CH. 6-7

Types of microscopes

Electron Microscope (EM)- focuses a beam of electrons through the specimen or onto its surface.

Scanning Electron Mircroscope (SEM)- is useful for detailed study of the tropography of a specimen. The end result is that the image of the specimens surface appears three- dimensional.

Light Microscope (LM)- visible light is passed through the specimen and then through glass lenses

Transmission Electron Microscope (TEM) - is used to study the internal structure of cells. It uses an electromagnet as a lenses to bend the paths of the electrons. TEM aims an electron beam through a very thin section of the specimen.

All organelles structure and function

Plant Cell

Animal Cell

Golgi Apparatus- organelle active in synthesis, modification, sorting, and secretion of cell products

Ribosomes-( small brown dots): complexes that make proteins,free in cytosol or bound to rough ER or nuclear envelope

Lysosome- digestive organelle where macromolecules are hydrolyzed.

Plasma Membrane- membrane enclosing the cell

Mitochondrion- organelle where cellular respiration occurs and most ATP is generated

Nucleus:
Nuclear envelope- double membrane enclosing the nucleus; perforated by pores; continuous with ER
Nucleolus- non membranous structutre involved in production of ribosomes; a nucleus has one nucleoli
Chromatin- material consisiting of DNA and proteins; visible in a dividing cell as individual condensed chromosomes

Peroxisome- organelle with various specialized metabolic functions; produces hydrogen peroxide as a by-product and then converts it to water.

Endoplasmic Reticulum (ER): network of membranous sacs and tubes; active in membrane synthesis and other synthetic and metabolic processes; has rough and smooth regions

Microvilli- projections that increase the cells surface area.

Cytoskeleton-reinforces the cells shape; functions in cell movement and components are made of protein. Includes
Microfilaments- ( actin filaments ) tension baring elements
Intermediate filaments- anchorage of the nucleus and certain other organelles
Microtubles- maintenance of cell shape ( compression- resisting girders

Centrosome- region where the cell's microtubules are initiated: contains a pair of centrioles

Flagellum- motility structure present in some animal cells, composed of a cluster of microtubules within an extension of the plasma membrane

Cell wall- outer layer that maintains cell's she and protects the cell from mechanical damage; made of cellulose' other polysccarides, and protein

Plasmodesmata- cytoplasmic channels through cell walls that connect the cytoplasms of adjacent cells

Plasma Membrane- membrane enclosing the cell

Chloroplast- photosynthetic organelle, converts energy of sunlight to chemical energy stored in sugar molecules

Peroxisome- various specialized metabolic functions

Mitochondrion- cellular aspiration and ATP is generated

Central Vacuole- prominent organelle in older plant cells; functions include storage, breakdown of waste products, and hydrolysis of macromolecules; enlargment of the vacuole is a major mechanism of plant growth

Golgi Apparatus- active in synthesis, modification, sorting and secertion

Ribosomes- ( small brown dots): complexes that make proteins,free in cytosol or bound to rough ER or nuclear envelope

Smooth ER- the ouster surface lacks ribosomes

Rough ER- is studded with ribosomes on the otter surface of the membrane and thus appears rough through the electron microscope

Nucleus- contains most of the genes in a eukaryotic cell

Cytoskeleton- reinforces the cells shape

Cell Fractionation- is a technique for studying cell structure and function by taking cells apart and separating major organelles and other sub cellular structures from each other.

Surface Area- volume ratio- i.e. the amount of surface area per unit volume of an object or collection of objects

Plasma Membrane- functions as a selective barrier that allows passage of enough oxygen, nutrients, and waste to service an entire cell

Membrane Protein functions- do signaling , involved in diffusion,
-Transport protein
-Receptor
-identitiy marker
-enzyme
-anchoring site
-cell adhesion

Prokaryotes Structure- their DNA is concentrated in the Nucleiod
-usuallly smaller that eukaryotes
-membrane bound organelles are usually absent in prokaryotes

Eukaryote Structure- most of its DNA is located in the Nucleus
-Are generally bigger that prokaryotes
-within the cytoplasm are a variety of organelles of specialized form and function.

Diffusion- The moment of particles of any substance so that they spend out into the available space .

Simple Diffusion- small and non polar substances move between phospholipid molecules of the plasma membrane
Facilitated Diffusion- small, charged, or polar substances move assisted by a transport protein

osmosis- water moves from an area of higher to lower free water water concentration

Active Transport-the movement of ions or molecules across a cell membrane into a region of higher concentration assisted by enzymes and requiring energy.

Primary Active transport -pumps are powered directly by splitting an atp molecule .

Tonicity- the ability of a surrounding solution to cause a cell to gain or lose water

Hypertonic- (means more)the concentration of solutes is greater inside the cell than outside of it

Hypotonic- (means less)less solute and more water than another solution.

Isotonic- (means same) if the solutions outside of the is equal to the concentration of solutes inside the cell.

Secondary Active Transport -Pumps are powered by energy harnessed as a second substance moves through a channel down a concentration gradient
Symport - two substances are moved in the same direction
Antiport - Two substances are moved in opposite directions.