Cytoskeleton Questions (9/10):
Centrioles are made of (9) microtubules
- Microtubules are what make up cilia and flagella; used for motility
o Cilia unique to protists & eukaryotes
o Flagella are whip-like appendages that are responsible for prokaryotic cell
motility
o Pili used to transfer DNA between bacteria during conjugation; no motile
function
- Microtubules form the spindle that separates homologous chromosomes
Intermediate filaments are structural proteins; provide resistance to mechanical stress and
compression forces
Microfilaments are used for movement and contain the actin filaments used in muscle
contraction
- Microfilaments are linked with cytokinesis
- Microfilaments are used for cell movement, such as with phagocytosis
- Microfilaments make up part of cell’s cytoskeleton
Exocytosis: releasing of substances, contained in vesicles, to the outside of the cell
Pinocytosis: refers to the ingestion of fluids (aka cell drinking)
Phagocytosis: engulfing movement to destroy a pathogen; microfilaments are responsible for
generating the momentum necessary for this process
Villi: macroscopic folding of tissue
Microvilli: folding of cell membrane that increase surface area of a cell
Epithelial tissue covers both internal and external surfaces of the body
Endothelial tissue covers only the internal surfaces of components of circulatory system
Gram + is purple and has a thick (peptidoglycan/lipoteichoic) wall
- Gram + will hold on to first stain, staining organism purple
- Gram + cell envelope thin
Gram – is pink and has a thin cell wall, but more layered cell envelope & additional
(lipopolysaccharide aka LPS) outer membrane
- Gram negative bacteria are considered to be more dangerous because it has additional
layer in cell envelope and LPS outer membrane that is an endotoxin & damages hosts
Transformation is when bacteria gets genetic information from the environment (Griffith
experiment with mice; R strain safe, S strain deadly)
- Also known as ‘competence’
Transduction is the transfer of genetic material using a bacteriophage
- Lytic phage = causes bacterial death
- Lysogenic phage = does not cause bacterial death
Conjugation is the transfer of genetic material via a conjugation bridge via a pilus/pili
Transposons are DNA sequences that can change their position within a genome; this
sometimes creates or reverses mutations