6 Disease Flashcards
what does TB stand for?
mycobacterium tuberculosis
what are the 10 components of bacteria:
1-flagellum
2-lipid granule
3-ribosome
4-pili
5-genetic material
6-slime capsule
7-cell wall
8-plasma membrane
9-cytoplasm
10-plasmid
what are the 4 main components of viruses? (gerc)
Genetic material + packaged Enzyme
lipid Envelope
Receptor proteins
Capsid
what type of genetic material can viruses have?
DNA or RNA
what type of genetic material does bacteria have?
DNA ONLY
what does bactericidal antibiotic mean?
the antibiotic will DESTROY bacteria
what does bacteriostatic antibiotic mean?
inactivates bacteria by preventing reproduction
how do bactericidal antibiotics work?
- inhibit cell wall synthesis → leads to lysis
- disrupt cell membrane so change in permeability = no bonds in cell wall = no growth
how do bacteriostatic antibiotics work?
-inhibit nucleic acid synthesis- prevents cell division and the production of proteins
how can bacteria spread resistance?
using tubes or pili it can directly share a copy of its DNA plasmid
what do antibiotics treat?
bacterial and some fungal infections
what is one way codes of practice have evolved?
- doctors less willingly hand out antibiotics to lessen the chances of resistant bacteria developing
- emphasising the importance of carrying out the full dose, the remaining 1% not killed could mutate and gain resistance
what’s some improved hospital practice?
- constant washing of hands
- hand sanitiser
- masks
what makes agar jelly a good culture medium?
contains food carbs/proteins
is TB contagious?
YES
how is TB easily spread?
droplets or airborne pathogens
Why is it advantageous to TB bacteria to infect the upper part of the lung?
- TB is an aerobic bacterium which needs oxygen
- upper part has highest conc. of oxygen
what is meant by granuloma?
a growth of tissue produced around an area of infection
what are granulomas like in TB?
anaerobic and contain dead bacteria and macrophages
name the process by which macrophages ingest bacteria.
phagocytosis
what 3 conditions can weaken the immune system making you more susceptible to TB?
- HIV
- chemotherapy
- recent organ transplant
explain how TB can evade the immune response.
- infect macrophages, other WBCs cannot detect them, antigens remain hidden
- cannot be broken down due to tough waxy cell wall
- lies dormant for many years
state some symptoms of TB
- coughing blood
- short breath
- fever
- unexplained weight and appetite loss
how can TB lead to secondary infections? death?
- macrophages are unavailable to destroy other pathogens
- slower response
- once in blood it can travel to other vital organs and spread
why are some countries more prone to TB? 5 points
- poor sanitation
- overcrowding
- lack of vaccines
- cost of antibiotic for the whole 6 months
- larger HIV population → more TB
why would a HIV infection increase risk of TB?
attacks immune system and T helper cells
what organ is most commonly infected with TB?
Lungs
outline the treatment for TB
- at least 3 diff antibiotics over 3-9 months
- rest and healthy diet
what does HIV stand for?
human immunodeficiency virus
what does AIDS stand for?
acquired immune deficiency syndrome (final stage of HIV)
what are the 6 components of HIV?
- gp 120 molecule (glycoprotein)
- lipid bilayer
- layer of viral proteins
- capsid
- 3 viral proteins
- 2 RNA strand
what are the 3 viral proteins of HIV? (rip)
- reverse transcriptase
- Integrase
- protease
how does HIV replicate?
- HIV gp120 binds to CD4 receptor
- viral RNA and proteins are down into cell
- RNA reverse transcribed into DNA
- Integrase inserts viral DNA into hosts DNA
(latency period)
- once translated and transcribed, protease modifies the proteins
- viral genetic material and protein packaged in capsid
- capsid exits to infect another cell
explain the meaning of latency in replication of HIV.
Dna inserted into host cells chromosomes
what does reverse transcriptase do?
produce DNA from viral RNA
what does integrate do?
inserts viral DNA into host cell DNA
what does protease do?
modifies proteins after transcription and translation
how is HIV transmitted from person to person?
-semen, blood vaginal fluid via unprotected sex or sharing needles, breastfeeding
what type of cells dies HIV infect?
T helper cells - with CD4 receptor
what symptoms come from HIV?
flu like eg sweating, vomit, fever, sometimes none
how can HIV lead to death?
- high HIV count but Loe T helper (bad as this is important in triggering an immune response)
- susceptible to secondary disease eg cancer, TB
