cells

prokaryotes

prokaryotes

• no membrane-bound organelles

• unicellular

• domains: bacteria and archaea

eukaryotes

• membrane- bound organelles

• uni- or multi- cellular

• domain eukaryota

  • animals

  • plants

  • fungi

  • protista

nucleus

• contains genetic information in the form of chromosomes or chromatin

• has nucleolus for ribosome production

• surrounded by phospholipid nuclear membrane (envelope)

cytoplasm

• ”Jelly goo” that is within the cell membrane

• Has organelles/ structures in it

• Also found in prokaryotes

ribosomes

• Structures that build proteins during protein synthesis

• Free-floating or attached to the rough ER

• Also found in prokaryotes

rough ER

• Help with protein production and shipping

• Have ribosomes attached

smooth ER

• Synthesis of lipids

• Detoxification

• Storage of calcium ions

golgi apparatus

• “Warehouse” for receiving, sorting, and shipping of proteins

vesicles

• Small “containers” made from ER or golgi membrane that move products around the cell

vacuoles

• Large vesicles for storing products

• Plant cells have a large one filled with water

lysosomes

• Digestive organelle where larger molecules are broken down

• Contain hydrolytic enzymes

mitochondria/mitochondrion

• Site of cell respiration

• ATP is generated

• Found in both plants AND animals

chloroplast

• Site of photosynthesis

• Converts energy from the sun into sugar molecules

• Plants/algae only

centrosome

• Helps with cell division (mitosis) in animal cells

• Contain centrioles

cytoskeleton

• Reinforces cell’s shape

• Helps with cell movement

• Includes:

  • MicrofilamentsIntermediate

  • filaments

  • Microtubules

cell (plasma) membrane

• Found in plants, animals, and prokaryotes

• protection for cell

• fixed environment for cell

cell wall

• Protects, maintains shape, helps with structure

• Made of cellulose

• Found in plant cells and some prokaryotes

cilia (cilium)

• Short appendages containing microtubules present on some eukaryotes

• Used in locomotion

flagella (flagellum)

• “Tail-like” appendage found on some eukaryotes

• Used in locomotion

what determines cell function?

• size, shape, surface area

• organelles present or absent

• quantity of different organelles

endosymbiotic theory (endosymbiosis)

1. Mitochondria and chloroplasts were once free-living prokaryotes engulfed by an early ancestor of eukaryotic cells

2. The engulfed cell formed a relationship with the host cell

3. Over the course of evolution, merged into a single organism

osmosis

• Diffusion of water

• Movement down its concentration gradient: from where there is more water (less solute) to less water (more solute)

• “Water wants to even things out”

hypotonic

less solute, more water

hypertonic

more solute, less water

isotonic

same amount of solute and water

water potential

• Solute potential + pressure potential

  Ψ = Ψp + Ψs

• Water moves from regions of high water potential to regions of low water potential.

solute potential

determined by solute concentration; always negative

pressure potential

pressure from membranes/walls; can be positive or negative

The molar concentration of a sugar solution in an open beaker* is 0.3M.

Calculate the water potential at 27 degrees C. Round your answer to the nearest hundredth.

-1 (0.3 M) x (0.0831L bars/mole K) x (300)

-7.48 bars of solute potential

Phospholipid bilayer structure

• Hydrophilic head

• Hydrophobic tails

• Amphipathic

Proteins

• Peripheral proteins: bound to surface of membrane

• Integral proteins: penetrate hydrophobic core

  • Transmembrane proteins: span entire membrane

carbohydrates (in the cell)

• Glycoproteins: oligosaccharides bonded to proteins

• Glycolipids: oligosaccharides bonded to lipids

• Both help with cell-to-cell recognition

steroids

• Cholesterol: regulates cell membrane fluidity

diffusion

• Movement of particles from area of high concentration to low concentration

• Movement down its concentration gradient

• Does not require energy

Diffusion through the phospholipid bilayer

• passive transport

• no additional energy required

• Small, nonpolar (hydrophobic) molecules

facilitated diffusion through transport proteins

• passive transport

• no additional energy required

• Can move larger, polar molecules

• 2 types of transport proteins

  • Channel proteins

  • Carrier proteins

active transport

• additional energy (ATP)

• Moves substances against their concentration gradients through transmembrane protein

bulk transport

• Moves large molecules across cell membrane

• additional energy (ATP)

• Molecules packaged in transport vesicles (phospholipid “containers”)

exocytosis

• additional energy (ATP)

• moving molecules from inside to outside cell membrane

• Vesicle fuses with cell membrane, releases contents outside

endocytosis

• moving molecules from outside to inside cell membrane

• New vesicle formed of cell membrane containing molecules to be moved inside

• energy required (ATP)

What is the solute potential (Ψs) of a 0.5M sugar solution at 22 degrees Celsius under

standard atmospheric conditions, Ψp=0 Bars

-12.3 bars

The value for Ψ in a potato tissue was determined to be -3.3 bars. If you the potato
tissue and place it in a 0.1 M solution of sucrose at 20 degrees Celsius in an open
beaker, what is the Ψ of the solution and in which direction would the new flow of
water be? If you used a 0.1M solution of NaCl instead of sucrose, in which direction
would the new flow of water be?

-2.43 bars; water will flow into the potato tissue; with NaCl, water will flow out of the potato tissue

protein production

1.  DNA in nucleus

2. Specific segment/chunk of DNA = gene

3. mRNA built from gene (transcription)

4. mRNA comes out from nucleus via nuclear pore

5. Bound Ribosome clamps onto mRNA, reads in 3 letter words

6. Assembles primary structure of protein (translation)

7. Protein released from ribosome into ER 

8. Protein modified in ER

9.  Goes to golgi apparatus via transport vesicle (little pouch of membrane)

10. Vesicle get "pulled" along via motor proteins on cytoskeletal fibers

11.  Vesicle fuses with golgi membrane, releases protein

12.  Golgi modifies & packages protein

13.  Repackaged in another vesicle

14. Motor proteins take to cell membrane

15. Vesicle fuses to membrane and releases protein via exocytosis