Ch 4: Eukaryotic Cells and Microorganisms

NOT FINISH - Note to self add images from slides

Which eukaryotic structure:

• Different from bacterial flagella

• About ten times thicker & structurally more complex

• Covered by an extension of the cell membrane

• Long, sheathed cylinder containing regularly spaced microtubules

Eukaryotic flagella

Which eukaryotic structure:

• Similar to flagella in structure, but are smaller and more numerous

• Found only in a single group of protozoa and certain animal cells

Eukaryotic cilia

The _ is the outermost layer that comes into direct contact with the environment, and is composed of polysaccharides.

glycocalyx

The __ can appears as:

• A network of fibers

• A slime layer

• A capsule

glycocalyx

The __ contributes to protection, adherence, and signal reception.

glycocalyx

Protozoa and helminths do not have __.

cell walls.

Cell walls of __:

• Rigid and provide structural support and shape

• Different in chemical composition from bacterial and archaeal cell walls

fungi

The __ is typical bilayer of phospholipids in which protein molecules are embedded.

cell membrane

What contain sterols of various kinds:

• Relative rigidity give stability to the membrane

• Important in cells that do not have a cell wall

Cell Membrane

What is found in the nucleoplasm, a site for ribosomal RNA synthesis, and a collection area for ribosomal subunits?

Nucleolus

What is made of linear DNA and histone proteins, and is genetic material of the cell?

Chromatin

Which type of Endoplasmic Reticulum:

• Allows transport materials from the nucleus to the cytoplasm and to the cell’s exterior

• Ribosomes attached to its membrane surface hence its ‘rough’ appearance

Rough endoplasmic reticulum (RER)

Which type of Endoplasmic Reticulum:

• Closed tubular network without ribosomes

• Functions in nutrient processing and in synthesis and storage of nonprotein macromolecules such as lipids.

Smooth endoplasmic reticulum (SER)

What is the site in cell where proteins are modified and sent to their final destinations?

Golgi Apparatus

The __ consists of several flattened disc-shaped sacs call cisternae.

golgi apparatus

Transitional vesicles from the __ are picked up at the face of the Golgi apparatus.

endoplasmic reticulum

Proteins are __ with the cisternae by the addition of polysaccharides and lipids.

modified

Condensing vesicles pinch off of the __ and are then conveyed to __ or transported outside the cell.

golgi apparatus, lysosomes

Which type of vesicle:

• Bud off the Golgi apparatus as a vesicle

• Participate in the removal of cell debris in damaged tissue

Lysosomes

What contain a variety of enzymes involved in the intracellular digestion of food particles and protection against invading microorganisms?

Lysosomes

Which type of vesicle:

• Membrane-bound sacs containing fluids or solid particles to be digested, excreted, or stored

• Found in phagocytic cells in response to food and other substances that have been engulfed

Vacuoles

The __ generate energy for the cell, and is composed of a smooth, continuous outer membrane with an inner folded membrane.

Mitochondria

Folds on the inner membrane are called __, and hold the enzymes & electron carriers of __.

cristae, aerobic respiration.

The __ are unique organelles:

• Divide independently of the cell

• Contain circular strands of DNA

• Have bacteria-sized 70S ribosomes

Mitochondria

What is found in algae and plant cells, and capable of converting solar energy into chemical energy through photosynthesis?

Chloroplasts

Which cell organelle:

• Produce oxygen gas as a by-product of photosynthesis

• Resemble mitochondria but are larger, contain special pigments, and are more varied in shape

Chloroplasts

Which theory:

• Evidence that mitochondria and chloroplasts came about from bacteria

• Early eukaryotes ingested that bacteria and together they formed a symbiotic relationship

Endosymbiotic Theory

Which cell organelle:

• Scattered freely in the cytoplasm and cytoskeleton

• Attached to the rough endoplasmic reticulum

• Appear inside mitochondria and chloroplasts

Ribosomes

Which organelle has these functions:

• Anchoring organelles

• Moving RNA and vesicles

• Permitting shape changes and movement

Cytoskeleton

Three main types of __ elements:

• Actin filaments: long, thin protein strands

• Intermediate filaments: ropelike structures

• Microtubules: long, hollow tubes

Cytoskeleton

Which of the following characteristics is evidence that mitochondria evolved from bacterial cells?

All of the choices are correct

Which of the following organelles is responsible for protein modification and distribution in the cell?

