Cell structureCell structure

RibosomeRibosome

Endoplasmic Reticulum-set of interconnected membranes. Forms cisternae. 2 types:

Rough ER - studded with ribosomes that are attached to cytosolic side of rER

Smooth ER- no ribosomes

*Ribosomes formed in nucleolus*

The Endoplasmic ReticulumThe Endoplasmic Reticulum

Endoplasmic Reticulum (ER) - system of tubes and sacs formed by membranes

Rough = modifies proteins produced on the ribosomes. Synthesis of proteins for export from the cell, integral proteins of cell membrane, enzymes of lysosomes

Smooth = functions in lipid synthesis (including steroids), carbohydrate synthesis and metabolism, drug detoxification, and calcium storage in muscle cells

0.5 micrometers

smooth endoplasmic reticulum

vesicles

ribosomes

rough endoplasmic reticulum

0.5 micrometers

Figure 3.9 The Golgi ApparatusFigure 3.9 The Golgi Apparatus

Functions of the Golgi Functions of the Golgi ApparatusApparatus

MitochondrionMitochondrion

MitochondriaMitochondria

LysosomesLysosomesMembrane bound vessels that pinch off from Golgi apparatusContain digestive enzymesPerform clean up and duties

LysosomesLysosomes

LysosomeLysosome

From Krogh, “Biology: A Guide to the Natural World, 2nd edition

nucleus

CytoskeletonCytoskeleton

Major components:

1. Microtubules (composed of tubulin subunits)

2. Microfilaments (mostly actin and myosin)

3. Intermediate filaments

Functions: support & movement of cellular structures & materials

CytoskeletonCytoskeleton

2 centrioles direct formation of mitotic spindle

In 9+0 array

CiliaCilia Cell surface Cell surface

projectionsprojections Capable of Capable of movementmovement Moves materials Moves materials over over

the cell surfacethe cell surface Sensory capabilitiesSensory capabilities

Centrioles and CiliaCentrioles and Cilia

MicrovilliMicrovilli

Extension of plasma Extension of plasma membranemembrane

Increase the cell Increase the cell surfacesurface

Normally manyNormally many on on each celleach cell

Form a brush Form a brush border on the apical border on the apical surface of the cellsurface of the cell

Do not moveDo not move