Chapter 4 - Introduction to Eukaryotic Cells

1. What is dimorphic fungi?

-Cycle between hyphae and living as a yeast-like form -Many pathogenic fungi are dimorphic

1. What is the nucleolus?

-Dense area in the nucleus -Enriched with RNA -Site where ribosomal subunits begin their development

1. What is indicated by the term tinea?

-Dermatophytic infections are "tinea"

What is the function of a chloroplast?

-Function: §Harvest energy from sunlight using light-collecting pigments

1. Review the structure and function of mitochondria and state what features make them similar to bacteria.

-Functions: §Make ATP, amino acids, and vitamins §Regulate cell division §Carry out programmed cell death (apoptosis) §Play a role in cancer and aging -Structure: §Smooth outer membrane §Inner membrane of cristae §Matrix

1. What type of eukaryotic cells possess a cell wall?

-Fungi, plants, and certain protists have cell walls

1. Name the organelle that builds microtubules.

-Made of tubulin

1. What three components make up the cytoskeleton?

-Microtubules -Intermediate filaments -Microfilaments

What is the difference between a mold and yeast?

-Mold are multicellular -Yeasts are unicellular

What type of molecule is commonly (and uniquely) associated with eukaryotic cell plasma membranes?

-Phospholipid bilayer structure

1. Provide a basic description of a eukaryotic cell and state how eukaryotes differ from prokaryotes.

-Plants, animals, protists, and fungi -Larger in size and more complex than prokaryotic cells -Larger genomes with multiple linear chromosomes

1. What cells have 70S ribosomes? What cells have 80S ribosomes?

-Prokaryotic cells have "small" ribosomes called 70S ribosomes. -Eukaryotic cells in their cytoplasm have "large" ribosomes, called 80S ribosomes.

1. Describe the general structural and functional features of the Golgi apparatus.

-Series of cisternae (disc-like, flattened sacs) -Modifies cellular proteins, build lipids, sorts and distributes finished products -Vesicles bud off Golgi

1. What is a dermatophyte?

-True pathogens -Infect skin, hair, and nails Dermatophytic infections are "tinea

What is a fluke?

A flat parasitic worm

Give examples of human mycoses.

Candidiasis. Candidiasis (due to C albicans and other Candida spp.) is the most common opportunistic fungal infection.

Name and describe the five main classes of fungal spores.

Chytridiomycota, Zygomycota, Glomeromycota, Ascomycota, and Basidiomycota.

1. What type of eukaryotic cell component contains a nine-plus-two arrangement?

Microtubules

Do eukaryotic cell walls contain peptidoglycan?

No they lack peptidoglycan.

What eukaryotic cells contain chloroplasts? Which contain mitochondria?

Only photosynthetic cells have chloroplasts, but most eukaryotic cells, including plant cells have mitochondria.

Name the two main groups of parasitic helminths.

Roundworms and flatworms

Which stage of the apicomplexa life cycle is infectious?

Sporogony

Describe the endosymbiotic theory.

The endosymbiotic theory states that the first eukaryotic cells were formed from symbiosis among different prokaryotic cells. Mitochondria evolved from an engulfed nonphotosynthetic prokaryotes. Another type that carried out photosynthesis evolved into chloroplasts. Both types were engulfed by other cells.

What is the difference between septate hyphae and aseptate hyphae?

The key difference between septate and aseptate hyphae is that septate hyphae have septa or cross walls that divide hyphae into distinct cells while aseptate hyphae lack septa. ... In order to separate cells within the hypha

What is the function of a vesicle?

To store and transport molecules The Golgi apparatus modifies cellular proteins, builds lipids, and sorts and distributes a variety of products for the cell with vesicles that bud off the organelle.

What is a mycotoxin?

a toxin produced by a fungus

1. Describe the structure and function of cilia.

are structurally similar to flagella except they are much shorter and more numerous on a cell

1. Discuss the basic structural and functional features of the endoplasmic reticulum.

has essential roles in protein and lipid production

Describe the stages of the apicomplexa life cycle including merogony, gamogony, and sporogony.

merogony, asexual cell divisions produce multiple merozoites gamogony,meiosis produces gametes from merozoites sporogony, Repeated cell divisions of the zygote make sporozoites.

What is a nematode?

roundworm

What is a cestode?

tapeworm

organelles associated with eukaryotic cells.

the nucleus, mitochondria, golgi apparatus, ribosomes, endoplasmic reticulum, peroxisome and vacuole. The chloroplast is found in plant and some protist cells, and the flagellum is found in some eukaryotic cells.

1. Compare eukaryotic and prokaryotic flagella.

~Prokaryotic Flagella -Built from flagellin protein -No microtubules -Membrane not enclosed except for periplasmic flagella -Hook-and-filament structures anchored by rings -Propeller motion, rotary ~Eukaryotic Flagella -Built from tubulin protein -Microtubules yes, 9+2 arrangement -Membrane enclosed -Microtubules sprout from a centriole -Wavelike motion

List the four main groupings of protozoans and give examples of human pathogens for each group.

