Download Chapter 4: General Features of Cells

Chapter 4:
General Features of Cells
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Adam
Biology 212
Emeka Kemdirim
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.
2. Intermediate filaments
3.
1. Microtubules
 Function:
 Consists of alpha and beta

 Dynamic instability- deterioration of hollow tube.
 Grow out of
2. Intermediate Filament
 Function: cell shape, cell tensile strength (allows cell to maintain stress
 ex: Skin Cell, smooth muscle cell, axons of nerve cells
3. Actin Filamenets
 Function:

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.
NucleolusSupplemental Instruction
1060 Hixson-Lied Student Success Center  294-6624  www.si.iastate.edu
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.
EndocytosisSecretory 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