoplankton
Another name for Animal like Protista
Zooplankton
Phytoplankton
Called algae
Aquatic eukaryotes
Contains chloroplasts
Base of aquatic food chain
Release oxygen through photosynthesis
Free floating
Autotrophic
What do algae do with chloroplasts
For asexual reproduction
Algae groups
Green algae
Red algae
Diatoms
Dinoflagellates
Green algae
Found in fresh water
Spirogyra and green seaweeds
Brown algae
Kelp
Can photosynthesise
Red algae
Found in deep water
Red sea weed
Diatoms
Microscopic
Unicellular
Cell walls contain silica
Dinoflagellate
Microscopic
Unicellular
Found in surface waters
Zooplankton
Called protozoans
Unicellular
Heterotrophic
Can’t make own food so ingest
Swim around actively
Protozoan groups
Amoeboids
Ciliates
Flagellates
Parasitic
Amoeboids
Ingest food by phagocytosis for intracellular digestion
Move by pseudopodia
What is pseudopodia
Temporary cytoplasmic projections
Ciliates
Use cilia to swim & capture food
E,g Paramecium
Flagellates
Use flagella for locomotion
E.g Giardia
Giardia
Causes diarrhoeal illness
Parasitic
Non-motile
E.g Plasmodium
Plasmodium
Causes malaria
Absorbs nutrients directly through the cell membrane
Autotrophs
Make their own food automatically
Heterotrophs
Eat other things (different food sources)
Suprotrophs
Decompose (break down things)
Live off dead things
Taxonomist
A person who classifies stiff according to their features
Fungi
Decompose organic matter
Share closer evolutionary relationship to animals than to plants as was originally thought
Characteristics of Fungi
Free-living
Usually invisible to naked eye
Are heterotrophs- no chlorophyll
Saprotronic
Some are parasitic
What does Fungi include
Yeasts, rusts, smuts, mildews, moulds, mushrooms and toadstools
What is free-living
Living in the soil
Air
Dead organic matter
Fungi that live in symbiotic relationships
Lichen
Fungi
What is Lichen
Association of fungi & algae
Fungi supplies algae with h2o & minerals while Fungi absorbs glucose made by algae
What is Mycorrhizae
Associates with the roots of many kinds of plants.
How is Fungi useful
Along with bacteria they’re primary decomposers of dead organic matter
How does Fungi reproduce asexually
By means of spores
How does Fungi reproduce sexually
When conditions are unfavourable, by resistant zygospores
How does Fungi reproduce budding
Binary fission e.g. the yeasts
Structure of Fungi
Mostly multicellular eukaryotes
Has Hyphae enclosed by rigid cell wall
Has spore producing bodies
Examples of unicellular species
Baker’s yeast
What is Hyphae
A mass of branched filaments
What is the cell wall that Hyphae is enclosed by made of
Chitin and glucan
What is a Hypha
A multi-branched tubular cell filled with cytoplasm
Can be aseptate or septate
What is HIV
Human Immunodeficiency Virus
What does HIV infect and how
CD4 cells, it deactivates them so the immune system isn’t alerted and it weakens
What are CD4 cells and what is their purpose
Helper T lymphocytes
Alert and alarm the rest of the immune system so it is ready to fight
Effects of HIV/ Aids in the body
Lack of energy
Rapid weight loss
Frequent fevers and swears
Fungal infections
How do we know that HIV has progressed to Aids
Blood tests show a CD4 count of less than 200 CD4 cells/ml blood
What is the normal CD4 count
600 to 1200
Other effects of HIV/ AIDS
Feelings of alienation due to stigma
- effects on economy
Destroys families
High financial costs
What to do when HIV negative
Take preventative measures
What to do when HIV positive
Learn to manage it and prevent transmission
Management of HIV/ AIDS
ARV treatment
Monitoring viral load
Treating opportunistic infections
Boosting immune system
Financial planning
Caring for mental & emotional health
ARV( anti-retroviral) treatment
Started when CD4 count is between 200 & 350
Doesn’t cure HIV
stops viral replication allowing immune system to recover
What is viral load
The amount of HIV is blood
What does an increased viral load show
That treatment isn’t working
How to Boost immune system to slow down effects of infection
Good diet, exercise, rest and no alcohol
