Micro Lecture Exam 2

Define inclusions (or "inclusion bodies") and give two examples.

Found within the cytosol of bacteria; deposits of lipids, starch, or compounds containing nitrogen, phosphate, or sulfur. Ex: glycogen granules in the liver and muscle cells and lipid droplets in fat cells.

Gram-negative bacteria are divided into two major groups, called _______________ and _________________.

Gram-negative bacteria are divided into two major groups, called Proteobacteria and Nonproteobacteria

Describe the clinical implications of the structure of the Gram-negative cell wall.

Gram-negative cells contain Lipid A. Dead Gram-negative cells release lipid A when the outer membrane disintegrates. Lipid A may trigger fever, vasodilation, inflammation, shock, and blood clotting in humans.

List the four kingdoms of eukaryotes, as discussed in class lecture

Kingdom Protista Kingdom Fungi Kingdom Plantae Kingdom Animalia

Discuss the structure and function of bacterial flagella.

Located outside the cell wall of the bacteria and are made of chains of the protein flagellin. They are attached to a protein hook and anchored to the wall and membrane by the nasal body. Its function is to provide a "swimming" movement for most motile prokaryotes. Not all bacteria have them, but are common in bacteria.

Discuss the function of the chloroplast

Photosynthesis (e.g., algae, plants) for nutrients for the cell

List and discuss the taxonomy and general biology of the following non-pathogenic taxa in the Phylum Proteobacteria.

Phylum of Gram-negative bacteria

Discuss the function of the Endoplasmic reticulum

RER: protein synthesis, SER: lipid synthesis

Describe active processes by which materials cross a cytoplasmic membrane.

Requires cells to expend energy in the form of ATP to move materials across the cytoplasmic membrane against their electrochemical gradient; includes active transport (uniport, symports, & antiports), and group translocation

What makes up the mosaic part of the fluid mosaic model?

The proteins of the phospholipid bilayer.

Discuss the function of the Mitochondria

Synthesis of ATP (powerhouse of the cell)

Discuss the function of the Vesicles (vacuoles)

Transports material inside the cell

Name the five major taxonomic classes within the incredibly large and diverse formal Phylum Proteobacteria.

1. Alphaproteobacteria 2. Betaproteobacteria 3. Gammaproteobacteria 4. Deltaproteobacteria 5. Epsilonproteobacteria

Which of the following describes a difference between bacteria and archaea? A. Bacteria have cell walls composed of peptidoglycan, whereas archaea do not. B. Bacteria lack a nucleus, whereas archaea do not.

A. Bacteria have cell walls composed of peptidoglycan, whereas archaea do not.

Name four major types of eukaryotes.

A. Fungi B. Protozoa (Protists) C. Algae (Protists) D. Multicellular animal parasites

Describe the cell walls of Gram-positive bacteria in terms of structure and Gram staining.

Bacteria have a thick peptidoglycan cell wall and is composed of teichoic acids (polysaccharides). With the stain it usually will appear blue/purple in color.

Describe the cell walls of Gram-negative bacteria in terms of structure and Gram staining.

Bacteria have a thin peptidoglycan cell wall, then an outer membrane(LP's), and a periplasmic space (3 layer wall). They usually appear pink/ red with Gram staining.

_____________ respond to antibiotics _____________ do not.

Bacteria respond to antibiotics Archea do not.

Describe the major biological features of Kingdom Plantae.

Comprised of plants. Most of the plants are Eukaryotic and chlorophyll containing organisms. Cell walls of plant cells are comprised of cellulose. They have an ability to grow by cell division.

Discuss the function of the peroxisomes

Contains catalase, breaks down hydrogen peroxide

Discuss the function of the nucleus

Contains the DNA of the cell

What is the structures and functions of fimbriae.

Hair-like appendages that are made up of proteins that allow for attachment like mucous membranes. Short in length, they allow the bacteria to more adhere rather than movement.

Describe the major biological features of Kingdom Protista.

Simple eukaryotic organisms. Most of the organisms are unicellular, some are colonial and some are multicellular like algae. Most live in water, some in moist soil or even in humans and plants. Have a cytosome (cellular mouth), vacuoles (digestion) and anal pore

Describe common shapes of bacterial cells.

The three basic shapes: bacillus (rod-shaped), coccus (spherical), and spiral.

Discuss the primary features of Fungi.

Unicellular like yeasts

Describe the formation and function of endospores.

1. DNA is replicated. 2. Cytoplasmic membrane invaginates to form forespore. 3. Cytoplasmic membrane grows and engulfs forespore within a second membrane. Vegetative cell's DNA disintegrates. 4. A cortex of peptidoglycan is deposited between the membranes; meanwhile, dipicolinic acid and calcium ions accumulate within the center of the endospore. 5. Spore coat forms around endospore. 6. Endospore matures; completion of spore coat. Increase in resistance to heat and chemicals by unknown processes. 7. Endospore is released from original cell. The primary function of most of these is to ensure the survival of a bacterium through periods of environmental stress.

