A tour of the cell

Cell theory
A. all organisms are composed of one or more cells
B. the cell is the basic unit of organization of organisms
C. All cells come from pre-existing cells
Microscope Parts
1. ocular
2. revolving nosepiece
3. objective lens
4. light source
5. arm
6. course adjustment
7. fine adjustment
8. iris diaphragm
9. base
Surface area: volume
-the surface are of a cell is important for carrying out the cells functions, such as acquiring adequate nutrients and oxygen
-a small cell has more surface area relative to its cell volume and is more efficient
-more surface area + less volume= more efficient
-smaller cells= more efficient
Two types of cells
Prokaryotic (only bacteria)
-no nucleus, no organelles (membrane bound structure)
Eukaryotic (plants, animals, fungi, protozoa)
-nucleus and organelles
Cell membrane structure
phospholipid bilayer w/ proteins dispersed
Nucleus structure
surrounded by a double membrane, nuclear envelope, with pores; contains a nucleolus which produces ribosomes; contains DNA
Cytoplasm structure
thin, fluid-like gelatin
Ribosomes structure
round structures found singly or in groups in the cytoplasm or along the endoplasmic reticulum
Endoplasmic reticulum structure
folded membrane w/ many interconnected compartments
a. rough ER- w/ ribosomes
b. smooth ER- w/out ribosomes
Golgi body (golgi apparatus) structure
S= stacked, flattened membrane
Mitochondria structure
S= oblong w/ folded inner membrane calle cristae to increase S.A. for rxn's: have their own DNA
Lysosome structure
S= small, round, contains enzymes (membrane protects the rest of the cell from being broken down)
Vacuole structure
S= large membrane bound sac
Chloroplasts (plants only) structure
-contains chlorophyll pigment (green)
S= double membrane bound stacks of grana which contain pigment
Cell wall (plants and fungi only) structure
S= surrounds cell membrane; composed of cellulose in plants, chitin in fungi
Cytoskeleton structure
S= internal
-intermediate filaments
*centrioles (animals only)
Cell membrane function
-selectively permeable boundary btwn the inside of the cell and external environment
-maintains homeostasis through diffusion, osmosis and active transport
Nucleus function
control center of the cell; DNA contains the genetic code for all cell functions
Cytoplasm function
fills the cells and suspends organelles
Ribosome function
site of protein synthesis
Endoplasmic reticulum function
transports protein
Golgi body (golgi apparatus) function
packages, addresses and sends proteins for transport within or outside of the cell (Ups)
Mitochondria function
provide energy by breaking down food molecules w/ enzymes
Lysosome function
breaks down old cell plants; kills invading bacteria or viruses; digests food particles
*only in animal cells
Vacuole function
temporary storage of food, enzymes or wastes; fill with water to provide turgor pressure
*central vacuole in plants; large, plant cells fill it w/ water
Chloroplasts (plants only) function
Cell wall (plants and fungi only) function
provides support for the cell and the entire organism
Cytoskeleton function
gives support+shape, allows it to move