Chapter 4 Functional Anatomy Flashcards
Spiral Shapes
- Vibrio. Small bean shape.
eg. Vibrio cholerae, causes cholera. - Spirillum. Long and wiggly with antennas at one end.
- Spirochete. Very thin, long and wiggly.
eg. Treponema pallioum causes syphilis
Bacillus
Rod/staff shaped
- Single Bacillus
- Diplobacilli (2)
- Streptobacilli (chain)
Coccus
Orb-like
- Diplococci (2)
- Streptococci
eg. Streptococcus gyogenese. Causes strep throat. - Staphylococci
eg. Staphylococcus aureus causes skin infections, Toxic Shock Syndrome, food poisoning.
Coccobacillus
A mix between coccus and Bacillus.
Pleomorphic
Varies in shape and arrangements
Glycocalyx (Capsule)
Polysaccharides, Polysaccharides and polypeptides.
Why do they have capsules?
1. Increases virulence (capacity to cause disease)
eg. Streptococcus pneumoniae (pneumonia)
2. Increases the ability to attach to human/host cells
eg. Streptococcus mutans (dental caries)
3. Evade phagocytosis
Types of Flagella
- Monotrichous (1)
- Amphitrichous (2)
- Lophotrichous (many at one end)
- Peritrichous (coming from all corners)
Flagella Anatomy
- Filament (made of polypeptides and flagellin)
- Hook (protein in nature)
- Basal body
a. One set of rings (Gram Positive)
b. Two sets of rings (Gram Negative)
Flagellum Movement
Run-Tumble-Run
They tumble when they meet an object
Axial Filaments (endoflagella)
eg. syphilis
Has an outer sheath
Fimbrae
“Kiwi”
- Higher number of appendages compared to flagella
- The purpose is for attachment, not movement.
eg. Neiserrid gonorrhoeae (gonorrhea)
Pili/Pilus
It’s a link between two cells that facilitates DNA/genetic transfer from cell to cell.
eg. Escherichia coli
Cell Wall
Peptidoglycan 1. Glucose NAG: N- Acetyl Glucosamine NAM: N- Acetyl Muramic acid NAG - o - NAM - o - NAG 2. Proteins a) Polypeptide b) Tetrapeptide eg. NAM-oooo-NAM
Gram-Positive
- Several layers of peptidoglycan
- Teichoic Acid is present
a) Alcohol and phosphate.
i. Ribitol and PO4-
ii. Glycerol and PO4-
b) Wall teichoic Acids and lipoteichoic acid
c) Role of teichoic acid
i. Antigenic specificity
- markers for bacterial cells
ii. PO4- attracts cations (Ca2+, Fe+) into the cells
Gram-Negative
- Has 1 or 2 layers of peptidoglycan
- Has outer membrane
a. Phospholipid molecules/bilayer
b. Lipoproteins
c. Porin protein (channel to transport)
d. Lipopolysaccharide
i. recognition marker
ii. endotoxin is a poison released when you have an infection (causes fever, nausea, shock) - No teichoic acid
- Periplasmic space
Atypical Cell Walls
- Mycobacterium, M. tuberculosis, M. leprae (leprosy)
a. Mycotic acid (waxy, lipid) - Mycoplasms
a. lacks a cell wall, only has a plasma membrane (with steroids) - Archaea
a. No peptidoglycan.
Lysozyme Damage
Lysozyme: digest disaccharides in peptidoglycan (PG), found in mucus and saliva
Gram Pos
- has thick PG
- if the cell is damaged, it becomes protoplast: forms a wall-less gram and cell
- outer PG layer is broken
Gram Neg
- has a thin PG layer
- spheroplast: formed by the actin of lysozyme on a gram-negative cell
Both lead to cell death.
Penicillin Attacks
Penicillin inhibits peptide bridges in peptidoglycan (PG)
- Gram Pos is more affected (eg, strep throat)
- Gram Neg is less affected (except for newer penicillins)
Ribosomes
- Free floating in the cytoplasm
- Size is in Svensons
- Bacteria 70 S (50 + 30)
- Humans is 80
Antibiotics target the smaller size
Endospores
- PG
- DNA
- Ribosomes
- Di picolinic Acid - DPA attracts and binds to calcium, keeps the spores living
- lack of water and food.
Gram Pos - Bacillus anthracis (anthrax)
- Clostridium tetani (tetanus)
- Clostridium botulinum (botulism)
- C. perfringens (gangrene)
- C. difficile (colitis)
Gram Negative (only one) 1. Coxiella burnetti (causes Q-fever)