What is an arthropod?

A small animal invertebrate that has an external skeleton (chitin), a segmented body, and jointed appendages. It's kingdom is animalia, phylum arthropoda, with its classes being insecta (mosquito, flies) and arachnida (spider, ticks, mites)

List at least five characteristics of viruses

Acellular (not composed of cells) Are not considered living organisms Composed of genetic material, which is either DNA or RNA, surrounded by proteins Protein coat may be enclosed in a lipid envelope Viruses reproduce only inside the cells of a living host organism (must infect cells to reproduce and grow)

Discuss the primary features of Protozoa (protists).

All are unicellular but some can form multicellular aggregations. Many can move around with appendages (pseudopods, flagella, cilia), and may cause disease.

Describe the structure and function of ribosomes.

An organelle that is the site of protein synthesis. Composed of rRNA and protein. A circular nonmembranous structure that is in cytoplasm or bound to the ER.

Anopheles mosquito serves as vector for ________________the apicomplexan protozoan that causes malaria in humans.

Anopheles mosquito serves as vector for plasmodium the apicomplexan protozoan that causes malaria in humans.

What is a vector?

Any arthropod that may transmit disease. They transmit infectious pathogens directly and indirectly from an infected animal to human, or from human to human via bite, penetration, and gastrointestinal tract.

What is a hydrothermal vent community?

Archaea are primary producers in the communities, base of the food chain.

What is the structures and functions of flagella.

Are also made of proteins that are attached via protein hook and provide a swimming movement for the cell.

List and discuss the taxonomy and general biology of the following non-pathogenic taxa in the Class Alphaproteobacteria.

Are capable of growing/ living at very low levels of nutrients. Examples of this environment are deep oceanic sediments, glacial ice, or deep undersurface soil

What is the structures and functions of pili.

Are longer than fimbriae and there are only a few per cell. They are considered a special type of fimbriae and helps transfer DNA from one cell to another (conjunction).

Why are viruses not technically considered living organisms, by most biologists?

Are not made out of cells, they can't keep themselves in a stable state, they don't grow, and they can't make their own energy.

Bacteria in the Phylum Proteobacteria are ___________________________meaning that they obtain energy from chemicals, such as glucose. Non-proteobacteria organisms, which encompass many different phyla, include _____________________________, meaning that these species obtain energy from sunlight.

Bacteria in the Phylum Proteobacteria are Chemoheterotrophic meaning that they obtain energy from chemicals, such as glucose. Non-proteobacteria organisms, which encompass many different phyla, include Photosynthetic species, meaning that these species obtain energy from sunlight.

What are the major biological features shared by eukaryotes in the Kingdom Fungi?

Cell walls that contain the polysaccharide chitin, chemoheterotroph, all multicellular (except yeast), and reproduce and disperse via sexually produced and asexually produced spores.

Discuss the primary features of Algae (Protists).

Cellulose in the cell walls perform photosynthesis. Unicellular and multicellular, and their locomotion is based on flagella

Describe prokaryotic cell walls and cell membranes.

Chemically complex made of proteins/ polysaccharides or peptidoglycans. The membrane has no carbohydrates and lacks sterols but is similar in they are both a fluid mosaic of phospholipids and proteins.

In the Phylum Arthropoda (Kingdom Animalia), which two classes contain most arthropod vector species?

Class Insecta and Arachnida

Describe the major biological features of Kingdom Animalia.

Comprised of animals. Characteristics include eukaryotes, heterotrophic, and multicellular organisms

Describe the functions of a cytoplasmic membrane as they relate to permeability.

Controls the contents of the cell, allowing some substances to cross while preventing other from crossing; separates the contents of the cell from the outside environment. It's proteins act as pores, channels, or carriers to allow or facilitate the transport of substances the cell needs.

Explain the fluid mosaic model of cell membrane structure.

Describes the plasma membrane as a fluid combination of phospholipids, cholesterol, and proteins. Carbohydrates are attached to lipids (glycolipids) and to proteins (glycoproteins) extend from the outward-facing surface of the membrane.

Discuss the function of the lysosomes

Digestive enzymes (garbage disposal of cell)

Name two primary differences between the two prokaryotic domains: Domain Bacteria and Domain Archaea.

