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2 comparing prokaryotic and eukaryotic cells
Prokaryotic Cells
-simple single celled organism
-lacks nucleus and any other membrane bound organelle
-DNA found in central part of cell AKA nucleoid
Four components
1) plasma membrane-separates interior from environment
2)Cytoplasm-Jelly like region in cell
3)DNA

4) Ribosomes-they synthesize proteins
-cell wall made of peptidoglycan
-cell wall helps maintain shape, protects and prevents dehydration
-Flagella for motion
-pili to exchange genetic material during reproduction
-fimbriae=protein appedages used to attach to other cells
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3 Eukaryotic Cells
Plasma Membrane
-made of phospholipid (molecule of two fatty acid chains and a phosphate group) bilayer
and embedded proteins
- separates from outside environment
-regulates passage of some substances (organic molecules, ions, water)
- some absorbtion cells membrane's are folded into microvilli (finger like things) used in
small intestine
Cytoplasm
-from membrane to nuclear envelope
-organelles suspended in a cytosol (gel-like cytoskeleton)
- 70-80% water
-semi solid due to proteins in it
-glucose, polysaccharides, amino acids, nucleic acids, fatty acids found here
-ions of sodium, potassium and calcium found here
-metabolic reactions take place such as Protein synthesis
Cytoskeleton
-network of proteins fibers that are the structure of the cell
-Microfilaments=thinnest type of fiber, maintain structure of micoivillli, muscle
contraction
-intermediate filaments= medium diameter, maintain cell shape/anchor organelles, keratin
(strengthens nails hair)
-Microtubules=thickest fiber, hollow, dissolve quickly, guide organelle movement, our
chromosomes to poles, components of flagella and cilia
Centrosome
-near nucleus of animal cells
-functions as microtuble organizing center

-pair of centrioles (cylinder if 9 triplets)
-replicates before cell divides
-pull duplicated chromosomes to opposite ends
Endomembrane System
-in eukaryotic cells
-group of membranes and organelles
-modify, package, transport lipids/proteins
-includes nuclear envelope, lysosomes, vesicles, endoplasmic retculum, golgi apparatus
Nucleus
-most important organelle
-holds dna in form of chromatin
-directs synthesis of ribosomes and proteins
Nuclear Envelope
-double membrane structure
-punctuated with pores that control passage of ions, molecules and rna between
nucleoplasm and cytoplasm
Chromosomes
-in nucleus made up of dna
-every species had specific number of chromosomes
-chromatin=DNA and proteins
-have sections of DNA that encode ribosomal RNA
Endoplasmic Reticulum
-series of interconnected membranous tubules
-modify proteins and synthesize lipids
-rough ER=ribisomes attached to its cytoplasmic surface (studded appearance)
-smooth ER no ribosomes on cytoplasmic surface (synthesize steroids, detox, alcohol
metabolism, storage of calcium
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Ribosomes
-protein synthesis
-clusters or by themselves floating freely in cytoplasm
-attached indside of plasma membrane or outside of ER
-found in all cells
-especiallt found in red blood cells (sythesize hemoglobin)
Mitochondria

-Powerhouse of cell
-make ATP (cells main energy carrying molecule)
-oval shaped, double membrane organelles
-have own ribosomes and DNA
-two phospholipid bilayers that have different roles in cellular respiration
-muscle cells have lots (need energy)
Peroxisomes
-small, round, enclosed by single membranes
-carry out oxidation reactions that break down fatty acids and amino acids
-detoxify poisons AKA alchol
-byproduct=hydrogen peroxide which is contained in these structures so it won't damage
other things
-breaks down hydrogen peroxide with enzymes into water and oxygen
-animal cells have centrioles, centrosomes, and lysosomes (plants don't)
-plants have cell walls, chloroplasts, plasmodesmata, and plastids, large center vacuole
(animals don't)
Chloroplasts
-function in photosynthesis
-have own DNA and ribosomes
-outer and inner membranes
-contain chlorophyll (captures sunligtht)
Central Vacuole
- regulates cell's concentration of water in a changing environment
-provides turgor pressure (pressure of fluid)
-supports cell wall
-deters herbivoy (tastes bad)
-stores proteins in developing seeds
Extracellular Matrix
-made up of release materials (glycoproteins, protein collagen)
-holds cells together to form tissue
-allows cells in tissue to communicate
-EX=blood clotting
Plasmodesamata-junctions between plant cells
Tight junction- watertight seal between two adjacent animal cells, proteins hold this
Desmosomes- only in animal cells, act like spot welds, keeps cells together in a set like
formation in organs and tissues that stretch

Gap junctions- in animal cells, channels between cells that allow for transport of ions
nutrients and communication
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5 Passive Transport
-plasma mebranes= selectively permeable (allow some things in and others not)
-passive transport is most common, doesn't require energy, move from area of higher
concentration to area of lower
-concentration gradient-spec when there is a different concentration of a single substance
Diffusion
-passive, moves until both spaces have equal amount of it
-Extent of the concentration gradient, mass of molecules, temperature, and solvent
density effects the rate of diffusion
Facilitated transport
-moves across with assistance of transmembrane proteins down a concentration gradient
-no use of energy
-attached to protein and then are passed to specific integral proteins and are facilitated
through passage
Osmosis
-diffusion of water
-equal on both sides
"Tonicity describes the amount of solute in a solution
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In a hypertonic solution (the prefix hyper - refers to the extracellular fluid having a higher
concentration of solutes than the cell’s cytoplasm), the fluid contains less water than the
cell does, such as seawater
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This energy is harvested from ATP that is generated through cellular metabolism
Primary active transport
-moves ions across membrane and creates difference in charge
-uses ATP
-at same time ion is moved in, second substance is moved out
Secondary active transport
-uses energy of electrochemical gradient established by primary active transport
-amaino acids and glucose brought into cell
-ATP is formed using hydrogen ion gradients in mitochondrion
Endocytosis-active transport that moves particles (such as large) into a cell
-phagocytosis=large particles taken in cell through engulfing it
-pinocytosis=takes in solutes that the cell needs from he extracellular fluid
-receptormediated=particles bind to proteins into the cell
Exocytosis
-expel material into extracellular fluid
-particle enveloped in membrane fuses with interior of membrane which opens up it to
the extra of the cell; then expelled

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