Chapter 4:
General Features of Cells Supplemental Instruction
Iowa State University / Leader: / Adam
Course: / Biology 212
Instructor: / Emeka Kemdirim
Date:

Cell Theory:

·  All

· 

·  New cells come from pre-existing cells by division

Cytosol:

·  Region of the cell outside the membrane bound organelles, but still within the plasma membrane.

·  Many take place here

·  - break down of macromolecules to single monomers

·  Anabolism-

·  The three different cytoskeletons

Cytoskeleton

  1. Intermediate filaments

1.  Microtubules

ü  Function:

ü  Consists of alpha and beta

ü 

ü  Dynamic instability- deterioration of hollow tube.

ü  Grow out of

2.  Intermediate Filament

ü  Function: cell shape, cell tensile strength (allows cell to maintain stress

ü  ex: Skin Cell, smooth muscle cell, axons of nerve cells

3.  Actin Filamenets

ü  Function:

ü 

Nucleus:

·  Enclosed in a double membrane called nuclear envelope.

·  The nuclear envelope is an extension of the same membrane that forms the ER, thus

·  Nuclear pores in the nuclear membrane allow small molecules and proteins to move in and out.

·  Nucleolus-

Endoplasmic Reticulum

·  Flatten fluid filled tubes named Cisternae.

· 

Rough Endoplasmic Reticulum (RER)

·  Outer surface

·  Function:

o  Sorts proteins and sends them to the correct organelle. This is accomplished by glycosylation. Which is the attachement of a Carbohydrate to protein or lipid. (also occurs in golgi app)

o  Last function is

Smooth Endoplasmic Reticulum (SER)

·  Function: Detoxification, Carbohydrate metabolism, Calcium ion storage, synthesis and medication of lipids

Golgi Apparatus

·  Directs processing (proteolysis) protein sorting, and secretion of molecules

·  Golgi side near the ER is termed ______, the membrane side near the plasma membrane is termed ______.

·  Material is transported through stacks of flatten membrane by vesicles.

·  When material reaches trans side, the material in package in ______.

- (materials leaving cell) secretory vesicles fuse with plasma membrane and contents released to outside.

Endocytosis-

Secretory pathway- proteins move from _____ to golgi to vesicle to plasma membrane.

Lysosomes:

·  Function:

·  Breakdowns old organelles to “recycle” material through a process called autophagy

Peroxisomes:

·  Small organelle specialized in catalyzing certain reactions, typically the breakdown of molecules.

Vacuoles

·  Function: storage

· 

Plasma Membrane

·  Selectively permeable

·  Allows cell signaling (detect environmental changes and communicate with other cells). Has receptors that accomplish this by recognizing signaling molecules.

·  - protein protein interaction that allow a multicellular function

Semiautonomous organelles

·  Mitochondria and chloroplast

·  Can

·  Still depend on other organelles