Domain Bacteria- Peptidogylcan; one RNA polymerase Domain Archaea- Pseudomurein (not a bilayer); three RNA polymerases; primary producers in hydrothermal vent communities

Provide the levels in the taxonomic hierarchy, as discussed in class lecture, and list these levels in the proper order. What is a mnemonic that you can use to remember the names and proper order of these levels?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. A mnemonic: Dear King Philip Came Over For Good Soup.

Many fungal species exhibit dimorphism. What does dimorphism mean? How is dimorphism related to infectious fungal diseases?

Fungi that have both a yeast phase and a mycelial phase (with septate hyphae) Instead of separating after division, they can form long structures called pseudophyphae; this change in growth can be related to temperature or other environmental factors.

Describe bacterial cytoplasm and its basic contents.

Gelatinous, elastic material inside a cell which is composed of cytosol, inclusions, ribosomes, and in many cells a cytoskeleton.

Describe the structural composition and function of glycocalyces.

Glycocalyces or glycocalyx is a gelatinous, sticky substance. It is located outside the cell wall. Its classified as a capsule or a slime layer. Extracellular polysaccharide allows cell to attach. It's function is attachment for the bacteria to surfaces or other cells.

Describe the major biological features of Kingdom Fungi.

Have cell walls that contain the polysaccharide chitin. Nutritional type: chemoheterotroph. All multicellular except yeasts. Reproduce and disperse via sexually produced and asexually produced spores

Discuss the function of the centrosome

Help separate chromosomes during mitosis

Critical thinking question Penicillin was called a "miracle drug" because it doesn't harm human cells. Why doesn't it?

Human cells do not make or need peptidoglycan. Penicillin targets bacteria cell walls preventing the final cross-linking step, or transpeptidation, in assembly of this macromolecule. The result is a very fragile cell wall that bursts, killing the bacterium. No harm comes to the human host because penicillin does not inhibit any biochemical process that goes on within us. Bacteria can also be selectively eradicated by targeting their metabolic pathways.

Distinguish between isotonic, hypertonic, and hypotonic solutions

Isotonic Solutions are two solutions that have the same concentration of solutes. Hypertonic solution has a higher concentration of solutes in one than the other. Hypotonic solutions the solution with a lower concentration of solutes.

Distinguish capsules from slime layers.

It's classified as a capsule if it is nearly organized, or a slime layer if unorganized and loose. Capsule prevents phagocytosis, is tightly attached to the bacteria, and is immunogenic used to make vaccines.

Describe eukaryotic cell walls and cell membranes.

Made up of polysaccharides that provides protection from the environment. They are chemically simple and composed of a phospholipid bilayer. The membranes contain steroid lipids (sterol) that strengthen and solidify the membrane when temperatures rise, and they help maintain fluidity when temperatures fall.

Discuss the function of the Golgi apparatus

Modification, transport of proteins

What are the names of common vectors of human disease?

Mosquitos, ticks, non- biting flies, and lice

Describe Endocytosis

Movement of large material into a cell and involves the cell membrane. Two forms: pinocytosis (smaller molecules) and phagocytosis (large particles).

Describe Exocytosis

Movement of large material out of a cell and involves the cell membrane.

Discuss the function of the microfilaments and microtubules

Movement of the organelles

Discuss the primary features of multicellular animal parasites.

Multicellular, are not strictly microorganisms but a part of their life is microscopic stages.

Describe passive processes by which materials cross a cytoplasmic membrane.

No cellular energy expenditure is required; includes simple diffusion, facilitated diffusion, and osmosis.

Non-pathogenic eukaryotes include _________, _____________, __________, and _________-__________ ____________. What kingdom do they belong to?

Non-pathogenic eukaryotes include algae, protozoa, fungi, and free-living worms. Kingdom Protista

Identify nonmembranous and membranous organelles.

Nonmembranous: Ribosomes, cilia, flagella, microfilaments, and centrioles Membranous: Nucleus, ER, Golgi bodies, lysosomes, mitochondria, vacuoles and plastids.

Discuss the function of the cilia and flagella

On the surface of the cell helps move the cell

Compare and contrast the cytoplasm of prokaryotes and eukaryotes.

Prokaryotes have no cytoskeleton and generally lack sterols and organelles. Eukaryotes have a cytoskeleton and also cytoplasmic streaming (movement of the fluid substance within a cell) which helps move nutrients, proteins, and organelles.

List at least four primary characteristics of bacteria.

Prokaryotes, Peptidoglycan cell walls, Binary fission, and for energy, bacteria use organic chemicals, inorganic chemicals, or photosynthesis

Compare and contrast prokaryotic and eukaryotic cells.

Prokaryotic cells lack a nucleus and their DNA is in the cytoplasm. This includes Bacteria and Archaea. They are much smaller than eukaryotic cells. Their cell wall is made of peptidoglycan. Eukaryotic cells are much larger and have a true nucleus membrane and nucleoli. They have membrane enclosed organelles and has a cell wall made phospholipids.

