Ch. 3 Cell Organization

Cells and Tissues Carry out all chemical activities needed to sustain life Cells are the building blocks of all living things Tissues are groups of cells that are similar in structure and function

Anatomy of the Cell Cells are not all the same All cells share general structures All cells have three main regions NucleusCytoplasm Plasma membrane Figure 3.1a

The Nucleus Function: Control center of the cell Contains genetic material (DNA)

The Nucleus Figure 3.1b

The Nucleus Nuclear envelope (membrane) Structure: Consists of a double membrane Function: Barrier of the nucleus Contains nuclear pores that allow for exchange of material with the rest of the cell

Plasma Membrane Structure: Double phospholipid layer Hydrophilic heads Hydrophobic tails Function: regulate what goes into and out of cell

Plasma Membrane Figure 3.2

Cytoplasm Definition: the material outside the nucleus and inside the plasma membrane Contains three major elements Cytosol Fluid that suspends other elements Organelles Metabolic machinery of the cell “ Little organs ” that perform functions for the cell Inclusions Chemical substances such as stored nutrients or cell products

Cytoplasmic Organelles Figure 3.4

Cytoplasmic Organelles Mitochondria Function: Cellular respiration, providing ATP for cellular energy “ Powerhouses ” of the cell

Cytoplasmic Organelles Ribosomes Structure: Made of protein and RNA Function: Sites of protein synthesis Found in two locations Free in the cytoplasm As part of the rough endoplasmic reticulum

Cytoplasmic Organelles Endoplasmic reticulum (ER) Structure: Fluid-filled tubules for carrying substances Two types of ER Rough endoplasmic reticulum Function: Synthesizes proteins Smooth endoplasmic reticulum Function: lipid metabolism and detoxification of drugs and pesticides

Rough Endoplasmic Reticulum Figure 3.5 Ribosome Protein Protein inside transport vesicle Transport vesicle buds off mRNA Rough ER As the protein is synthesized on the ribosome, it migrates into the rough ER cistern. In the cistern, the protein folds into its functional shape. Short sugar chains may be attached to the protein (forming a glycoprotein). The protein is packaged in a tiny membranous sac called a transport vesicle. The transport vesicle buds from the rough ER and travels to the Golgi apparatus for further processing or goes directly to the plasma membrane where its contents are secreted.

Rough Endoplasmic Reticulum Figure 3.5, step 1 Ribosome Protein mRNA Rough ER As the protein is synthesized on the ribosome, it migrates into the rough ER cistern.

Rough Endoplasmic Reticulum Figure 3.5, step 2 Ribosome Protein mRNA Rough ER As the protein is synthesized on the ribosome, it migrates into the rough ER cistern. In the cistern, the protein folds into its functional shape. Short sugar chains may be attached to the protein (forming a glycoprotein).

Rough Endoplasmic Reticulum Figure 3.5, step 3 Ribosome Protein Transport vesicle buds off mRNA Rough ER As the protein is synthesized on the ribosome, it migrates into the rough ER cistern. In the cistern, the protein folds into its functional shape. Short sugar chains may be attached to the protein (forming a glycoprotein). The protein is packaged in a tiny membranous sac called a transport vesicle.

Rough Endoplasmic Reticulum Figure 3.5, step 4 Ribosome Protein Protein inside transport vesicle Transport vesicle buds off mRNA Rough ER As the protein is synthesized on the ribosome, it migrates into the rough ER cistern. In the cistern, the protein folds into its functional shape. Short sugar chains may be attached to the protein (forming a glycoprotein). The protein is packaged in a tiny membranous sac called a transport vesicle. The transport vesicle buds from the rough ER and travels to the Golgi apparatus for further processing or goes directly to the plasma membrane where its contents are secreted.

