ap bio unit 2

why should we study cells

they are the foundation of biology

what system is the body organized into

cells→tissues→organs→ organ systems→ organisms

who discovered the cell and when

Robert hooke, 1665

who saw the living microorganism

anton van leeuwenhoek

who came up with cell theory

schleiden (plant), Schwann (animal), Virchow

what are the 3 parts of cell theory

1. all living things are made up of cells

2. the cell is the basic unit of life

3. cells come from pre existing cells

what are the 2 types of cells

prokaryotic and eukaryotic

what is a prokaryotic cell

no nucleus, no membrane bound organelles, small and simple (bacteria)

what is a eukaryotic cell

nucleus, organelles, larger and complex (plants, animals, fungi, protists)

common features of all cells

• plasma/cell membrane (controls entry/exit)

• cytoplasm (jelly like fluid inside)

• DNA (genetic instructions)

• ribosomes (protein builders)

light microscope

uses visible light, up to 1000x magnification

electron microscope

uses beams of electrons, much higher resolution

when and who discovered the cell

1665- Hooke, Leeuwenhoek

cells must remain ____

small

_______ to ______ ratio is critical

surface area, volume

a large surface area to volume ratio is an _________ exchange of nutrients/waste

efficient

if the cell is too big and inefficient

it cannot support itself

compartmentalization

separation of cellular functions into organelles, increases efficiency and specialization

nucleus structure

double membrane, pores, nucleolus

nucleus function

stores DNA, directs activity, makes ribosomes

function of nucleolus

synthesizes ribosome

function of pores

lets ribosomes out

function of double membrane

security

ribosomes are found in __________

both prokaryotes and eukaryotes

free ribosomes are

proteins for cell use

bound ribosomes (RER) are

proteins for secretion

ribosomes are the

universal feature of life

_____ have different machinery to synthesize ribosome

prokaryotes

rough ER

protein modification

smooth ER

lipid synthesis, detox

golgi apparatus/body

package/ships proteins (and lipid)

vesicles/vacuoles

transport and storage

lysosome

digestive enzymes

aproposis

program cell death

lysosomes are _____ bag of cell

suicidal (hydrolase enzyme)

hydrolytic

break down

lysosomes are present in many ____

numbers

if there are too many lysosomes it ______

self destructs and bursts, destroying what it comes into contact with

mitochondria is surrounded by

a double membrane

mitochondria is the _____ of the cell

powerhouse

mitochondria has its own _____

DNA and ribosomes (semiautonomous)

mitochondria’s energy source is ____

ATP

where is ATP stored in the mitochondria

cristae

where is chloroplasts located

in plants

what are the 2 reactions in chloroplasts

light and dark

where do light reactions take place

grana/thylakoid

where do dark reactions take place

stroma

what is the cytoskeleton composed of

microtubules, microfilaments, and intermediate filaments

what does cyto mean

cell

functions of cytoskeleton 

shape, transport, movement

cytoplasm

material within a living cell enclosed by the cell membrane

what is cytoplasm comprised of

cytosol, organelles, and various inclusions

cytoplasm’s function

act as the site for most cellular activities

3 parts of the cytoplasm

1. cytosol: gel like watery substance 

2. organelles: specialized structures within the cell

3. inclusions: non-membranous structures serving as storage sites for nutrients and other substances

where are peroxisomes located

inside almost all eukaryotic cells

what are perixosiomes 

small membrane bound organelles that help keep the cell safe by breaking down certain harmful substances 

what do peroxisomes break down

hydrogen peroxide

catalase

enzyme peroxisosomes use to convert water into oxygen

centrioles play an essential role in

cell division, organization, and the formation of cilia and flagella

centrioles are only present in

animal cells

shape of a centriole

cylindrical, microtubule arranged at right angles to form the centrosome

what are centrioles built from

9 sets of microtubule triplets arranged in a 9+0 pattern

cilia

hairlike extensions that stick out from the surface of eukaryotic cells

what is cilia and flagella made of

microtubules wrapped in a plasma membrane covering

main job of cilia

movement of the cell itself or materials, anchored by a basal body

arrangement of cilia

9+2, 9 pairs of microtubules in a ring, 2 in center

cell wall is only located in

plant cells

what is the cell wall

rigid structure that provides support, protection, and shape

cell wall is primarily composed of

cellulose, hemicellulose, and pectin

what is the vacuole

membrane bound organelles (tonoplast) that serve essential functions in storage, involvement in digestion/waste removal, and regulating cellular homeostasis

what vacuole do plans have

one big central

what vacuole do animals have

many small

contractile vacuole

osmoregulation regulates amount of water in body (unicellular)

what is the main difference between free and bound ribosomes

free synthesizes proteins within the cell, bound produces proteins for export or incorporation into cell membranes

what is the nucleolus primarily responsible for producing

rRNA and ribosomal subunits

what are cytoskeleton filaments that form spinal fibers to separate chromosomes in mitosis

microtubules

the endosymbiotic origin of mitochondria/chloroplasts evolved from

engulfed prokaryotic cells

what helps maintain cell turgor pressure in plant cells

the central vacuole

free floating ribosomes synthesize proteins that function in the

cytosol

what enabled bacterial cells to adhere to surfaces/exhange DNA

pili

tay Sachs disease is caused by the malfunction of

lysosome

most important for muscle contraction in the cytoskeleton are

actin microfilaments

where is chromatin found 

the nucleus

the order of transport

Rough ER→ Golgi→ transport vesicle → plasma membrane

pancreatic cells secrete proteins needing

rough er and Golgi

phospholipid bilayer is made up of

hydrophilic heads and hydrophobic tails

proteins in the phospholipid bilayer

channels, carriers, receptors

cholesterol in the phospholipid bilayer

keeps membrane fluid

carbs in the phospholipid bilayer

acts as ID tags for cell recognition

what is passive transport

movement without ATP, from high to low concentration

types of passive transport

diffusion, osmosis, and facilitated diffusion

diffusion

molecules lose from high to low concentration, all types

osmosis

only water or solvent membrane move from high to low, selectively permeable membrane

2 types of osmosis

endosmosis: inflow of water (enter)

exosmosis: outward flow of water (exit)

facilitated diffusion

molecules use protein channel to move

tonicity

amount of dissolved substances (solute) in the solution

isotonic

amount of solute outside the cell= amount inside the cell

cell stays the same size because water moves in and out equally

hypotonic

solution outside cell has less solute and more water than inside the cell

cell gets bigger→ water moves into the cell

hypertonic

solution outside the cell has more solute and less water than inside the cell

gets smaller because water moves out of the cell

active transport

requires energy, moves from low to high