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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
-microfilaments
-intermediate filaments
-microtubules
*centrioles (animals only)
external
-cilia
-flagella

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

photosynthesis

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

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