Microbiology

Microbiology Study Guide

deoxyribonucleic acid (DNA) is not delimited by the nuclear membrane. The DNA, in fact, has been dispersed to some magnitude throughout the cell. Cyanobacteria are omnipresent and are generally present in all kind of habitats. Chlorophyll a, P-carotene, Antheraxanthin, Aphanicin, Aphanizophyll, Flavacin, Lutein, Myxoxanthophyll, Oscilloxanthin, Zeaxanthin, Allophycocyanin, Phycocyanin, and Phycoerythrin are the major pigments found in these microorganisms. The storage products in cyanobacteria are cyanophycean starch and protein and they do not have flagella. They may be unicellular, colonial, and filamentous. Eukaryotic Cells: Protozoa, Algae, and Fungi (Yeasts and Molds) Cell Structure Eukaryotic cells are generally larger and more complex than prokaryotic cells. They also contain a variety of cellular bodies called organelles . The organelles function in the activities of the cell and are compartments for localizing metabolic function. Microscopic protozoa, unicellular algae, and fungi have eukaryotic cells. Plasma membrane is similar to the cell membranes of prokaryotic cells but is less versatile and contains a greater variety of lipids. The internal structure includes: • Cytoplasm: Semi-fluid substance consisting mainly of water • Cell nucleus: Contains DNA, some RNA, and some proteins • Mitochondria: Powerhouses of eukaryotic cells • Chloroplasts: Carry out photosynthesis • Ribosomes: Provide sites for protein synthesis • Endoplasmic reticulum: Forms the vesicles that transport lipids and proteins to the Golgi apparatus • Lysosomes: Contain digestive enzymes that digest the substances in vacuoles • Peroxisomes: Oxidize amino acids in animal cells and fats in plant cells • Vacuoles: Stores materials to be used for energy • Cytoskeleton: Supports and gives rigidity and shape to the cell The external structure includes: • Flagella: Helps cells to move • Cilia: Allows organisms to move rapidly • Pseudopodia: Helps cells move and ingests nutrients

©2018

Achieve

Page 17

of 132