Chapter 1 - Cell Biology Flashcards
Cell membrane can be described as?
A lipid bilayer that contains protein channels, enzymes and receptors
Cholesterol does what for the membrane?
Increases membrane fluidity
The inside of the cell is + or - to outside and based on what?
Negative, Na/K ATPase (3Na+ out/2K+ in)
The Na+ gradient across a cell membrane is used for what?
Cotransport of clugose proteins and other molecules
Extracellular fluid plasma cations: Sodium, Potassium, Calcium, Magnesium?
Na+ 140, K+ 4, Ca2+ 5, Mg+2. 40% of TBW. Na is main driver.
Intracellular cations: Sodium, Potassium, Calcium, Magnesium?
Na+ 12, K+ 150, Ca2+ 10(-7), Mg+7. 60% TBW. K is main driver.
Extracellular plasma anions: Chloride, bicarb, SO4 2-, HPO4 3-, Protein, Organic Ions?
Cl- 103, HCO3 24, SO4 1, HPO4 2, Protein 16, Organic anions 5
What are desmosomes/Hemidesmosomes?
Adhesion molecules (cell-cell and cell-extracellular matrix), which anchor cells. IgG (type 2) to desmogleins causes pemphigous vulgaris - mucocutaneous blistering, tx w/ steroids. Can be tx like burn.
What are tight junctions?
cell-cell occluding junctions and form an impermeable barrier (ie epithelium)
What are Gap junctions?
They allow communucation between cells (connexin subunits)
What are G-Proteins?
Intramembrane proteins, transduce signal from receptor to response enzyme. Ex. Activates cAMP for ADH, TSH, PTH, calcitonin, glucagon.
What are ligand triggered protein kinases?
receptor and response enzyme are a single transmembrane protein
ABO blood type antigens are what type of antigen?
Glycolipids on cell membrane
HLA-type antigens are what type of antigen?
Glycoproteins on cell membrane
This cell cycle type is the most variable and determines cell cycle length?
G1 (first growth phase)
Growth factors affect the cell during what phase?
G1
What happens during prophase (first step in mitosis “M” phase)?
Centromere attachment, spindle formation, nucleus disappears
What happens during metaphase?
chromosomes align
What happens during anaphase?
chromosomes pull apart
What happens during telophase?
A separate nucleus reforms around each set of chromosomes