Exam 1 Flashcards
Which stem cell is able to differentiate into all cell types of the body except for supporting cell types?
Pluripotent stem cells - found in early embroys
Describe plasticity
The ability to differentiate into many specialized cells
Name the 4 types of stem cells
Totipotent, pluripotent, multipotent, unipotent
Which stem cell can give rise to a small number of different cell types?
Multipotent cells
What are the main types of multipotent stem cells?
Skin, epithelial, neural, hematopoietic, mesenchymal
Where are mesenchymal stem cells located and what type of stem cell are they?
Located in: bone marrow, nervous system, adipose tissue, skin, muscle
Type of stem cell: Multipotent
What will lead to cancer after dysregulation?
Asymmetric cell division
How does asymmetric cell division differ from symmetric cell division?
Asymmetric results in 1 stem cell + 1 differentiated cell
Symmetric results in 2 stem cells or 2 differentiated cells
Stem cell division leads to what kind of cell?
Daughter cell
What is the microenvironment that controls stem cell renewal?
Stem cell niche
Stem cells directly contacting the ECM are preserved by what process?
Extrinsic Signaling
Stem cells outside of direct contact will differentiate by what process?
Extrinsic Signaling
What is the process called that reprograms adult cells into pluripotent stem cells via gene encoding?
Induced Pluripotent Stem Cells (iPS)
What substance joins actin bundles between cells?
Adherens
What are the 3 binding domains of laminin?
Cell, Collagen, Proteoglycans
Which type of junction prevents leakage between cells?
Tight juntions
What is a GAG and where are they found?
Repeating disaccharides of acidic sugar & amino sugar; highly negative
Found in the ground substance
Which type of protein can be described as ‘rubber-like’?
Elastin
What anchors filaments to the basement membrane (basal lamina)
hemidesmosomes
What anchors filaments between cells?
desmosomes
What leads to improper functioning of the immune system?
Too little cell adhesion
Too little cell adhesion means that
the immune system functions improperly
How can we describe a phospholipid head?
hydrophilic
How can we describe a transmembrane protein?
Amphipathic (hydrophilic out, hydrophobic in)
What do we call a molecule that contains both hydrophilic and hydrophobic parts?
Amphipathic (e.g. cholesterol)
What are cholesterol-rich microdomains that appear to be floating in fluid?
Lipid rafts
What are the functions of lipid rafts?
cholesterol transport, endocytosis, signal transduction
What are calveolae?
A type of lipid raft containing the protein calveolin
What is the composition of the fluid mosaic model?
Phospholipids & proteins
What type of motions can a phospholipid membrane make?
Lateral, rotation, flexion
What is highly concentrated in the myelin sheath of cells? This substance is also present in all animal cell plasma membranes.
Sphingomyelin
What is the composition of a phospholipid?
Fatty acids (hydrophilic) and a variable polar head group (hydrophobic)
What are the three phospholipids with nitrogen?
(Phosphatidyl)Choline, serine, ethanolamine
Which phospholipids lack nitrogen?
Glycerol, Inositol
Which protein doesn’t extend through the lipid bilayer?
Lipid-anchored proteins
What are the two types of cytosol of actin-binding proteins?
Gel- firm/more solid, longer F-actin
Sol - soluble/more liquid, depolymerized F-actin
What is a linear chain of heterodimers called?
Protofilaments (part of the structure of microtubules)
What contains a GTP cap?
Heterodimers
GTP cap = where new dimers are added
What is required for movement of chromosomes during division?
Microtubules
Microtubules are regulated by…?
centrosomes
The synthesis of ___ requires GTP
microtubules
Microtubules are required for what kind of transport?
Intercellular
What type of intermediate fiber is found in neurons?
Type IV
What intermediate filament structure does not require energy?
Tetramers
How many tetramers make up 1 intermediate filament?
8 tetramers
When G-actin monomers are added to the + end at the same rate as other G-actin is removed from the - end, that is called…
treadmilling
Treadmilling is the steady state of what type of microfilament synthesis?
F-actin
How many types of actin are found in non-muscle cells
2
What are the functions/nuclear functions of actin in non-muscle cells?
contraction & polymerization
nuclear: structure & gene transcription
What are the three roles of actin contraction in non-muscle cells?
cell movement
cell division
structural support
What prevents polymerization by binding G-actin monomers?
Profilin
What structure is the “Fed Ex” of the cell?
Golgi Complex
What is made in the golgi complex?
lysosomes
What are the three areas of the golgi complex?
Cis - faces RER, accepts protein
Medial - adds carbs, lipids, etc here
Trans - closest to plasma membrane, sorts/packages protein into vesicles
What part of the golgi complex sorts/packages protein into vesicles?
Trans
Within the lysosome, what is used to digest proteins, carbs, & lipids?
Acid Hydrolase
What is the difference between TEM/SEM magnification?
TEM = flat image, interior of cell SEM = 3D image, exterior of cell
True or False: Prokaryotes do not contain mitochondria.
True
True or False: Membrane-bound organelles are found in both Prokaryotes and Eukaryotes
False
What causes the death and breakdown of a host cell (lysis)?
Viral replication
Lysis can be broken down into 5 steps:
Attachment Entry Synthesis Assembly Release
When does a virus shed its capsid?
Once the virus is inside the host
What is a capsid?
Protein coat of a virus
Where are peptidoglyans located on bacteria?
The cell walls
What are the two types of peptidoglyans?
Gram (+) and Gram (-)
The thick, ‘purple’ cell walls on bacteria are…?
Gram (+)
The thin, ‘red’ cell walls on bacteria are…
Gram (-)
How is the viral envelope different from the capsid?
Viral envelope is acquired from the host cell during replication; the capsid is the protein coat of a virion
What is chemically modified during transport?
An active process called group translocation
What is acquired from the host cell during replication?
Viral envelope
What is the extracellular state of a virus called?
Virion
What is the function of the virion capsid?
Provides protection & means of attachment
In addition to a capsid, a virion can also have a…
phospholipid envelope which encloses the capsid/nucleocapsid
When is the intracellular state of a virus revealed?
Once the virus is inside of the host cell
Give two examples of where proteoglycans can be found
synovial fluid & mucous
When does microtubule disassembly occur?
When dimer addition slows & GTP cap is lost
What does the loss of the GTP cap prevent?
Prevents new dimers from binding (in microtubules); “banana peel effect”
What are the three steps of F-actin microfilament synthesis
Lag
Polymerization
Steady state —> treadmilling
