chapter 3 review Flashcards
What is the nucleus?
houses DNA and is the control center
what is the cell membrane?
extremely thin and is selectively permeable
made of lipids and proteins (integral and peripheral proteins)
aid in transport
what is the integral protein?
penetrate the hydrophobic core of lipid bilayer
(in cell membrane)
what is the peripheral protein?
not in lipid bilayer, attached to surface of the cell membrane
what does selectively permeable mean?
only allows specific molecules to pass
what is the membrane permeable to?
gases, small lipophilic molecules, and water
what is the membrane impermeable to?
larger, uncharged polar molecules and ions
what is the cytoplasm?
fills the cell
what is the cytoskeleton?
a network of protein filaments& microtubules in cytoplasm
(controls cell shape)
(involved in movement)
what is diffusion?
molecules or ions in a liquid solution or air, move from high to low concentration
what is facilitated diffusion?
substances too large can not pass through the lipid bilayer
(to move down concentration gradient/ they need help of a membrane protein)
what is osmosis?
movement of water across a selectively permeable membrane
what is hypertonic?
a solution with a higher osmotic pressure than body fluids
what is hypotonic?
a solution with lower osmotic pressure
what is filtration?
happens because of hydrostatic pressure, how high or low (i.e; hypo, hyper, or iso)
Molecules are forced through membranes by exerting pressure
what is active transport?
(Against concentration gradient)
particles moved low to high concentration
what is endocytosis?
Process by which cells absorb external material by engulfing in cell membrane
what is pinocytosis?
membrane engulfs droplets containing dissolved molecules from surrounding
what is phagocytosis?
engulfs particles from surrounding
what is receptor mediated mean?
membrane engulfs selected molecules combined w/ receptor proteins
What is exocytosis?
vesicle fuses w/ membrane and releases contents outside of cell
what is trancytosis?
vescular transport from one side of a cell to the other
what is the cell cycle?
series of changes a cell undergoes from the time it is formed until it reproduces
what is interphase?
the cell grows and synthesizes new molecules and organelles
What is G1?
where cells do most of their growing
What is S?
replicates chromosomes and synthesizes DNA molecules
What is G2?
organelle and molecules required for cell division are produced
What is anaphase?
Chromosomes move toward the poles of the spindle
What is mitosis?
divided into 4 phases
(prophase, metaphase, anaphase, telephase)
a single cell divides in 2 identical daughter cells
what is prophase?
separated genetic material
what is metaphase?
spindle fibers attach to centromeres of chromosomes
what is telophase?
chromosomes move in opposite directions so two new cells can form from one
what is cytokinesis?
splitting of cells
what is apoptosis?
cell death
what is differentiation?
dividing of cells change their function
what are stem cells?
cells that can divide and renew themselves over a long time