Cytoplasmic Organelles Golgi apparatus Function: Modifies and packages proteins Produces different types of packages Secretory vesicles Cell membrane components Lysosomes

Figure 3.6 Extracellular fluid Plasma membrane Golgi vesicle containing membrane components fuses with the plasma membrane Golgi vesicle containing digestive enzymes becomes a lysosome Proteins in cisterna Lysosome fuses with ingested substances Membrane Transport vesicle Pathway 3 Pathway 2 Secretory vesicles Pathway 1 Golgi apparatus Golgi vesicle containing proteins to be secreted becomes a secretory vesicle Cisterna Rough ER Proteins Secretion by exocytosis

Figure 3.6, step 1 Extracellular fluid Plasma membrane Proteins in cisterna Membrane Golgi apparatus Cisterna Rough ER

Figure 3.6, step 2 Extracellular fluid Plasma membrane Proteins in cisterna Membrane Transport vesicle Golgi apparatus Cisterna Rough ER Pathway 1

Figure 3.6, step 3 Extracellular fluid Plasma membrane Proteins in cisterna Membrane Transport vesicle Golgi apparatus Cisterna Rough ER Pathway 1

Figure 3.6, step 4 Extracellular fluid Plasma membrane Proteins in cisterna Membrane Transport vesicle Secretory vesicle Pathway 1 Golgi apparatus Golgi vesicle containing proteins to be secreted becomes a secretory vesicle Cisterna Rough ER

Figure 3.6, step 5 Extracellular fluid Plasma membrane Proteins in cisterna Membrane Transport vesicle Secretory vesicles Pathway 1 Golgi apparatus Golgi vesicle containing proteins to be secreted becomes a secretory vesicle Cisterna Rough ER Proteins Secretion by exocytosis

Figure 3.6, step 6 Extracellular fluid Plasma membrane Proteins in cisterna Membrane Transport vesicle Pathway 2 Golgi apparatus Cisterna Rough ER

Figure 3.6, step 7 Extracellular fluid Plasma membrane Proteins in cisterna Membrane Transport vesicle Pathway 2 Golgi apparatus Cisterna Rough ER

Figure 3.6, step 8 Extracellular fluid Plasma membrane Golgi vesicle containing membrane components fuses with the plasma membrane Proteins in cisterna Membrane Transport vesicle Pathway 2 Golgi apparatus Cisterna Rough ER

Figure 3.6, step 9 Extracellular fluid Plasma membrane Proteins in cisterna Membrane Transport vesicle Pathway 3 Golgi apparatus Cisterna Rough ER

Figure 3.6, step 10 Extracellular fluid Plasma membrane Golgi vesicle containing digestive enzymes becomes a lysosome Proteins in cisterna Membrane Transport vesicle Pathway 3 Golgi apparatus Cisterna Rough ER

Figure 3.6, step 11 Extracellular fluid Plasma membrane Golgi vesicle containing digestive enzymes becomes a lysosome Proteins in cisterna Lysosome fuses with ingested substances Membrane Transport vesicle Pathway 3 Golgi apparatus Cisterna Rough ER

Figure 3.6, step 12 Extracellular fluid Plasma membrane Golgi vesicle containing membrane components fuses with the plasma membrane Golgi vesicle containing digestive enzymes becomes a lysosome Proteins in cisterna Lysosome fuses with ingested substances Membrane Transport vesicle Pathway 3 Pathway 2 Secretory vesicles Pathway 1 Golgi apparatus Golgi vesicle containing proteins to be secreted becomes a secretory vesicle Cisterna Rough ER Proteins Secretion by exocytosis

Cytoplasmic Organelles Lysosomes Function: Contain enzymes that digest worn-out or non-usable materials within the cell

Cytoplasmic Organelles Cytoskeleton Function: Provides the cell with an internal framework Figure 3.7a

Cell Diversity Figure 3.8a

Cell Diversity Figure 3.8b

Cell Diversity Figure 3.8c

Cell Diversity Figure 3.8d

Cell Diversity Figure 3.8e

Cell Diversity Figure 3.8f

Cell Diversity Figure 3.8g