VMCB LONG QUIZ pt 2

Eukaryotes

• Greek eu means TRUE and karyon which means NUT or KERNEL

• Has several membrane-bound organelles present within the cell (has true nucleus)

• complex structures require longer time for cellular division (18-24 hrs)

• includes algae, fungi, protozoa, plants, animals

• its ribosome is larger (80s) compared to prokaryotes.

• cell wall is also present (plant and fungi only)

• capable of pinocytosis and phagocytosis (animal cell)

• Nucleus

• Nuclear membrane

• Nucleolus

• Centrioles

• Chloroplasts

• Cytoskeleton

• Endoplasmic Reticulum

• Golgi apparatus

• Lysosome

• Mitochondria

• Ribosomes

• Vacuoles

• Cytoplasm/Protoplasm/Cytosol

• Cell wall

• Plasma membrane

Parts of a Eukaryotic Cell

Nucleus

• spherical in shape, where the chrosomes (DNA) are located

• chromosomes is where genetic information is stored which is marked by the presence of DNA.

Nuclear membrane

• cell structure that surrounds the nucleus

Nucleolus

• found within the nucleus, it contains RNA which is needed for protein synthesis.

Centrioles

• cylindrical pairs of organelles located near the nucleus which are composed of 9 tubes and 3 tubules.

• they are involved in cellular division.

Chloroplasts

• cell structures normally found in plant cells, it contains green chlorophyl.

Cytoskeleton

• composed of microtubules, it supports the cell by providing shape and structure.

Endoplasmic reticulum

• serving as the cell’s transport system, it is classified into two types according to the presence and absence of ribosomes.

• Rough and Smooth ER.

Rough endoplasmic reticulum

• presence of ribosomes

Smooth endoplasmic reticulum

• absence of ribosomes

Golgi apparatus

• membrane located near the nucleus; it is composed of numerous layers that forms a protein-packaging sac.

Lysosome

• sac-like structures or organelles that are responsible for the removal and/or transport of undigested materials

• these are digestive plants for proteins, lipids, and carbohydrates.

Mitochondria

• 2nd largest organelle, it is a double-layered sac composed of inner folds known as cristae where energy producing chemical reaction takes place.

• it recycles and decomposes proteins, fats, and carbohydrates while forming urea.

Ribosomes

• composed of RNA

• these are miniature protein factories that comprise 25% of the cell mass, site of protein synthesis.

• classified according to their location.

• stationary and mobile ribosomes.

Stationary ribosomes

• these are embedded in the endoplasmic reticulum

Mobile ribosomes

• these are found directly in the cytoplasm.

Vacuoles

• these are membrane-bound sacs that function for storage, digestion, and waste removal

Cytoplasm/Protoplasm/Cytosol

• fluid matrix, semisolid in nature, found within the cell, but outside the nucleus, where all the organelles are suspended.

Cell wall

• complex, highly organized structure that defines the shape of the plant cell (fungi, algae, and even bacteria)

• it controls turgidity.

Cell/Cytoplasmic/Plasma Membrane

• it is the outer membrane of cells that controls cellular traffic

• contains proteins that are surrounded by a phospholipid layer.

Prokaryotes

• Greek pro means BEFORE and karyon means NUT or KERNEL

• these are organisms with primordial nucleus and have simpler morphology than eukaryotes

• best example is the bacteria and archaea.

• bounded by the plasma membrane but has no other separate membrane-bound organelles (no true nucleus)

• their cells are able to divide into two independent cells in as little as 15 minutes.

• possess a cell wall that is external to the cytoplasmic membrane which contains N-acetyl Muramic acid (NAM), component of the peptidoglycan

• possess ribosomes smaller (70s) than those eukaryotes

• unable to phagocytose (engulf particles)

• bacteria/bacterium

• fungi/fungus

• protozoa

• algae

Cellular Microorganisms

Bacteria/Bacterium

• also known as prokaryotes, they are microscopic unicellular or single celled organisms that are considered to be part of the normal flora of the body.

• reproduce by binary fission.

• most are between 0.5 and 5 micrometer in length

• abundant in soil, water, and air and are major inhabitants of our skin, mouth, and intestines.