•Amoeboid protozoans -Use pseudopods for movement -Some are free living -Examples of pathogens: §Naegleria fowleri §Acanthamoeba §Entamoeba histolytica (most common amoeboid infection in humans) •Flagellated protozoans -≥1 flagella for motility -Examples of pathogens: §Trichomonas vaginalis §Trypanosoma spp. §Giardia lamblia •Ciliated protozoans -Use cilia for motility -Common in aquatic environments -Example of pathogen: §Balantidium coli is the only ciliated protozoan known to cause human disease •Apicomplexa -Largest phyla of protozoans -Move by gliding (no flagella, cilia, or pseudopodia) -Most are obligate intracellular parasites -Complex life cycles §Merogony §Gamogony §Sporogony

1. Name and describe the four kingdoms of eukaryotes.

•Animals -Multicellular organisms -No photosynthesis -Obtain organic carbon from nutrients -~7.5 million animal species -Include parasitic worms (helminths) and arthopods •Plants -Multicellular organisms ->290,000 different species -Contain chloroplasts -Carry out photosynthesis -Vegetation can serve as a vehicle for infectious pathogens •Fungi ->600,000 different species -Mold are multicellular -Yeasts are unicellular -Do not carry out photosynthesis -Absorb nutrients from their environment -Include pathogens and saprobes •Protists are a diverse group of eukaryotes -Unicellular, multicellular or multinucleated masses -Autotrophs or heterotrophs -Asexual and sexual reproduction -Cell wall or no cell wall -Algae, slime molds, and protozoans

1. Explain the structure and function of the cytoskeleton.

•Cytoskeleton is a dynamic and responsive intracellular network of protein fibers -Cytoskeleton functions: §Helps maintain shape §Facilitates movement §Protects against forces §Directs transport Coordinates cell division

Define mycosis and true pathogen.

•Diseases caused by fungi are called mycoses •Most mycoses occur in: -Immunocompromised individuals -People who experience a disruption of their normal microbiota (e.g., yeast infections caused by Candida) •Some fungi are true pathogens that infect typically healthy hosts -Examples: §Histoplasmosis §Coccidioidomycosis

1. Define endocytosis and exocytosis.

•Endocytosis imports things into the cell •Exocytosis -Vesicles deliver their contents to the plasma membrane

1. Is the nuclear envelop continuous with any other organelle?

•Endoplasmic reticulum is continuous with the nuclear envelope at certain spots

1. What is the name of sexual and asexual reproduction in eukaryotic cells?

•Eukaryotic cells can exhibit asexual (mitosis) and/or sexual (meiosis) reproduction

1. Discuss the basic structure of eukaryotic flagella.

•Eukaryotic flagella are made of tubulin and have a nine-plus-two arrangement (9 + 2) •Anchored to the cell by a basal body •Eukaryotic flagella have a wavelike, back-and-forth motion

1. Describe the structure of eukaryotic ribosomes and state where they are located.

•Eukaryotic ribosomes can be free or bound to the endoplasmic reticulum -Bound ribosomes produce proteins that are destined for secretion from the cell -Free ribosomes produce cytosolic proteins -Ribosomes can change from free to bound, based on the protein production demands of the cell

How are protozoan classified?

•Grouped based on their means of motility in mature form -Amoeboid, Flagellated, Ciliated, Spore forming

1. Briefly describe mitosis and meiosis.

•Mitosis -Generates two genetically identical offspring from one parent cell -Offspring cells maintain the same number of chromosomes as the parent cell •Meiosis -Involved in sexual reproduction -Consists of two cell division stages -One parent cell produces four gametes (daughter cells) -Crossing over allows for genetic recombination

1. Describe the eukaryotic glycocalyx and list some of its roles.

•Most eukaryotes have a sticky extracellular layer called a glycocalyx as their outermost layer. This serves roles in cell protection, adhesion, and assisting with cellular communication. -Contains a diverse collection of carbohydrates, glycoproteins, and glycolipids

1. Describe pinocytosis, phagocytosis, and receptor-mediated endocytosis.

•Pinocytosis ("cell drinking") -Endocytosis of dissolved substances in small vesicles •Phagocytosis ("cell eating") -Endocytosis of undissolved substances ~Receptor-mediated endocytosis is a process through which bulk amounts of specific molecules can be imported into a cell after binding to cell surface receptors.

1. Briefly describe protozoan.

•Protists are a diverse group of eukaryotes -Unicellular, multicellular or multinucleated masses -Autotrophs or heterotrophs -Asexual and sexual reproduction -Cell wall or no cell wall -Algae, slime molds, and protozoans

1. Outline the types of vesicles and vacuoles that exist in eukaryotic cells and state their general functions.

•are lipid bilayer sacs -Transport vesicles move substances around the cell -Secretory vesicles shuttle materials to the cell surface for discharge from the cell -Lysosomes contain hydrolytic enzymes that break down substances engulfed by the cell -Peroxisomes contain enzymes that break down fats and amino acids by oxidation

1. Describe the general structure and function of the nucleus.

•houses DNA -DNA is loosely organized as chromatin -DNA floats in the nucleoplasm

1. What is the difference between the rough ER and the smooth ER?

•rough ER -Millions of ribosomes on the outer surface -Proteins are directly inserted into the ER membrane or transported into the lumen -Modifies proteins (e.g., clips, folds) •smooth ER -Not associated with ribosomes -Involved in lipid production -Detoxifies