AP Biology Unit 2: Cell Structure and function

1. All living things are made of cells

2. cells are the smallest units of life

3. cells only come from other cells through cell division

Cell Theory

plasma membrane, DNA, cytoplasm, Ribosomes

Prokaryotic and eukaryotic similarities

Nucleoid Region, no membrane bound organelles

prokaryote characteristics

nucleus, membrane bound organelles

Eukaryote characteristics

SA = plasma membrane V= cytoplasm. High SA:V ratio = crammed organelles and faster transport

Why do cells have large SA:V ratio?

low = high concentration of hydrogen ions
high= low concentration of hydrogen ions

pH

flattening, branching, folding, projections

Adaptation to increase SA:V ratio

increase sa:v ratio and absorb water

role of root hairs

Mutualism: fungus absorbs water + minerals, mycorrhizae gets amino acids and sugars

mycorrhizae and fungi role

threads in intestine that help absorb nutrients

microvilli role in inestines

small diameter, folds, microvilli

small intestine adaptations to increase sa:v ratios

membrane bound organelles separate the different jobs, increase efficiency for more complex issues. Small, flat folded and branching cells allow organelles to be squished in max sa:v ratio

why are eukaryotes compartmentalized?

respiratory membrane of bacteria; thylakoid membrane acts as a plasma membrane

compartmentalization in prokaryotes

two independent bacteria exist, one engulfs the other and both live and benefit, reproduce together. Mitochondria and chlorplasts.

theory of endosymbiosis

some organelles have double membranes, reproduction occurs like fission, susceptible to antibiotics

evidence of endosymbiosis

hydrolyze/digest stuff within a cell, apoptosis, dissolving tail/webbing, recycles damaged organelles

lysozome roles

1. stores DNA

2. has nuclear envelope with pores to transport large proteins

3. site of gene expression

nucleus roles

inside nucleus, produces ribosomes

nucleolus

protein synthesis: arrange amino acids

ribosome role

1 large 1 small, made up of rRNA and protein

#of ribosomal subunits and materials needed for synthesis

sythesize secretory proteins, create membrane for transport vesicles

rough er roles

free ribosomes are used in the cytooplasm,

attached ribosomes are attached to rough er and will go to plasma membrane or be secreted out

free vs attached ribosomes

smooth er

lipid synthesis

smooth er

drug detox: filtering blood and detoxing in liver

smooth er

carb metabolism: metabolize glycogen, reduce muscle damage via glucagon hormone

smooth er

calcium ion storage for muscle contractions

1. adds functional groups to proteins e.g phosphate group

2. complete tertiary/quaternary structure

3. packages carbs to synthesize cellulose on site

4. think packaging site

golgi apparatus

The central vacuole:
1. stores water to increase turgor pressure and stretch cells

2. store pigments in petals to attract pollinators

3. store toxins to repel predators

vacuoles: compartments

increase sa:v ratio

purpose of folded inner membranes within mitochondria and chloroplasts

plants, animals, fungi, protists

4 types of organisms that contain mitochondria

same as the site of cell respiration

enzyme location for cellular respiration

light reactions and calvin cycle

components of photosynthesis

same as where light reactions and calvin cycle take place

where are the enzymes for each step of photosynthesis located?

thylakoid membrane

light dependent reaction location

stroma

calvin cycle location

cytoplasm

glycolysis location

mitochondrial matrix

transition reaction and krebs cycle location

inner membrane (cristae)

chemiosmosis/electron transpport chain location

semipermeable

cell wall permeability in plants

plasmodesmata

holes in cell wall that allow for fast exchange of water, minerals, sugars, and other macromolecules between two cells

chitin, semi permeable

chemical composition of fungi cell walls, permeability

septa

partially formed cell wall in fungi that helps transport all polymers except for Dna and Rna

peptidoglycon = AA+sugar combo, semipermeable

chemical composition of bacterial cell walls, permeability

Fluid Mosaic Model

model of cell membranes characterized as dynamic, flexible, and always changing composition. Made up of a ____ of components

laterally

direction that membrane components move

sidedness

referring to how the cytosol and extracellular stuff are different, stuff on either side of the membrane is different

regulate fluidity

cholesterol role in cell membranes

hydrophilic, hydrophobic

phospholipid heads are ____, phospholipid tails are____

false

true or false, the membranes within each organelle and species have the same chemical composition and structure

Too rigid= not enough transport, too fluid= too much transport

how does fluidity influence transport?

usually for warm temps, makes membrane more rigid

how do the presence of saturated phospholipids impact membrane fluidity?

usually for cold temps, makes membrane more fluid

how do the presence of unsaturated phospholipids impact membrane fluidity?

more cholesterol + unsaturated fats bc of cold, increase fluidity

what would the membrane structure of a fish living in very cold waters look like?

conifers have more saturated fats= adjusting temps

what would the membrane structure of a tree living in changing temps look like?

