Test 2 Study Guide Flashcards
Protists
A protist is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus.
Examples of protists include: Amoebas (including nucleariids and Foraminifera); choanaflagellates; ciliates; Diatoms; Dinoflagellates; Giardia; Plasmodium (which causes malaria); Oomycetes (including Phytophthora, the cause of the Great Famine of Ireland); and slime molds.
Protozoans
An informal term for a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris.
Some examples of protozoa are Amoeba, Paramecium, Euglena and Trypanosoma.
Algae
an informal term for a large and diverse group of photosynthetic eukaryotic organisms.
Fungi
Any of a group of spore-producing organisms feeding on organic matter, including molds, yeast, mushrooms, and toadstools.
Examples of fungi are yeasts, rusts, stinkhorns, puffballs, truffles, molds, mildews and mushrooms.
Helminths
Helminths are parasitic worms that can infect humans and other animals.
Ciliates
The ciliates are a group of protozoans characterized by the presence of hair-like organelles called cilia
Examples: Lacrymaria, Coleps, Stentor, Dileptus, Paramecium
Flagellates
A flagellate is a cell or organism with one or more whip-like appendages called flagella.
Flagellates may be solitary, colonial (Volvox), free-living (Euglena), or parasitic (the disease-causing Trypanosoma). Parasitic forms live in the intestine or bloodstream of the host. Many other flagellates (dinoflagellates) live as plankton in both salt and fresh water.
Sarcodina
These organisms have streaming cytoplasm and use temporary cytoplasmic extensions called pseudopodia in locomotion (called amoeboid movement) and feeding.
It includes the amoebas, heliozoan, rediozoa and foraminifera, which are characterized by their ability to move by cytoplasmic flow.
Apicomplexa
Apicomplexa is a large phylum of parasitic protists belonging to the Alveolata group, together with ciliates and dinoflagellates. Several of its members are causative agents of human diseases.
Examples: Plasmodium, Toxoplasma, Cryptosporidium
Cell wall composition of bacteria, algae, fungi, and plants
Bacteria - peptidoglycan
Fungi have thick inner layer of polysaccharide fibers composed of chitin or cellulose and a thin layer of mixed glycans
Algae – varies in chemical composition; substances commonly found include cellulose, pectin, mannans, silicon dioxide, and calcium carbonate
Plants - Cellulose
Cell envelope and cell exterior in bacteria
The cell envelope comprises the inner cell membrane and the cell wall of a bacterium.
The principal surface layers are capsules and loose slime, the cell wall of Gram-positive bacteria and the complex cell envelope of Gram-negative bacteria, plasma (cytoplasmic) membranes, and mesosomal membrane vesicles, which arise from invaginations of the plasma membrane.
Structure and function of eukaryotic organelles
Nucleus: The “brains” of the cell, the nucleus directs cell activities and contains genetic material called chromosomes made of DNA.
Mitochondria: Make energy out of food
Ribosomes: Make protein
Golgi Apparatus: Make, process and package proteins
Lysosome: Contains digestive enzymes to help break food down
Endoplasmic Reticulum: Called the “intracellular highway” because it is for transporting all sorts of items around the cell.
Vacuole: Used for storage, vacuoles usually contain water or food.
Chloroplasts: Use sunlight to create food by photosynthesis
Cell Wall: For support
Autotrophic vs. Heterotrophic
Autotrophs are known as producers because they are able to make their own food from raw materials and energy.
Heterotrophs are known as consumers because they consume producers or other consumers.
Types of Fungi
Macroscopic fungi (mushrooms, puffballs, gill fungi)
Microscopic fungi, with two morphologies
• Hyphae – long filamentous fungi or molds
• Yeast – round ovoid shape, asexual reproduction
Types of parasitic worms
Flatworms – flat, no definite body cavity; digestive tract a blind pouch; simple excretory and nervous systems
• Cestodes (tapeworms)
• Trematodes or flukes, are flattened, nonsegmented worms with sucking mouthparts
Roundworms (nematodes) – round, a complete digestive tract, a protective surface cuticle, spines and hooks on mouth; excretory and nervous systems poorly developed. Pinworms
Structure of viral particles and function
Covering
• Capsid
• Envelope (not found in all viruses)
Central core
• Nucleic acid molecule(s) (DNA or RNA)
• Matrix proteins Enzymes (not found in all viruses)
Viral shapes, nucleic acid and proteins
Helical – continuous helix of capsomers forming a cylindrical nucleocapsid
• plum poxvirus
Icosahedral –three-dimensional, symmetrical polygon, with 20 sides and 12 evenly spaced corners
• Rotavirus (naked)
• Herpes simple (enveloped)
Host cell viruses
CD4+T lymphocytes, monocytes, macrophages, and dendritic cells (DC) are the host cells for HIV (Human immune deficiency virus)
Respiratory tract epithelial cells are the host cells for the Influenza virus
Macrophages, dendritic cells, and fibroblasts are the host cells for the Ebola virus
Nerve cells and salivary gland epithelial cells serve as host cells for the Rabies virus
Naked vs. Enveloped virus
Some viruses have an external covering called an envelope; those lacking an envelope are naked
Environmental factors that affect physiology of microbes
Moisture. Oxygen. Carbon Dioxide. Temperature. pH. Light. Osmotic Effect. Mechanical and Sonic Stress.