AP BIO Unit Two

Cell Theory

Cell Theory

All organisms are made of cells, basic unit of life, all cells come from preexisting cells

To be labeled as living there needs to be

reproduction, response to stimuli, growth/development, homeostasis, use of energy

Microscopes where founded by who

Robert Hooke in 1665

What are some of the different types of a microscope

light microscope, transmition electron microscope(TEM), scanning electron microscope(SEM)

Light microscopes are used for

living cells

electron microscopes are used for

dead cells

TEM

used to study internal parts of cells

SEM

lets us see the surface structure of cells

Cell fractionation

separate organelles from cells, variable density of organelles-ultacentrifuge

centrifuge

technique to separate

All cells have

plasma membrane, cytosol, chromosomes, ribosomes

cytosol

semi-fluid substance within the membrane

Prokaryotic

DNA in nucleoid region, w/o membrane separating it from the rest of the cell

Eukaryotic

chromosomes in nucleus, membrane enclosed organells, more complex, generally bigger, cell specialization

Surface are to volume ratio

as cells get bigger its volume increases faster than its surface area, smaller objects have greater ration of surface are to volume, SMALLER cells diffuse faster than LARGER cells

nuclear envolope

pores

Nuclear lamina

a structure near the inner nuclear membrane and the peripheral chromatin

nucleolus

inside the nucleus, makes ribosome components

Endomembrane system

nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vesicles, vaculoles, plasma membrane

Golgi has two sides

cis side- receiving side and trans side- shipping side

Autophagy

lysosomes breaking down damaged organelles

Endosymbiosis

theory that mitochondria and chloroplasts were once prokaryotic that were consumed by eukaryotes and became endosymbiotic

mitochondria

folds in inner membrane increase the surface, no mitochondria=not much energy

Chloroplast

plastid that contains chlorophyll

Peroxisome

contains enzymes that remove hydrogen from various substrates and makes hydrogen peroxide. Prevents cells from harmful toxic substances

Cytoskeleton

functions in structural support for the cell network for fibers that organizes structures and activities within the cell-made of proteins sometimes complex carbohydrates

Cilia+flagella

motile appendages containing microtubules

protein tubes

microtubules

cilia

short usually numerous, hairlike structure

flagella

long, fewer, whip-like structure

Cell Wall

found in plants, bacteria, and fungi

plants

composed of cellulose

bacteria

composed of peptidoglycan

fungi

composed of chitin

cell junctions

neighboring cells often adhere, interact, and communicate via sites of direct contact

plasma membrane

edge of living/nonliving, structure determines function, selectively permiable

amphipathic

has both a hydrophobic and hydrophilic region

membranes are bifacial

they have distinct inside and outside faces

proteins on the outside of membranes are unstable

not soluble in water they are amphipathic

integral proteins

at least partially into hydrophobic areas

peripherial proteins

not in hydrophobic region

cholosterol

lipid, steroid

carbohydrate

only on extracellular side(outside)

glycoprotein and glycolipids

cells are structured by what

matrixs(nonliving stuff)

temp the membrane solidifies at

depends on its compostition

cholesterol acts as a

fluidity buffer which resists changes in the membrane due to temp changes

some cells can alter lipid composition of membraneas

cold adapted organisms and prevents membranes from solidifying during winter

the hydrophobic regions of an intergral protein

consists of one or more stretches of nonpolar amino acids, often coiled into alpha helices

six major functions of proteins in cells

transport, enzyme activity, signal transduction, cell-cell recognition, inter cellular joining, attachment to cytoskeleton and extracellular matrix(ECM)

bifacial

two lipid layers differ in composition, anything w/ a membrane is bifacial

hydrophobic(nonpolar molecules)

such as hydrocarbons, can dissolve in the lipid by layer

polar molecules

sugars cant cross the membrane as easy

carrier proteins

bind to substances and physically move it across the membrane

aquaporins

allows entry of water, passing through single file through its central channel, doesnt bond

passive transport

is diffusion of a substance across a membrane w/ no energy invesment

diffusion

high to low

dynamic equalibrium

many molecules cross one way as they cross in one direction

osmosis

passive transport of water, diffusion of water across a selectively permeable membrane

tonicity

the ability of a surrounding solution to cause a cell to gain or lose water. Based on solute concentration and membrane permeability

hypotonic

solution w/ lower solute concentration compared to inside

isotonic

equal solute concentration on inside and outside

hypertonic

solution w/ greater solute concentration than whats inside

osmoregulation

the concentration of water balance, adaptation

globular proteins

doors in membrane, channel or carrier protein, channels to over specific molecules through cell membrane

ion channels

open or close in response to a stimulus(gated channels- passive transport, bonds to it to open")

Active transport

moves substances against concentration gradient

ion pumps

all cells have voltages across their membranes, electrogenic pumps, protein pumps

cotranspot

a single ATP powered pump that transports a specific solute can indirectly drive the active transport of several other solutes in a mechanism

bulk transport

using vesicles

exocytosis

exit large molecules

endocytosis

enter large molecules

ligand

message receptor, outside membrane

phagocytosis

cell eating

pinocytosis

cell drinking

receptor mediated endocytosis

responding to message