1 Cell Biology Flashcards
What is the composition of the cell membrane?
Lipid bilayer with protein channels, enzymes, receptors
What is the role of cholesterol in the cell membrane?
Increases membrane fluidity
What is the charge of the inside of the cell versus outside? What maintains this gradient?
Negative inside versus outside
Due to Na/K ATPase transporter
3 Na+ out/2 K+ in
How are glucose, proteins and other molecules transported across the cell membrane?
Via co-transport supported by the Na+ gradient
Components of extracellular fluid?
CATIONS: Sodium - 140 Potassium - 4 Calcium - 5 Magnesium - 2 ANIONS: Chloride - 103 Bicarb - 24 So4-2 - 1 HPO3-3 - 2 Protein - 16 Organic anion - 5
Component of intracellular fluid
CATIONS: Sodium - 12 Potassium - 150 Calcium - 10-7 Magnesium - 7 ANIONS: Chloride - 3 Bicarb - 10 So4-2 - - HPO3-3 - 116 Protein - 40 Organic anion - -
Define desmosomes/hemidesmosomes
Adhesion molecules, which anchor cells
Cell-cell and cell-extracellular matrix
Define tight junctions
Cell-cell occluding junctions - form and impermeable barrier
Define gap junctions
Connexin subunits
Allow communication between cells
Define osmotic equilibrium
Water will move from an area of low solute concentration of higher solute concentration and approach osmotic equilibrium
What are the cell cycles - what occurs during them?
G1 (cell increases in size, checkpoint)
S (protein synthesis, chromosomal duplications)
G2 (cell increases in size, checkpoint)
M (mitosis, nucleus divides)
What is the most variable stage in the cell cycle?
G1 - affected by growth factors
Determines cell cycle length
What are the stages of mitosis?
Prophase - centromere attachment, spindle formation, nucleus disapears
Metaphase - chromosome alignment
Anaphase - chromosome pulled apart
Telophase - seperate nucleus reforms around each set of chromosomes
What is the composition of the nucleus?
Double membrane - outer membrane is continuous with the rough endoplasmic reticulum
Contains DNA
What is the composition of the nucleolus?
Inside the nucleus
No membrane
Ribosomes are made here