AP bio Cells part 2

Passive transport

movement from high to low concentration across semi-permeable membrane (small things can pass)

no energy required

small non polar molecules pass through membrane

or channel proteins allow ions or polar molecules to cross the membrane

Diffusion

the passive transport of molecules across a semipermeable membrane

small non-polar molecules

high to low

osmosis

is the diffusion of water (in the opposite direction of the solute)

ficilitated diffusion

ficilitated= “helped” (via membrane proteins)

diffusion = no ATP required

larger or polar/charged molecules use carrier proteins or channel proteins

hight to low

channel proteins

channel proteins are a channel which water molecules go through. channel proteins allow speccific molecules or ions to cross the membrane.

carrier proteins

carry the ion/molecules across the membrane by changing shape when ion or molecule binds

water through a membrane

because water is small it can pass through the membrane however it moves slowly because of its polar charge

water used aquaporins b/c its polar

water potential

pure water = 0 bars

water is always going to move from high to low water potential

determines weather water will move into or out of a cell

Tonicity

relative measure of solution concentration

Hypotonic

low solute content more water content outside the cell so water goes into cell (bad for animal cells good for plant cells)

isotonic

equal solute inside and outside cell (equal water goes in and equal water goes out of cell) this is normal for animal cells less normal for plant cells so plant is a little less turgid.

simplistic math

water goes from high to low concentration. If the water concentration in the cell is 90% and outside the cell is 100% then water will enter

Hypertonic

high solute content and less water content outside the cell so water goes out of cell. Bad for both animal and plant cells. plant cells become very floppy because there’s less turgor pressure. animal cells become shriveled.

Bulk transport

active transport

moving big stuff

endocytosis and exocytosis

endocytosis

intake of large molecules

the cell membrane pinches around large molecules outside the cell and creates a new vesical

exocytosis

Release/ exiting of large cellular products/wast

A vesicle from the golgi gets transported to the cell membrane. the vesicle membrane and cell membrane fuse and the contents get dumped from the cell.

2nd law of Thermodynamics

chaos increases unless energy is added

living thing adds energy via food/sunlight to maintain organization.

Active transport

Movement from low to high concentration

uses membrane proteins and ATP

charged phosphate group changed the protein structure

for moving large molecules (exo or endo)

low to high

the cytoskeleton

a network of structural proteins that extends throughout the cytoplasm

function is structural support, maintaining cell shape and anchorage of organelles

cilia

function: movement of cell through space

small and large in number

Structure: extension of the cytoskeleton protiens

Flagella

function: movement of cell through space

long but only 1-3 in number

Structure: extension of the cytoskeleton proteins

Plasma membrane

phospholipid bilayer

“The Fluid Mosaic Model”- proteins float around the constantly changing membrane like icebergs on the ocean

Function: boundary of cell, transports materials in and out, communication between cell and environment

selectively permeable

small, non-polar molecules can pass through

intergral proteins

pentetrate both layers of the phospholipid bilayer or the membrane

Peripheral proteins

onn top of the cell or stuck to the bottom of the cell but don’t pentetrate both sides of the bilayer.

how do proteins stay in place in the membrane

the polarity of different parts of the membrane protein vary according to the location of that protein. the polar part of the protein will be by the polar heads and the non-polar parts of the protein will be by the non-polar tails

cholesterol

steriod Lipids that change the fluidity of the membrane

makes the membrane less fluid at warmer temps and more fluid at lower temps

glycolipids

structure: have a polysaccharide attached

Function: cell recognition

important in cell recognition

glycoproteins

Structure: intergral proteins that span the bilayer with short polysaccharides, residues projecting extracellularly into the environment

Function: cell-cell recognition, identifying marker in cellular populations

EMC

important in cell anchorage

Structure: a network of connective proteins and “proteglen” molecules outside of the cell membrane of animal cells

Function: cell anchorage, cell communication

centrioles/centrosome

found in animal-like cells

Structure: barrel shaped organelles found at right angles to one another; made of microtubules

Function: separate chromosomes during cell division.

pH

Has to do with the H+ ions

the greater the H+ ions the lower the pH

the lower the H+ ions the greater the pH

Glucose

larger polar molecules

The O6 in C6 H12 O6 is what makes glucose polar

phago

eating

phino

dinking

contractile vaculo

stops pumping when the cell is a high concentration and the outside is low concentration

starts pumping really fast when the cell is a low concentration and the outside is a high concentration because the cell needs to pump the water out because water is rushing in.