2 - Human Diseases Flashcards
(7 cards)
Cholera Transmission and Symptoms
Transmitted by ingestion of water or food that is contaminated with faecal material containing the pathogen
Symptoms:
Diarrhoea
Dehydration
Cholera Cause
Spec ( Cholera bacteria secrete toxins which increase the secretion of chloride ions into the lumen of the intestine.
This affects the water potential gradient across the intestinal epithelium and results in severe diarrhoea.)
Cholera bacteria open the chloride ion channels by releasing toxins
Chloride ions from epithelial cells enter lumen of small intestine
Lowers water potential of lumen, so water moves through osmosis into the lumen from surrounding cells
Loss of water through faeces
Cholera Treatment
Oral Rehydration Therapy
Just drinking water is ineffective because intestine is not absorbing water and ions are not being replaced
Rehydration solution must contain:
Water
Sodium
Glucose
Potassium
Other electrolytes (ions)
HIV Structure
Core:
-Genetic material
-Reverse transcriptase
Capsid:
-Outer protein coat
Viral Envelope:
-Extra outer layer made from host cells membrane
-consists of lipid bilayer made from cell membrane of host helper T cell
Protein attachments:
-Attaches to receptors on host helper T cells
Replication of HIV
Attachment proteins on the HIV attach to receptors on a helper T cell
HIV releases its RNA into the helper T cell
Reverse transcriptase converts this RNA into DNA
DNA polymerase used to make this double-stranded viral DNA
Integrase enables viral DNA to be integrated into a host cell DNA
viral DNA used to make new HIV copies
Made at (host cells) ribosomes
Lipid envelope acquired from plasma membrane of
infected cell
Fully assembled HIV particles leave the cell in order to infect other cells
Retrovirus
RNA used to synthesise DNA
Enzymes in HIV
Reverse Transcriptase
-Converts viral RNA into viral DNA
Integrase
-integrates the viral DNA into the host’s DNA
Protease
-Produces viral proteins
