Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
What are the "big three" pathogens that are responsible for the most prevalent infectious diseases worldwide? What types of organisms are they?
|
HIV (virus), tuberculosis (bacteria), and malaria (eukaryote)
|
|
|
What are specific challenges faced by extracellular pathogens, and by intracellular pathogens?
|
Extracellular: must avoid extracellular immune attack from phagocytes (neutrophils), antibody, serum component (APOL1), trypanosome brucei
Intracellular: must manipulate host cell biology, invade, replicate, escape + spread |
|
|
How does Trypanosoma brucei evade antibody-mediated immunity?
|
They change surface proteins, so that the antibodies cannot consistantly recognize them. VSG = variable surface glycoprotein.
|
|
|
What is APOL1?
|
a serum component that is partially protective against trypanosome infection. uses innate immune response of host to lyse membrane
|
|
|
How are apolipoproteins in HDL and LDL internalized by cells? What are the stages of this process?
|
a
|
|
|
How does APOL1 kill trypanosomes, and how do some trypanosome species avoid killing?
|
a
|
|
|
How does HIV bind to cells?
|
a
|
|
|
How is HIV internalized?
|
a
|
|
|
How does Listeria monocytogenes solve the problems of internalization, intracellular growth, an cellular exit/spread?
|
a
|
|
|
Think of an example of how cell biology has contributed to our understanding of infection. Think of another example of how studying an infectious agent has contributed to our understanding of cell biology.
|
a
|
|
|
What features distinguish the 3 domains of life, and how were eurkaryotic cells thought to originate?
|
bacteria - single celled prokaryotes
archea - same eukaryotes - single or multi celled, thought to be a combo of bacteria (mitochondrion) and archea? |
|
|
What are typical sizes and volumes for different types of cells?
|
bacteria - .5 to 1 um diameter, v 1 fl
archea - 2.5 um diameter, v 60 fl eukaryotes - 25 um diamtere, v 5000 fl |
|
|
What are the key microscopy concepts that are relevant for visualizing cells and intracellular structures?
|
magnification, resolution, contrast
|
|
|
What are the key types of molecules relevant to cell biology, and how common is it that they interact with each other?
|
nucleic acids, proteins, and lipids interact with each other often
|
|
|
How many of each type of molecule are present in a simple cell, and how crowded with molecules is the cell interior?
|
water > inorganic ion > lipid > dna > protein > membrane protein > ribosome > mrna
|
|
|
What techniques do cell biologists use to localize specific molecules in cells?
|
fluoresence microscopy
|
|
|
What are the three major types of lipids that make up cell membranes, and how are they spatially organized in cells?
|
phosphoglycerides, sphyngolipids, and cholesterol
|
|
|
Why do cellular lipids spontaneously form bilayers?
|
Shape and amphipathic nature
|
|
|
How to lipids behave in cellular membranes - are they generally ordered or disordered, are they fluid?
|
fluid yes, and ordered
|
|
|
What is FRAP, and how can FRAP be used to observe the fluid movement of membrane proteins in membranes?
|
fluoresence recovery after photobleaching, 1) express fluorescent membrane protein ex. gfp, 2) use laser to bleach small area and lose fluoresence 3) wait and watch if still fluorescent proteins move into that spot in membrane. PROVES fluidity
|
|
|
How do membrane proteins provide functionality to membranes?
|
1) movement of molecules across membrane (ions)
2) signaling |
|
|
What are three types of integral membrane proteins? Four types of peripheral membrane proteins?
|
Integral: pump, carrier, channel
Peripheral: |
|
|
What is a hydropathy plot, and how can this be used to predict alpha-helical transmembrane domains?
|
plotting of which amino acids are hydrophobic vs hydrophilic
|
|
|
What kinds of molecules do cells sense and respond to?
|
nutrients, toxins, (environment) pheromones, (other beings) signaling molecules (other cells)
|
|
|
What are the common cellular locations of receptors? Where are signaling cells located with respect to receiving cells?
|
cell surface, nuclear membrane?
endocrine, paracrine, autocrine, contact dependent |
|
|
What is the definition of signal transduction?
|
conversion of one type of signal to another type of signal
|
|
|
What are four basic functions of intracellular signal transduction pathways?
|
relay, amplify, integrate, ditribute
|
|
|
What is a basic difference between different signal transduction pathways that can influence the timing of the response (faster versus slower)?
|
fast: alter function of existing proteins (phosphorylation)
slow: alter gene expression (translation/transcription) |
|
|
Define the Kd for the receptor-signal interaction. Why might a signaling pathway be designed to elicit a response when only a small proportion of receptors are bound to signaling molecules?
|
Kd = concentration of solvent at which 50% of receptors are bound to ligand, and I DONT KNOW
|
|
|
How are RTKs activated? What are the first steps in the pathway?
|
bind ligand, intracellular domain is activated to phosphorylate tyrosines
|