• Escherichia colli

• Salmonella

• Staphylococcus

Give me examples of opportunistic bacteria (those that cause diseases when an animal’s resistance is lowered)

Bacillus

-are rodlike

Coccus

are spherical or ovoid

Spiral

-are corkscrew or curved

-example is the Leptospira

Fungi/Fungus

• eukaryotes

• may be unicellular (Penicillium notatum) or multicellular (mushrooms)

• divided into two groups: molds and yeasts

Molds

• these are macroscopic eukaryotic fungi having a cottony appearance and under a microscope appear filamentous (hyphae)

• they reproduce asexually

Yeasts

• these are oval, unicellular microorganisms that are larger than the bacteria

• colony closely resembles that of bacteria

• they reproduce asexually (budding)

Protozoa

• protos first zoon animals

• typically unicellular, animal-like microorganism (protist) that are eukaryotic in nature

• they are principal hunters and grazers of the microbial world, they obtain nutrients by ingesting organic matter and other microbes

• they are classified by means of their locomotion (pseudopods, flagella, cilia)

• can produce sexually or asexually

• examples are Amoeba, Coccidia, Paramecium, Euglena (photosynthetic)

Algae or Alga

• these are thpically eukaryotic microorganisms (protist) that carry out photosynthesis

• together with Cyanobacteria, they produce 75% of the plante’s oxygen

• abundant in fresh and salt water, they are also found in the soil and in plants

• the cell walls are composed of a carbohydrate called cellulose

• they reproduce either sexually or asexually.

1. Virus

2. Prions

Acellular Microorganisms

Virus

• are submicroscopic acellular infectious particles that are obligate intracellular in nature

• devoid of machinery for metabolism

• may have DNA or RNA but not both

• not susceptible to the use of antibiotics

• are much smaller than bacteria, and range in size from 20 to 300 nanometers in diameter

• they are surrounded by a protein coat called capsids that are produced by structures called capsomeres

• some are enveloped and non-enveloped.

Viroids

• they are noted for their absence of a protein coat (capsomeres)

• contains only short pieces of RNA (small, infectious RNA)

• cause disease in plants (Potato spindle-tuber viroid or PTSV)

Prions

• infectious particles (abnormally folded protein) which are smaller than viruses and is capable of inducing conformational changes in corresponding normal host cell protein.

• causes neurodegenerative diseases, resulting to death in human and animals.

• known to cause Mad cow disease (bovine spongiform encephalopathies) and Scrapie (found in sheep and goats, causes them to scrape off large clumps of their wool).

• Creutzfeldt-Jakob disease

• Kuru

• Fatal Familial Insomnia

• Tansmissible spongiform encephalopathies

• Gerstmann-Strassler-Scheinker syndrome (GSS)

Other diseases thar are caused by PRIONS

Taxonomy

• the science of naming, describing, and classifying (orderly arranging) living organisms

• Carolus von Linnaeus (1735)

Nomenclature

• branch of taxonomy concerned with the system or manner of naming living organisms in agreement with publishes rules.

• giving off of names of taxonomic groups

• Latinized and Italicized (binomial system)

1. Eubacteria

2. Eukarya

3. Archaea

3 domains of Microbes

Eubacteria

• true bacteria, not rue nucleus (prokaryotes), with peptidoglycan on its cell wall, many pathogens are derived from here.

Eukarya

• have a distinct nucleus and organelles, classified as protists (protozoa and algae) and fungi

Archaea

• odd bacteria (without peptidoglycan) that live in extreme environments, high salt, heat, not associated with any disease, they can be found in a variety of environments ranging from lakes and soil to the Dead Sea and the deepest parts of the ocean (ocean floor)

Eukarya

Based on the cell structure of the three domains of life, this is the only eucaryotic one, the other 2 are prokaryotic.

Eukarya

The only domain with a membrane defined nucleus.

True

True or False: all of the 3 domains of microbes have ester-linked membrane lipids.

Bacteria

Muramic acid in cell walls is present only in this domain, in the other 2 it is absent.

Eukarya

This domain is the only one that has 80s ribosomes, while the other two have 70s.

Bacteria

This domain has 4 subunits of RNA polymerase complexity

Archaea

This domain has 8-12 subunits of RNA polymerase complexity.

Eukarya

This domain have 12-14 subunits of RNA polymerase complexity

Bacteria

The only domain that is sensitive to erythromycin.

Bacteria

The only domain that is sensitive to chloramphenicol/streptomycin