unit 2: cell structure and function

need to edit water potential things

prokaryote (dna)

naked + circular dna; no introns

eukaryote (dna)

protein-bound + linear dna; has introns

prokaryote (organelles)

no nucleus; not membrane-bound; 70S ribosomes

eukaryote (organelles)

has nucleus; membrane-bound; 80S ribosomes

prokaryote (reproduction)

binary fission; haploid (single chromosome)

eukaryote (reproduction)

mitosis + meiosis; diploid (paired chromosomes)

nucleus

holds DNA; chromatin; nucleolus

nucleus (photo)

chromatin

site of transcription; dna to rna; in nucleus

nuclear envelope

lipid bilayer surrounded nucleus; continuous with the ER

nuclear pore

gateway into the nucleus

nucleoplasm

protoplasm within the nucleus

cytoplasm

protoplasm outside the nucleus

nucleolus

site of ribosome biogenesis/creation; in the nucleus

nucleolus (photo)

ribosome

site of translation; made of protein + rna; large + small sub-unit

ribosome (photo)

ribosome (location)

in cytoplasm, rough ER, mitochondria, + chloroplast

endoplasmic reticulum

rough + smooth component

endoplasmic reticulum (photo)

rough ER

many ribosomes; synthesis of proteins (sealed + excreted)

smooth ER

few ribosomes; synthesis of carbohydrates, lipids, + steroid hormones; detoxification

golgi apparatus

distributes lipids + proteins; cis face receives; trans face releases; macromolecules sorted, tagged, + packaged through the cisternae

golgi apparatus (photo)

lysosome

disposal of proteins, polysaccharides, lipids, nucleic acids, + organelles; low pH enzymes (acidic)

lysosome (photo)

vesicle

membrane sacks for storage + transport; connects the endomembrane system

vesicle (photo)

endomembrane system

organelles that modify, package, + transport lipids/proteins; nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, + cell membrane

endomembrane sequence

(dna) → transcription → (rna) → nuclear pore → cytoplasm→ rough ER’s ribosome (protein synthesis) → (protein) → cis-golgi → trans-golgi → vesicle storage

mitochondria

creates ATP (cellular respiration)

mitochondria (photo)

chloroplast

plant; creates glucose via photosynthesis

chloroplast (photo)

endosymbiosis theory

mitochondria + chloroplast were prokaryotes that joined eukaryotes

vacuole

for storage; mostly water + enzymes; very large

vacuole (photo)

cytoskeleton

made of microfilaments (actin), intermediate filaments (fibrous proteins; most permanent), + microtubules (hollow tubulin cylinders)

phospholipids

polar phosphate head; 2 non-polar fatty acid tails

micelle

single layer sphere of phospholipids

liposome

hollow bilayer sphere of phospholipids

peripheral proteins

attach to cell membrane surface; temporary

integral proteins

stick to hydrophobic region of cell membrane; permanent

transmembrane

integral protein on both side of membrane

monotopic

integral protein on one side of membrane

channel

transmembrane integral protein; facilitates movement of material across membrane

glycoproteins

protein + carbohydrate; receptor molecule + cell recognition

glycolipids

lipid + carbohydrate; receptor molecule + cell recognition

cholesterol

reduces effects of temperature on membrane fluidity

permeable (through cell membrane)

small uncharged molecules

slightly permeable (through cell membrane)

small polar molecules

not permeable (through cell membrane)

large or charged molecules

concentration gradient

different concentrations of a substance across a space; substance wants to reach equilibrium (go from high concentration to low)

passive transport

follows concentration gradient; no energy needed

facilitated diffusion

passive transport; uses integral proteins

aquaporin

channel protein for water

carrier protein

integral protein open on only one side of membrane at a time; slower diffusion; selective

active transport

against concentration gradient; energy needed

pumps

carrier protein; moves substance against concentration gradient; uses ATP

uniporter

carries one molecule/ion

symporter

carries two molecules in the same direction

antiporter

carries two molecules in the opposite directions

primary active transport

uses ATP

secondary active transport

uses electrochemical gradient

phagocytosis

intake of food/pathogen; need lysosome to break down

pinocytosis

intake of small molecules; don’t need lysosome to break down

receptor-mediated endocytosis

receptor protein captures target molecule

exocytosis

expels material from cell; vesicle joins membrane

endocytosis

membrane forms vesicle around molecule to bring it into cell

solution

liquid mixture where a minor component (solute) dissolves into a major component (solvent)

osmosis

movement of water across a semipermeable membrane based on the concentration gradient

osmolarity

solute concentration of a solution

human osmolarity

0.3M

tonicity

comparison of the osmolarity of two solutions separated by a semipermeable membrane

hypertonic

higher external osmolarity

isotonic

equal osmolarity

hypotonic

lower external osmolarity

animal cells (tonicity)

hypertonic: shrivels; isotonic: perfect condition; hypotonic: swells/cytolysis

plant cells (tonicity)

hypertonic: plasmolysis; isotonic: acceptable condition; hypotonic: full, turgor/rigid

turgor pressure

pressure from cell in hypotonic solution

water potential (Ψ)

pressure potential (Ψp) + solute potential (Ψs); quantifies the tendency of water to move across gradient

solute potential (Ψs)

-iCRT

pressure potential (Ψp)

accounts for other forces affecting the movement of water (like cell walls)

i

ionization constant; how many molecules can the solvent divide into

C

concentration; M, mol/L

R

pressure constant; 0.0831; (L*bars)/(mol*K)

T

temperature; K