Infection and response

Pathogen

Micro-organism (virus, bacteria, fungi, protist) that causes disease

how can spread of infectous diseases be reduced

viruses…. and how they spread and multiply

are not cells and living organismsand require a host to replicate. They can spread through direct contact, airborne transmission, or contaminated surfaces.

bacteria

single-celled microorganisms that releases toxins which can be pathogenic or beneficial.

antibiotic

A medecine that kills bacteria

Who dicovered antibiotic and how

Alexandra Fleming, when he noticed penicillin created a ring free bacteria

Antibiotics work by

Inhibits DNA and protein synthesis

Painkiller

Substance that reduces symptoms of an illness

immune

Being resistant to a disease

pathogens can be spread by...

Direct contact, water, air droplets

Spread of disease can be reduced by...

Simple hygiene measures, vaccination, destroying vectors

E. Coli:

Bacteria- diarrhoea, vomiting, stomach pain

Measels (Rubeola):

Virus- fever, red eyes, red spots

chicken pox:

Virus- raised red spots, fever

athlete's foot:

Fungus- red, itchy skin between toes, skin peeling off

Gonnorea:

Bacteria-green yellow discharge, pain when urinating

Why cant antibiotics be used to cure viral diseases

Viruses are surrounded by protein coating; doesnt have cell walls that can be attacked by antibiotics like bacteria

Difference between painkillers and antibiotics

Painkillers soothe the patient while antibiotics treat the infection (by inhibiting microbes)

Rose black spots (plants)

Caused by Fungus- turns leaves yellow - spread by water or wind- treat by fungicide

Tobacco Mosaic Virus (plants)

Caused by virus- discoloration on the leaves- spread by workers clothes- cannot treat

Aphids (plants)

Caused by insects- wilting of the leaves- spread by aphids breeding- treat by ladybirds

Nitrate deficiency (plants)

Caused by lack of nitrate- stunted growth- impacts are less amino acid(less growth)- treat by fertiliser

Magnesium deficiency (plants)

Caused by lack of magnesium- yellow leaves- less chlorophyll (less growth) treated by fertilisers

Non- specific deficiency: nose

Hair and nose traps pathogens

Non- specific deficiency: eyes

Anti-microbal tears

Non- specific deficiency: trachea

Secrete mucus which traps pathogen=> cilia moves mucus

Non- specific deficiency: stomach

Contains hydrochloric acid which kills microbes

Non- specific deficiency: platelets

Clots blood

Non- specific deficiency: skin

Physical barrier

specific deficiency: different pathogens

Can be identified by a protein in their surface called antigens (each pathogen has a unique antigen)

Specific deficiency: different lymphocytes (White blood cells)

Can be identified by a protein in their surface called antibodys (each pathogen has a unique antibody)

Immune response order

1) a pathogen enters the body

2)lymphocytes produces antibodies (complementary to the antigen)

3)antibodies bind to the antigen

4)antibodies neutralise/destroy the pathogens

5)the same pathogen re enters the body

6)antibodies are produced rapidly due to reinfection

7)the pathogen is destroyed before it causes harm leaving the memory cell

Phagocytosis

Engulf and destroy white blood cells

Role of vaccines

Injects dead or inactive cells to the body

-to simulate white blood cells

-for then it to produce antibody specific to pathogen

Calculating bacteria division

(Bacteria divides by mitosis, makes genetically identical copies of itself, e coli divides every 20 minutes) e.g: E. coli after 3 hours: 60 x 3= 180 180/20= 9 2(bcs doubles) 2^9 x 1(bcs started with 1) =512