Microbiology Bacterial Structures and Functions

Subclinical Infection

• A person can be infected but show no symptoms. This is known as a subclinical infection.

Bacterial Morphology

• Bacteria can be identified based on their morphology, color, and size.
• Cocci are round bacteria.
• Diplococci are pairs of cocci.
• Chains are a string of cocci.
• Bacillus anthracis forms chains but is not a cocci.

Bacterial Growth and Division

• Binary fission is the primary mode of bacterial reproduction.
• In gram-positive bacteria, the DNA attached to the septal mesosome divides in both directions, and the septum (cytoplasmic membrane) forms.
• In gram-negative bacteria, the entire bacterial cell constricts from the middle to form a septum.

Group Translocation

• This is an active transport process for sugars.
• A plasma membrane carrier protein becomes phosphorylated, binds to a sugar, and transports it across the membrane as a phosphorylated sugar.
• This process requires energy.
• The "Phosphotransferase System" is a name for this process..

LPS and Coagulation Pathway

• Lipopolysaccharide (LPS) can activate the coagulation pathway, leading to clotting.
• LPS induces platelet aggregation through alternate complement pathway activation.
• LPS activates coagulation reactions through Hageman factor (factor XII) activation.
• This leads to a series of factors converting to proteolytic enzymes until prothrombin changes into thrombin.
• Thrombin cleaves fibrinogen into fibrin, which forms clots.
• Fibrinogen has glycoprotein receptors on platelets which aids in aggregation.

Disseminated Intravascular Coagulation (DIC)

• Plasminogen is cleaved to plasmin, leading to fibrinolysis.
• This can result in disseminated intravascular coagulation (DIC).
• DIC causes thrombosis of capillaries (micro thrombi), leading to hypoperfusion, hypoxia, and hemorrhages (due to a lack of platelets).

This quiz covers key concepts in microbiology, focusing on bacterial morphology, growth, and transport mechanisms. It includes topics such as subclinical infections, types of bacteria, and processes like binary fission and group translocation. Test your knowledge on these essential topics.