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
passive transport does/doesn’t require ATP, while active transport does/doesn’t require ATP
does not; does
examples of passive transport (3)
filtration
diffusion
osmosis
filtration
particles are driven through a selectively permeable membrane by hydrostatic pressure
simple diffusion
the net movement of particles from area of high concentration to low concentration
factors affecting diffusion (5)
- temperature
- molecular weight
- steepness of concentration gradient
- membrane surface area
- membrane permeability
What can diffuse through lipid bilayer? (3)
- nonpolar
- hydrophobic
- lipid-soluble substances
What can diffuse through channel proteins? (3)
- water
- charged
- hydrophilic solutes
how can you increase the rate of osmosis?
aquaporins
osmolarity
of osmoles (particles) of solute per liter of solution
tonicity; what does it depend on?
- ability of a solution to affect fluid volume & pressure in a cell
- concentration & permeability of solute
2 types of carrier mediated transport
- facilitated diffusion
- active transport
transport proteins are ___ for certain ligands
specific
facilitated diffusion (2)
- carrier mediated transport of solute through a membrane down its concentration gradient
- does not require ATP
primary active transport (2)
- carrier moves solute through a membrane up its concentration gradient
- requires ATP
what type of transport is Na-K pump?mechanism?
- primary active transport
- uses 1 ATP and pumps 3 Na(out) for 2 K(in)
carries only one solute at a time
uniport
carries two or more solutes (different) in the same direction
symporter (cotransport)
carries two or more solutes in opposite directiones
antiporter (countertransport)
carrier mediated transport
transport proteins in the plasma membrane that carry specific solutes from one side of the membrane to the other
carrier mediated transport:as the solute concentration ____, the rate of transport _____, but only to a point
rise; rise
purpose of Na-K pump?
to maintain negatively charged resting membrane potential
secondary active transport
carrier moves solute through membrane but only uses ATP indirectly
vesicular transport
moves large particles, liquids, or numerous molecules at once through the membrane in vesicles
endocytosis
bring material into the cell
phagocytosis
engulfing large particles
pinocytosis
taking in droplets of ECF containing molecules useful in the cell
exocytosis
discharging material from the cell
cytoskeleton
collection of filaments and cylinders that determine shape of cells and lead structural support
what is the cytoskeleton composed of?
microtubules
intermediate fibers
microfilaments
what organelle is the largest?
nucleus
what are the organelles in the cell? (6)
nucleus ER golgi complex mitochondria lysosomes peroxisomes
rough ER (4)
- produce phospholipids & proteins of the plasma membrane
- first section continuous with nuclear membrane
- has ribosomes
- flatten cisternae
smooth ER (4)
- lacks ribosomes
- tubular cisternae
- synthesize steroids & other lipids
- detoxifies alcohols & drugs
small granules & RNA
ribosomes
golgi complex (2)
- synthesize carbs
- put finishing touches on protein synthesis (packaging)
where can the vesicles from the golgi end up?
- lysosomes
- fuse with plasma membrane
- become secretory vesicles for later release
lysosomes derive from? function?
- produced my golgi
- intracellular digestion of macromolecules
peroxisomes (2)
- resemble lysosomes, but are not produced by golgi
- produce hydrogen peroxide
hollow cylindrical organelles that dispose of surplus proteins
proteosomes
mitochondria
specialized for synthesizing ATP
where is it thought that the mitochondria originated from?
bacteria
centrioles (3)
- short assembly of microtubules arranged in 9 groups of 3 microtubles
- important in cell division
- make up the centrosomes (2x)
two types of inclusions
- stored cellular products
- foreign bodies
are inclusions essential for cell survival?
NO