Financial planning as part of HIV management
Must have access to media aid
How can pregnant women reduce risk of infecting babies
By taking ARVs during pregnancy and labour
What is drug resistance
The ability of disease-causing pathogens such as bacteria and viruses to continue multiplying despite the presence of drugs that usually kill them
Why are mutations very common
ARVs attack HIV at different stages of replication therefore it is allowed to replicate it does so at a rapid rate
How does HIV become resistant to the drugs
Mutations might block working of drugs making them less effective/ ineffective
How does drug resistance develop
Not taking drugs exactly as prescribed
Unsafe sed
Poor absorption of ARV drugs
Hoe does not taking drugs exactly as prescribed cause drug resistance
It lowers the blood levels of ARVs in the bloodstream allowing HIV to replicate freely
How does unsafe sex cause drug resistance
a drug-resistant HIV strain is transmitted from another person
How does poor absorption of ARV drugs cause drug resistance
Lowers blood levels thus increasing the chance of mutations
Tuberculosis
A chronic bacterial infection
Can affect all organs but is common on the lungs
Chronic
Long term
Pulmonary TB
A contagious disease primarily spread in the air in moisture droplets
What causes pulmonary TB
TB bacillus covered in a waxy coat allowing it to not be destroyed by immune system and remain alive for a long time
Super bug
Bacteria resistant to almost all known antibiotics
What happens to a strong immune system after infection
No symptoms
Infection contained by fibrous capsule and lies dormant for years
What happens to a person with a weak immune system after infection
Bacilli multiplies further and within 4 weeks person is ill of TB
What happens to a weak immune system after infection
Bacilli multiplies further & within 4 weeks person is ill of TB
Effects of TB
Weakness & tiredness
Cough sometimes blood
Weight loss
Lose earnings
Stigma
If untreated can affect 10- 15 annually
Killing people with HIV
Management of TB
BCG Vaccine
Screening
Treat infected patients immediately
DOTS
What is DOTS
Directly Observed Therapy, Short course
Six months regime
Monitored to take full course of antibiotics
Within days patient can’t infect others
Consequences of patients stopping medication once they feel a bit better
Prolonged illness
Patient becomes infectious again
TB bacillus develop resistance
What is MDR
Multi-drug-resistant TB
Expensive to treat
What is Malaria
Life threatening parasitic disease transmitted by mosquitoes (vector)
Effects of Malaria
Flu-like symptoms
Cerebral malaria
Premature babies
Death
Appear 10-14 days after bitten by infected mosquito
How can malaria cause death
Destruction of red blood cells
Clogging of capillaries that take blood to brain
Costs to government due to malaria
Loss of tourism income
Maintenance of health facilities
Public health interventions against malaria
Management of Malaria
DDT
Insecticide-treated nets
Treat illness
Treating Malaria
Expensive
Three day course using multi-drug treatment that includes artemisia which destroys drug resistant plasmids in the bloodstream
Candidiasis thrush
Caused by Candida albicans, a yeast or fungus
Effects of a Candida infection
Affect mucous membranes like mouth and vaginal
Makes one vulnerable to being infected by HIV
occur in intestines harmlessly
What can cause Candida overgrowth
Excessive taking of antibiotics
Suffering from immunodeficiency diseases
Stress, lack of sleep & poor diet
Warmth & moisture
How is Oral thrush treated
Anti fungal mouth wash
How are Vaginal yeast infections treated
Topical anti-fungal medication
Athlete’s foot
Caused by Tinea
Grows in damp places
Feeds on keratin ( protein in skin cells)
How can athlete’s foot be treated
Keeping affected parts dry
Applying anti-fungal powder
Infections
Cause by pathogenic viruses, bacteria, protozoans or Fungi
Immune response by plants
Infected cells are stimulated to
Produce salicylic acid
Activate resistance genes
Self-destruct and form an area of dead cells
