EXAM 1 Chapter 11, Protozoan Groups Flashcards
Protozoan groups belong to the kingdom _____ and the phylum _____
Kingdom Protista
Phyla Protozoa
Phyla Protozoa characteristics..
- most unicellular
- organelles
- free-living, mutualists, or parasites (don’t live in a colony, live by themselves, or some live with others, and others feed off them
- aquatic to terrestrial
- asexual or sexual reproduction
Their locomotion involves
cilia and flagella
Cilia are
short, many in number
flagella are
single or small numbers, longer
cilia move by…
performing power stroke and then a recovery stroke
flagella…
are undulates, they move back and forth to move forward
but some also pull organisms like propeller
…..covered in cilia
trachea, bronchi, bronchioles of respiratory system
Primary ciliary dyskinesia (PCD)
- rare genetic lung disorder
- also known as Immotile Cilia Syndrome
- symptom - chronic respiratory tract infections
Cystic Fibrosis (CF)
mucus collects in airway and cannot move mucus and gets clogged
- genetic disorder, affected lungs most critically, also pancreas, liver, intestine
- characterized by thick, viscous secretions in the bronchi which cannot be transported by cilia to the pharynx
- bacteria thrive in the altered mucus, which collects in small airways of lungs
- leads to formation of bacterial microenvironments known as biofilms that are difficult for immune cells and antibiotics to penetrate
- most people with CF dont live past 30
Chronic obstructive pulmonary disease (COPD)
its because of scarring of tissue in lungs, not because of cilia
two main categories of COPD are
emphysema and chronic bronchitis
emphysema
walls of alveoli are damaged (gas exchange is reduced)
chronic bronchitis
- lining of airways constantly irritated and inflamed
- causes lining to thicken (excess mucus) meaning reduced diameter of tubes in respiratory system, which means its hard to breathe
main cause of chronic bronchitis
smoking
cilia and flagella have…
the same internal structure
the structure includes
- 9 peripheral doublets with 2 central singlets (all MICROTUBULES)
- doublets are linked by nexin
- dynein arms between each doublet
- dynein arms have ATPase (generation of ATP)
- doublets linked to singlets via radial spokes
the dynein arms
- are club like structures
- inner and outer dynein
- splits ATP and uses the energy
- doublets almost climb up using dynein arms
- grabs/binds to doublets in front of it, reach up, grab and pull and this causes bending/swaying motion of cilia
the doublets..
climb up/slide past each other’s back using the dynein arms
the sliding action..
translated to bending via nexin and radial spokes
nexin…
-causes it to bend, essential
- it connects one doublets to the others
- if nexin is broken, would elongate but not bend
another type of locomotion used by some is..
pseudopodia (false feet)
two types of pseudopods are
- lobopodia (blunt extension)
- axopodia (thin extension)
in an amoeba (lobopodia), there is a
endoplasm (fluid)
ectoplasm (gel, appears transparent
Actin filaments are..
bound in the ectoplasm, unbound in the endoplasm
When an amoeba wants to move…
- the endoplasm with action filaments is bound to regulatory proteins (so that they don’t bind to each other and become gel-like and not fluid)
- then the lipids in the membrane frees actin from regulatory protein
- Actin assembles and cross link (forms ectoplasm tube through which endoplasm flows
- Ca2+ triggers actin severing proteins and initiates interaction w/ myosin (contracts rear of organism, like squeezing tube of toothpaste from the back
- disassembled actin units bind w/ reg. protein and are recycled
Myosin is
-another movement molecules (similar to dynein arms)
- when it contracts causes back of organism to contract to help movement
endoplasm….
ectoplasm…
endo = actin monomers bound to regulatory proteins
ecto = actin filaments cross linked by actin binding proteins (ecto all around)
membrane in front
bulges due to Brownian motion (random movement of molecules due to kinetic energy in the form of heat)
after membrane bulges..
actin monomers lose regulatory protein due to lipids in membrane, polymerize (form actin filaments) and get added to front sections of ectoplasm via actin binding proteins
While the ectoplasm is getting assembled in front, in the rear of amoeba,
actin filaments in ectoplasm get disassembled and interact with myosin, contract and pull rear of membrane inward pushing endoplasm forward, Ca2+ ions initiate contraction
This whole process continues with…
more ectoplasm disassembly in the rear which then gets recycled and moved forward as endoplasm
2nd type of pseudopod is
axopodia (thin extensions supported by microtubules)
- there is still ecto and endo, but supported but long rods of microtubules
- can capture and eat things with these
- can extent and contract arms (deconstruct and grow)