Chapter 3 Flashcards
Who concluded that animal tissues are made from cells?
Schwann
Who established that cells arise only from other cells?
Pasteur
Modern Cell Theory (5)
- organisms composed of cells
- cell is the simplest structural & functional unit of life
- cells come from preexisting cells
- organisms structure & function are due to activities of cells
- cells exhibit biochemical similarities
cell growth increases _____more than ____
volume; surface area
plasma membrane (3)
- surrounds the cell
- made of proteins & lipids
- controls passage of material in & out of the cell
purpose of cholesterol in the membrane?
stiffens the membrane & holds phospholipids
purpose of glycolipids in the membrane?
contributes to glyocalyx (carbs coating on the cell surface)
transmembrane proteins (3)
- pass through membrane
- have hydrophobic & hydrophilic regions
- most are glycoproteins
peripheral proteins (2)
- adhere to one face of the membrane
- tethered to cytoskeleton
Functions of membrane proteins (7)
- receptors
- carriers
- second-messenger
- enzymes
- ion channels
- cell identity marker
- cell adhesion molecules
Second messenger system (2 steps)
- chemical binds to surface receptor
2. Triggers changes within the cell that produce a second messenger in the cytoplasm
kinase
adds phosphate groups to enzymes which can either activate or inactivate an enzyme
G protein
intracellular peripheral protein
cAMP vs ATP
cAMP: 1 phosphate group
ATP: 3 phosphate groups
What do transmembrane proteins with pores allow to pass though?
water and dissolved ions
what are the 3 types of gated channels?
- ligand
- voltage
- mechanically
pumps consume _____ in the process
ATP
what contributes to the glycocalyx that acts like an identification marker?
are they unique in everyone?
glycoproteins
yes; except twins
CAMs
- cell adhesion molecules
- adhere cells to other cells and extracelluar material
What does a cell need to grow & survive?
it needs to be mechanically linked to the extracellular material
microvilli (3)
- extensions of membrane
- serves to increase cells surface area
- specialized in absorption
what shorten microvilli?
actin filaments which are centered in each microvilli
cilia
hairlike processes that move mucus around
axoneme (2)
- core of cilia that is the basis of movement
- has 9+2 structure of microtubules
cystic fibrosis
hereditary disease in which cells make chloride pumps, but fail to install them in the plasma membrane
saline layer for cilia
chloride pumps pump Cl- into ECF
flagella (2)
- whiplike structure with axoneme identical to cilium
- longer than cilium
pseudopods
continually changing extensions of the cell that vary in shape & size