AP Bio

Test 2

Prokaryotic

Referring to organisms that lack a defined nucleus and membrane-bound organelles, such as bacteria and archaea.

Eukaryotic

Referring to organisms that have a defined nucleus and membrane-bound organelles, such as plants, animals, and fungi.

organelle

Specialized subunits within a cell that perform specific functions, such as mitochondria and chloroplasts.

Tight junctions

Proteins that seal animal cells together, much like a seam.

Extracellular matrix

Animal cells only. Works to hold cells together and help with signaling and cell to cell recognition. (immune system)

Plasmodesmata

Channels that connect plant cells together by spanning the primary and secondary cell walls. Allows water, ions and more to pass.

Desmosomes

Proteins that fasten cells together like rivets. Very strong keratin proteins anchor cells together.

Gap Junctions

Similar to plasmodesmata, but animal specific. A pore through which ions, sugars, amino acids, and other small molecules and signals may pass.

Light micoscope

Uses light to illuminate a subject. Low magnification and cost.

Electron microscope

uses electrons to create a view of a specimen. Must coat specimen in metal prior to shooting with electrons. expensive.

Transmission electron microscope

20 view of an interior all feature. High magnification and cost.

Scanning electron micorscope

3d view of a surface. High magnification and cost.

Difference between prokaryotic and eukaryotic cells.

P: no organelles, DNA is circular, bacteria only, single cell.

E: many organelles, cell wall, DNA forms chromosomes, large and often multicellular.

Importance of compartmentalization in Eukaryotic cells

Separations of functions makes cells more efficient and allows organisms to be more complex.

Nucleus

Controls cell activities and hold nucleolus and chromatin.

Difference between animal and plant cells

P: cell wall, large vacuole, chloroplasts

A: lysosomes, flagelle/cilia, centriole/ centrosome, gap junction.

Cell walls

microtubules, intermediate filament, microfilaments

Fluid Mpsaic model

polar heads, non polar tails. Proteins floating in a sea of phosolipids

Integral membrane protiens

embedded in the cell walls.

peripheral membrane protein

only on the surface of the membrane and typically bound to integral proteins.

Passive transport

require no energy. high to low.

Osmosis

diffusion of water from high to low

diffusion

movement of molecule across a membrane without energy input from high to low.

facilitated diffusion

diffusion with the help of an integral membrane protein from high to low. Usually helps polar, large, or charged molecules cross.

isotonic

equal concentration of water to that inside the cell

hypotonic

a solution with a higher concentration of water than the cell interior. Water rushes into the cell. Animal cells burst, plant cells are happy.

hypertonic

a solution with a lower concentration of water outside the cell than in. Water leaves the cell. animal cells shrink, plant cells wilt

active transport

transport of ions and molecules across a membrane using a system powered by ATP

Carrier-mediated transport

type of active transport requiring a pump and ATP

Endocytosis

bringing large objects into the cell by engulfing them. phagocytosis= solids pinocytosis=lipids

Exocytosis

removing things from the cell by merging a vesicle with the cell membrane.

cotransport

pumping one thing (h+) across the membrane using ATP and letting it diffuse back into the cell along with something else.

Plasma membrane

composition: phospolipids

structure: polar heads, non polar tails

function: selective barrier