cell bio quizlet

• Cytoskeleton


  -Complex network of filaments in the cytoplasm and the nucleus.

  -Pretty dynamic/not static
• Cytoskeleton functions


  1. strength

  2. Cell movement

  3. Cell division (microtubules)

  4. Orientation of organelles- physically associated with the microtubules

  5. movement of vesicles, proteins, etc
• 3 major constituents of the cytoskeleton

  1. microtubules

  2. microfilaments

  3. Intermediate filaments
• Microfilaments


  -Smallest of the 3 constituents of the cytoskeleton

  -Actin filaments, f-actin (filamental actin)

  -Found in the cortex of cells 7-9nm

  -Formed a double helix

  -Made of monomeric units (types of actin)

  -Polarized

  -Tracks for myosin

  -don't stretch much
• Microtubules


  -largest tubular constituent of cytoskeleton

  -involved in cell division-major target of certain therapeutic drugs

  -polarized

  -decent strength

  -molecular motors

  -usually made of 13 profilaments

  -alpha tubulin/beta tubulin building blocks which are dimers
• how many protofilaments in a singlet is the norm for microtubules?

  13
• alpha tubulin


  GTP is non exchangeable for this building block of microtubules
• beta tubulin


  GTP is exchangeable for this building block of microtubules
• GTP cap


  for the positive end, these stabilize the microtubule
• microtubule experiment


  addressed the question: are microtubules used as guides for organelles or vesicles?

  -Showed low cAMP concentrations associated with aggregated melanosomes

  -showed High cAMP associated with dispersed

  -Add microtubules inhibitors and decrease cAMP, nothing happens.

  -microtubules are critical to this process.
• MAPs

  "microtubule associated proteins"

  -very diverse and functionally important

  -Experiment (11/22) in which migment granules use microtubules [figure 18-29a & b ]
• Intermediate filaments


  -"rope"

  -Example: keratin filaments (associated with desomosomes)

  -unpolarized

  -cell and tissue integrity

  -won't snap, so not usually very dynamic

  -5 groups
• 5 groups of intermediate filaments

  1. lamins

  2. acidic keratins

  3. basic keratins

  4. Desmin, GFAP, vimentin

  5. Neurofilaments (NFL, NFM, and NFH)

  see table 18-1
• lamins


  -Lamin A.B.C. nucleus

  -phosphorylation of lamin B triggers mitosis
• epidermolysis bullosa simplex


  -sloughing off of skin and shearing skin when touched.

  - rare genetic disease from defective intermediate filaments

  -Dr. Eisenberg created treatment
• Dr. Eisenberg


  -Australian general practicioner who created drug ortec since his son had Epidermolysis bullosa simplex

  -found he could create substitute skin cells from infant foreskins and delivers them to the collagen matrix.
• ortex/OrCel


  -Commercialized treatment for Dr. Eisenbergs method of treating epidermolysis bullosa simplex
• Actin


  -makes up 10% of muscle cells

  -all other cells makes up 1-5%

  -is a major protein

  -filaments required for phagocytosis
• g-actin


  -Globular protein.

  -are the monomeric units that make up microfilaments

  relies on ATP
• f-actin

  -filamentous protein
• How many actin genes do humans have?

  6, they are ancestral genes too
• Polarity and Actin

  -minus (1) end and plus (+) end

  -there's actually no difference in charge

  -decorating f-actin with the myosin S1 head unit
• Cytoskeleton


  -Complex network of filaments in the cytoplasm and the nucleus.

  -Pretty dynamic/not static
• Cytoskeleton functions


  1. strength

  2. Cell movement

  3. Cell division (microtubules)

  4. Orientation of organelles- physically associated with the microtubules

  5. movement of vesicles, proteins, etc
• 3 major constituents of the cytoskeleton

  1. microtubules

  2. microfilaments

  3. Intermediate filaments
• Microfilaments


  -Smallest of the 3 constituents of the cytoskeleton

  -Actin filaments, f-actin (filamental actin)

  -Found in the cortex of cells 7-9nm

  -Formed a double helix

  -Made of monomeric units (types of actin)

  -Polarized

  -Tracks for myosin

  -don't stretch much
• Microtubules


  -largest tubular constituent of cytoskeleton

  -involved in cell division-major target of certain therapeutic drugs

  -polarized

  -decent strength

  -molecular motors

  -usually made of 13 profilaments

  -alpha tubulin/beta tubulin building blocks which are dimers
• how many protofilaments in a singlet is the norm for microtubules?

  13
• alpha tubulin


  GTP is non exchangeable for this building block of microtubules
• beta tubulin


  GTP is exchangeable for this building block of microtubules
• GTP cap


  for the positive end, these stabilize the microtubule
• microtubule experiment


  addressed the question: are microtubules used as guides for organelles or vesicles?

  -Showed low cAMP concentrations associated with aggregated melanosomes

  -showed High cAMP associated with dispersed

  -Add microtubules inhibitors and decrease cAMP, nothing happens.

  -microtubules are critical to this process.
• MAPs


  "microtubule associated proteins"

  -very diverse and functionally important

  -Experiment (11/22) in which migment granules use microtubules [figure 18-29a & b ]
• Intermediate filaments


  -"rope"

  -Example: keratin filaments (associated with desomosomes)

  -unpolarized

  -cell and tissue integrity

  -won't snap, so not usually very dynamic

  -5 groups
• 5 groups of intermediate filaments

  1. lamins

  2. acidic keratins

  3. basic keratins

  4. Desmin, GFAP, vimentin

  5. Neurofilaments (NFL, NFM, and NFH)

  see table 18-1
• lamins


  -Lamin A.B.C. nucleus

  -phosphorylation of lamin B triggers mitosis
• epidermolysis bullosa simplex


  -sloughing off of skin and shearing skin when touched.

  - rare genetic disease from defective intermediate filaments

  -Dr. Eisenberg created treatment
• Dr. Eisenberg


  -Australian general practicioner who created drug ortec since his son had Epidermolysis bullosa simplex

  -found he could create substitute skin cells from infant foreskins and delivers them to the collagen matrix.
• ortex/OrCel


  -Commercialized treatment for Dr. Eisenbergs method of treating epidermolysis bullosa simplex
• Actin


  -makes up 10% of muscle cells

  -all other cells makes up 1-5%

  -is a major protein

  -filaments required for phagocytosis