BIOL 3340 BIOL 3340 Chapter 3Chapter 3

Chapter 4 Chapter 4

Microbial Cell Structure

Eucaryotes

Eucaryotic Cell StructureEucaryotic Cell Structure

•membrane-delimited nuclei

•membrane-bound organelles that perform specific functions

•more structurally complex than procaryotic cell

•generally larger than procaryotic cell

Size, Shape, and Arrangement of Eucaryotes

Yeast cell and Protozoan cellYeast cell and Protozoan cell

Functions of the cell Functions of the cell organellesorganelles

Eucaryotic MembranesEucaryotic Membranes

Includes: animal & plant cells, fungi & protists (protozoa & algae).).

Have a true nucleus with DNAHave a true nucleus with DNA DNA is enclosed in a membrane-

bound nucleus membrane-enclosed cell

organelles

…Eucaryotic Membranes

the fluid mosaic model is based on eucaryotic membranes

They are enriched with lipids and proteins

They participate in a variety of cell processes such as cell movement and transduction

Cell Structureof Eucaryotes- animal cell

Cell Structureof Eucaryotes- Plant Cell Plant Cell

…Eucaryotic membrane

Cytoplasm

Many organelles of eucaryotic cells lie in the cytoplasmic matrix

The cytoplasmic matrix -vast network of interconnected filaments.

Filaments that form the cytoskeleton: microfilaments, microtubules, and intermediate filaments.

plays role in both cell shape and cell movement

..Cytoplasmic Matrix

Viscous aqueous suspension of proteins, nucleic acid, dissolved organic compounds, mineral salts

Network of protein fibers similar to the eukaryotic cytoskeleton.

Cytoplasmic Inclusion Bodies: granules of organic or inorganic material that are stockpiled by the cell for future use.

some are enclosed by a single-layered membrane

Microfilaments

minute protein filaments, 4 to 7 nm in diameter

scattered within cytoplasmic matrix or organized into networks and parallel arrays

composed of actin proteininvolved in cell motion and

shape changes

Microtubules

shaped like thin cylinders ~ 25 nm in diameter

composed of - and -tubulinhelp maintain cell shapeinvolved with microfilaments in

cell movements participate in intracellular

transport processes

…The Endoplasmic Reticulum

irregular network of branching and fusing membranous tubules and flattened sacs (cisternae – s., cisterna).

rough ER ribosomes attachedsynthesis of secreted proteins by ER-

associated ribosomes smooth ER

devoid of ribosomessynthesis of lipids by ER-associated

enzymes

The Endoplasmic Reticulum

…The Endoplasmic Reticulum The ribosomes -sites of synthesis of some

proteins that it transports

transports proteins, lipids, and other materials within cell.

Ribosomes in the eukaryotic cytoplasm are larger than prokaryotic ribosomes

Ribosomes are also found within mitochondria and chloroplasts; the ribosomes of these organelles are very similar in structure & size to prokaryotic ribosomes

Mitochondria

site where ATP is generated by electron transport and oxidative phosphorylation

..Mitochondria

Chloroplasts

site of photosynthetic reactions

Nucleus

Nucleus:membrane-bound structure that

houses genetic material of eucaryotic cell

Chromatindense fibrous material within nucleuscontains DNAcondenses to form chromosomes

during cell division

…Nucleus

Nuclear envelope:double membrane structure that

delimits nucleuspenetrated by nuclear pores

pores allow materials to be transported into or out of nucleus

Nucleolus:important in ribosome synthesis

Other cell inclusions

Golgi bodies- involved in modification, packaging, and secretion of materials

Lysosomes- membrane-bound vesicles found in most eucaryotes

involved in intracellular digestion Vacuoles-transport system

Reproduction

Eucaryotes:asexual reproduction

transverse fissionbuddingspore production

sexual reproductioninvolves union of compatible nuclei

followed by formation of sexual spores

BibliographyBibliography

http://en.wikipedia.org/wiki/Scientific_methodhttp://en.wikipedia.org/wiki/Scientific_method https://files.kennesaw.edu/faculty/jhendrix/https://files.kennesaw.edu/faculty/jhendrix/

bio3340/home.htmlbio3340/home.html Lecture PowerPoints Prescott’s Principles of Lecture PowerPoints Prescott’s Principles of

Microbiology-Mc Graw Hill Co.Microbiology-Mc Graw Hill Co.http://images.search.yahoo.com/search/http://images.search.yahoo.com/search/

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