List at least four basic characteristics of archaea.

Prokaryotic, Unicellular, Live in extreme environments, Not pathogenic to humans, Cell wall contains pseudomurein (lacks peptidoglycan).

Compare and contrast the ribosomes of prokaryotes and eukaryotes.

Ribosomes in prokaryotes are much smaller and have membrane-bound organelles so the ribosomes float free in the cytosol. Eukaryotic ribosomes are larger. They consist of a 60S large subunit and a 40S small subunit, which come together to form an 80S particle having a mass of 4200 kd, compared with 2700 kd for the prokaryotic 70S ribosome.

How do axial filaments differ from typical bacterial flagella? Name two species that possess axial filaments.

The differ because most cells with them have an outer sheath since the whole bacteria is covered with them. This allows them to burrow and move. Treponema pallidum (syphilis), and Borrelia burgdorferi (Lyme disease).

Define Osmosis

The diffusion of water molecules across a semipermeable membrane in response to differing concentrations of solutes.

What makes up the fluid part of the fluid mosaic model?

The phospholipids of the phospholipid bilayer.

Critical Thinking Questions Why are cells SO small?

The short answer is that since they are so small, cells have a large surface area to volume ratio (SA/V ratio). Bacteria can't shrink more than they have already because there wouldn't be enough space left for DNA and necessary proteins. They can't get much bigger, because larger species have much greater energy demands in proportion to their increased girth.

Describe the phospholipid bilayer and explain its significance in reference to a cytoplasmic membrane.

The structure of a cytoplasmic membrane. The phosphate-containing heads of each phospholipid molecule are hydrophilic. The hydrocarbon tails of each phospholipid molecule are hydrophobic and huddle together with other tails in the interior of the membrane.

List evidence for the endosymbiotic theory.

The theory provides explanation for the presence of 70S ribosomes and circular DNA within mitochondria and chloroplasts, and it accounts for the presence of two membranes in each of the organelles. Mitochondria and chloroplasts have their own circular DNA, prokaryote fashion, and can still replicate, transcribe and translate some proteins. Their ribosomes are also fashioned as a prokaryotes would be.

Describe the structure and function of ribosomes and the cytoskeleton

These are the site for protein synthesis in cells; composed of protein and ribosomal RNA (rRNA). This is an internal scaffolding of protein fibers that play a role in forming a cell's basic shape, participates in division of one cell into two, participates in assembly processes, organizes interior contents, and, in at least some bacteria, participates in motility.

Describe common arrangements of bacterial cells (bacillus, coccus, and spiral).

They arrange as a spirochete (corkscrew), vibro (comma) which are curved rod shaped, chains of cocci (circular cells stuck together in a line), cluster of cocci, pair of cocci known as diplococci, and chains of bacilli.

What do prokaryotic and eukaryotic cells share in common?

They both share in that they have a plasma membrane, cytoplasm, DNA, and ribosomes.

Discuss the importance of members of the Domain Archaea to hydrothermal vent communities. In what way are hydrothermal vent communities termed an "exception"?

This is an exception to solar-based living systems and offers new hypotheses regarding the origin of life.

Describe the endosymbiotic theory of the origin of mitochondria, chloroplasts, and eukaryotic cells.

This theory suggests that eukaryotes formed when a larger aerobic (requiring oxygen) prokaryote surround and formed a union with a small prokaryote. The smaller prokaryote was not destroyed by the larger cell but instead became an internal parasite that remained surrounded by a vesicular membrane of the host. According to the theory, the internal, aerobic prokaryote eventually evolved into mitochondria, and it's cytoplasmic membrane became cristae. A similar scenario explains the origin of chloroplasts, evidence suggests that these chloroplast organelles were also once free-living bacteria. They originated from engulfed photosynthetic prokaryotes called Cyanobacteria.

Ticks serve as a vector for Borrelia bergdorferi , the spirochaete bacterium that causes _________ disease in humans.

Ticks serve as a vector for Borrelia bergdorferi , the spirochaete bacterium that causes Lyme Disease in humans.

List and discuss the taxonomy and general biology of the following non-pathogenic taxa in the Agrobacterium tumefasciens.

Used in agricultural biotechnology, plant pathogen causes tumors, and causes crown gall disease in plants; used to insert plasmid DNA into plant cells

Describe at least three of the biological features of Paramecium, a ciliated protozoan, that are analogous to the macroscopic structures of multicellular organisms.

Vacuoles= digestion Cytosome= Cell mouth Anal pore= anus

LPS is an endotoxin "layer". What does this mean?

When this layer disintegrates inside a host's good stream it releases it's Lipid A endotoxin.