Transport proteins: send substances in and out of cells

what protein, what purpose?

Enzymatic Proteins: make cellulose, ATP, chloroplasts

what protein, what purpose?

Signal Transduction Proteins: cell communications with transmitters and receivers, think insulin

what protein, what purpose?

Glycolipids/Glycoproteins: cell marking/identification, think immune response, blood transfusions, tissue/organ transplants

what protein, what purpose?

Intercellular joining: skin

what protein, what purpose?

Cytoskeleton connection to extra cellular matrix: environment and cytosol are connected via proteins

what protein, what purpose?

1. Smooth er makes lipids

2. Rough er makes proteins

3. Golgi packages lipids and proteins

where are cell emmbranes built and modified?

transport large ions through facilitated diffusion

transport protein purpose

true

true or false: transport proteins are specific to an ion

Transport proteins can only work so fast, rate increases than plateaus with a limited number of transport proteins, more proteins = more transport

transport protein saturation

moving a nutrient from high to low concentration, no energy

passive transport

different concentration on either side of a membrane vs same concentration

concentration gradient vs equuilibrium

high to low

water flows from ___ to ___ water potentials

decreases, decreases

as solute concentration increases, solute potential _____ which ____ water potential

lipid soluble vitamins, proteins

what will diffuse fastest across a membrane?

their own

each nutrient diffuses down ____ concentration gradient

gases like O2, N2, CO2, small uncharged/nonpolar molecules

what molecules can pass through the lipid bilayer through diffusion, without a transport protein?

an organism’s ability to regulate internal water, e.g kidneys, skin, and large intestine help absorb water and get rid of excess

osmoregulation

water moving from high to low solute concentrations or through facilitated diffusion with transport protein

osmosis

help osmoregulation by allowing freshwater to diffuse into the cell but then being pumped out by vacuole to reduce water pressure. Pumps from low to high.

contractile vacuoles in freshwater paramecium

tonicity

how solutes influence osmosis

normal, red blood cells, body tissues

animal cells in an isotonic solution, examples

flaccid, guard cells close stoma to stop water loss

plant cells in an isotonic solution, examples

crenation (shrivel), high salt concentration in blood draws water from body tissues, increasing blood pressure

animal cells in hypertonic solution, examples

plasmolyzed (large gap between cell membrane and cell wall), excess fertilizer dehydrating lants

plant cells in hypertonic solution, examples

lysed, large intestine epithelium, capillaries designed to absorb water, without regulation it leads to dysentery

animal cells in a hypotonic solution, examples

turgid, root hairs, guard cells open stoma to let water in

plant cells in a hypotonic solution, examples

hypertonic

water moves towards the ____ solute concentration

using transport and carrier proteins to move large molecules from high to low concentration, no energy

facilitated diffusion

channel proteins

funnel ions from one side of a membrane to another, can open and close, used in passive transport

carrier proteins

changes shape to dump ions on other side of membrane, used in active transport

1. water through aquaporins

2. fructoose through channels in small intestine epithelium

3. glucose through muscle,liver, or fat cell channels

examples of substances that diffuse through transport proteins

using a transport protein to pump large substances from low to high concentrations, requires energy supplied by ATP

active transport

1. Sodium (Na) and Potassium (K) ion pumps used in neurons

2. Proton pumps in mitochondria and chloroplasts

examples of active transport

charges of the cytosol and extracellular fluid can impact diffusion

membrane potential

negative, positive

the cytoplasm is usually ___ and the extracellular fluid is usually ___

true

true or false: if a nutrient has a charge it is impacted by membrane potential

1. sodium potassium pump in neurons

2. proton pump in in mitochondria and chloroplasts in plants, fungi, and bacteria

examples of membrane potentials

no concentration gradient

why is energy used for bulk transport, though it is not considered active transport?

a vesicle produced and packaged at the golgi goes to plasma membrane, fuses and dumps nutrients SECRETE

exocytosis

SECRETE

1. pancreas secreting insulin

2. White blood cells secreting antibodies

3. small intestine epithelium secreting enzymes

exocytosis examples

phagocytosis, pinocytosis, receptor mediated endocytosis

types of endocytosis

englufing food particles and creating food vacuoles.

1. lysozomes

2. White blood cell engulfing a virus

3. Amoeba engulfing a bacterium

phagocytosis, examples

using transport vesicles to move fluids into cell. WITHIN EVERY CELL

1. epithelial cells taking in plasma (water minerals and biomolecules of blood)

pinocytosis, examples

target molecule binds to receptor protein

1. Liver cells removing cholesterol from blood, if receptor protein doesn’t work liver will make more cholesterol resulting in hypercholesterolemia

receptor mediated endocytosis, examples

loss of pressure = water is leaving cell

loss of turgidity