Chapter 3 Flashcards
What are the four major processes of life?
Growth - increase in size
Reproduction - Asexsual or sexsual
Responsiveness - change internal or external in reaction to stimulus
Metabolism - take in nutrients and use them to provide energy, growth, reproduce, and be responsive.
Give an overview of Eukaryotes cells.
Have nucleus
Internal membrane bound organelles
Larger (10–100 µm diameter)
More complex structure
Include algae protozoa, fungi, animals and plants
Give an overview of Prokaryotes cells.
Lack nucleus
Lack membrane bound organelles
Are small (1.0 µm)
Simple structure
Include bacterai and archaea
What is the function and composition of gycocalyes?
Outermost layer
Made of polysaccharides, polypeptides or both
Gelatinous, sticky
Made within and extruded to the outside.
What are benefits for human health with gycocalyes?
NOTES: Do not understand the difference between slime layers and capsules
Protect from desiccation
Often indicator of pathogenicity (virulance factor)
Viscous (sticky), S. mutans
Avoid detection by host S. pneumoniae
Describe the function and structure of bacterial flagella.
Made of flagellin protein
Basal body, hook, filament
The basal body anchors the filament and hook to the cell wall by a rod and a series of either two or four rings of integral proteins.
360 rotation motion, not wavelike. Ethier direction
Counterclockwise = runs
Clockwise = tumbles
What are the flagellar arrangements?
Monotrichous (single polar)
Lophotrichous (tuft of polar)
Amphitrichous (both ends)
Peritrichous (entire surface)
Axial filament
Give an overview of fiimbriae
Sticky, bristle like projections
Used for adhesion to one another, to hosts, and to surfaces
Shorter than flagella
Serve an important function in biofilms
Give an overview of pili
- Special type of fimbriae
- AKA conjugation pili
- Longer than fimbriae but shorter than flagella
- Only one or two per cell
- Mediate transfer of DNA from one cell to another
Define the term capsule.
Organized repeating units of organic chemicals firmly attached to the cell surface that form the glycocalyx.
Define the term slime layer.
A loose, water-soluble glycocalyx
What is facilitated diffusion?
Movement of substances
across a cell membrane via protein channels.
What is diffusion?
Diffusion is the net movement of a chemical down
its concentration gradient—that is, from an area of higher concentration to an area of lower concentration.
What is osmosis?
The diffusion of water across a selectively permeable membrane
What is an isotonic state?
When solutions on either side of a selectively permeable membrane have the same concentration of solutes
What are some characteristics of Fimbriae?
- Sticky, bristle like projections
- Used for adhesion to one another, to hosts, and to surfaces
- Shorter than flagella
- Serve an important function in biofilms
What are biofilms?
Organized, layered systems of bacteria and other microbes attached to a surface.
What is the function of the basal body?
Functions to attach the flagellum to the cytoplasmic
membrane
What are the characteristics of Peritrichous bacterial flagella?
They cover the cell
What is the Periplasmic space?
The space between the cytoplasmic membrane and the cell wall.
What are some characteristics of bacterial cell walls?
- Give bacterial cells characteristic shapes
- Protect cell from osmotic forces
- Can be a target of antibiotics, or aid in resisting antimicrobial drugs. (penicillin)
- Are composed of peptidoglycan
- Are described as two basic types, Gram-positive and Gram-negative
What are positive taxis and negative taxos?
Movement toward a favorable stimulus is positive, movement away from a favorable stimulus is negative
What is meant by gram positive?
Gram-positiveis a term used to describe bacterial cell walls that have a relatively thick layer of peptidoglycan that also contain unique chemicals called teichoic acids.
What is meant by gram negative?
Gram-negative is a term used to describe bacterial cell walls that have only a thin layer of peptidoglycan, but outside this layer is an asymmetric bilayer
membrane.