Golgi apparatus

Which fungal cell:

• Round to oval shape

• Asexual reproduction, budding

Yeasts

Which fungal cell:

• Long, threadlike cells found in the bodies of filamentous fungi

Hyphae

Pseudohyphae are chains of __ cells.

yeast

Harmless __ can cause opportunistic infections in AIDS patients.

spores

The fungal __ give off substances that cause allergies.

cell walls

Toxins produced by poisonous __ can induce neurological disturbances and death.

mushrooms

__ synthesizes a poison called aflatoxin, potentially lethal to animals who eat contaminated grain.

Aspergillus flavus

Benefits of __:

• Play an essential role in decomposing organic matter

• Form stable associations with plant roots and increase their ability to absorb water and nutrients

• Fungi have been engineered to produce large quantities of antibiotics, alcohol, organic acids, and vitamins

Fungi

Which fungal nutrition:

• Acquire nutrients from a wide variety of organic substrates (all fungi are heterotrophs) … some are others.

Heterotrophic

Which fungal nutrition:

• Obtain nutrients from the remnants of dead plants and animals in soil or aquatic habitats.

Saprobic

Which fungal nutrition:

• Grow on the bodies of living animals or plants, although very few require a living host.

Parasitic

Cells of most microscopic __ grow in loose associations or colonies.

fungi

Colonies of filamentous __ are noted for the striking cottony, hairy, or velvety texture.

fungi

__ - the woven, intertwining mass of hyphae that makes up the body or colony of a mold.

Mycelium

__ - the nature of the septa varies from solid partitions with no communication between the compartments to partial walls with small pores that allow the flow of organelles and nutrients between adjacent compartments:

• Nonseptate hyphae consist of one, long, continuous cell

Septa

__ - are responsible for the visible mass of growth that appears on a substrate.

Vegetative hyphae

Reproductive, or fertile, hyphae produce __.

spores.

__ - can be formed by asexual or sexual reproduction.

Spores

__ - formed by successive cleavages within a saclike head called a sporangium, which is to a stalk, the sporangiophore.

Sporangiospores

__ - free spores not enclosed by a spore-bearing sac.

Conidiospores or conidia

Environmental requirements of __ are:

• pH of 5 (too acidic for most bacteria)

• Molds are aerobic; yeasts are facultative anaerobes

• More resistant to osmotic pressure than bacteria; will grow in relatively high sugar or salt concentrations

• Can grow in low moisture content

• Can metabolize complex carbohydrates, most of which cannot be used bacteria

fungi

__ - deep within tissues/organs usually breathed in initially (valley fever/coccidiomycosis)

Systemic Mycoses

__ - in skin (gardeners/farmers enter through a wound)

Subcutaneous Mycoses

__ - only in epidermis hair or nails these fungi called dermatophytes.

Cutaneous Mycoses

__ - pneumonia found in AIDS pts

Pneumocystis

__ - yeast infection caused by candida albicans resulting in thrush or vulvovaginal candidiasis. Usually seen in newborns, AIDS pts and individuals treated with broad spectrum antibiotics.

Candidiasis

A small amount of candida albicans is nearly always present in the female within the __, but is kept in check by pH produced by normal __.

vagina, bacteria.

From which sources can fungi derive nutrients?

All of the choices are correct.

What are single cells containing all eukaryotic organelles except chloroplasts, and most are harmless, free-living inhabitants of water and soil?

Protozoa

Which part of protozoa cytoplasm:

• Clear outer layer involved in locomotion, feeding, and protection

Ectoplasm

Which part of protozoa cytoplasm:

• Granular inner region housing the nucleus, mitochondria, and food & contractile vacuoles

Endoplasm

Cell shape of protozoa can remain __ (as in most ciliates), or change __ (as in amoebas).

constant, constantly

Main limiting factor for protozoa growth is availability of __.

moisture

Protozoa can survive in extremes of __ and __.

temperature, pH.

Many protozoa can convert to a resistant, dormant stage called a __.

cyst.

__ is motile feeding stage requiring ample food and moisture to stay active.

Trophozoite

What are these characteristics of:

• Dormant, resting stage when conditions in the environment become unfavorable (with protozoa)

• Resistant to heat, drying, and chemicals

• Can be dispersed by air currents

• Important factor in spread of disease

Cyst

__ - a common STD, does not form cysts and must be transmitted by intimate contact.

Trichomonas vaginalis

Entamoeba histolytica (amoebic dysentery) and Giardia lamblia form __ and are readily transmitted in __ water and food.

cysts, contaminated

The active, feeding and motile stage of the protozoan life cycle is the __ stage.

trophozoite

Which type of helminth:

• Have a thin, often segmented body plan

• Divided into cestodes (tapeworms) and trematodes (flukes)

Flatworms

Which type of helminth:

• Have an elongated, cylindrical, unsegmented body

• Also called nematodes

Roundworms

Which type of helminth:

• Pinworm or seatworm

• Common infestation of the large intestine

• Range from 2 - 12cm long with a tapered, curved cylindrical shape

Enterobius vermicularis