Why do plants produce salicylic acid
Because it’s a plant hormone or signal
Why do plants activate resistance genes
To provide a strong & specific resistance to the particular pathogen
Why do plants self destruct and form an area of dead cells
To prevent infections from spreading
Immune response by animals
Skin
Primary response
Secondary response
Skin as an immune response by animals
Prevents entry of pathogens
What happens in the primary response by animals
Try to destroy pathogens & prevent them from spreading by inflammation or fever
What happens in the primary response by animals
Tries to destroy pathogens & prevent them from spreading by inflammation of fever
What happens in the secondary response by animals
Activate the immune system if pathogens do start spreading
What is immunity
The body’s active response to an infection involving lymphocytes & phagocytes
Types of Lymphocytes
B Lymphocytes
T Lymphocytes
B Lymphocytes
Pathogens have antigens on their surface, it tells the B lymphocytes that the pathogen is ‘non-human’ and is dangerous
After recognising its specific antigen it replicates producing clones
Then it produces antibodies
Which combine with antigens to destroy pathogens
Natural immunity
Occurs when a person has an attack of a disease so that antibodies are produced and give protection against a future attack
How do antibodies destroy pathogens
Cause bacterial cells to burst
Labels pathogens for phagocytes
Clumps pathogens together makeweak
Neutralize bacterial toxins
T lymphocytes
Matured in the thymus( gland in the chest) and then migrated to the lymph glands
Types of T lymphocytes
- CD4 cells
- killer T cells
- Suppressor cells
What do Killer T cells do
Destroy body cells infected by virus & some parasites
Insert perforin into target cell making it burst
What do suppressor cells do
Act as brakes stopping the immune response once an infection is over
What do CD4 cells do
Start immune response to infection
What are Phagocytes
Large Lymphocytes that can change shapes
Produces in the bone marrow
Can squeeze through gaps in capillary walls
How do Phagocytes destroy pathogens
Look for pathogens
Engulfs it
Takes it to cell forming phagosome
Hydrolytic enzymes in the vacuole digest & destroy pathogen
Antibiotics
Fight infections caused by bacteria
Don’t work for viral infections lol
How antibiotics work
Antibiotics help the immune system by destroying the bacteria directly
How do antibiotics destroy bacteria directly
Prevent proper formation of the cell wall
Damage cell membrane
Affect RNA and prevent protein synthesis
How do Antibiotics prevent the proper formation of the cell wall
Causes bacteria yo become unstable and burst
E.g Penicillin
How do Antibiotics damage the cell membrane
By changing its permeability causing the cell to leak its content & die
How do Antibiotics affect RNA and prevent protein synthesis
By preventing the bacteria from forming cell proteins and enzymes so it dies
Side effects of Antibiotics
Nausea, diarrhoea, stomach cramps and vaginal yeast infections
Allergies from penicillin
Itching and shortness of breath
Why do resistant populations develop
Repeated & incorrect use of antibiotics
Wrong diagnosis
Unnecessary prescription
Iks
Indigenous knowledge systems
Anaerobic respiration
Respiration without oxygen
In the presence of sugar, bacteria & fungi produce
Traditional technology in food production
Sorghum beer
Maas
Mahewu
Bacteria in food industry
Yoghurt
Cheese
Fermented foods
Vinegar
Fungi in food industry
Bread
Alcohol
Medical biotechnology
Vaccines
What is a vaccine
A suspension of dead, weakened or fragmented micro-organisms or their toxins that will stimulate the production of antibodies which will produce blood immunity
Prevent diseases
Function of Cellulose-degrading fungi or Bacteria
They clean up dead plants in the environment
What is the function of saprotropic bacteria and fungi
Breakdown the remaining organic matter into carbon dioxide and nutrients
Functions of blue-green algae and phytoplankton
The replace and generate 50% of all oxygen used
