Module 04: Cell Structure and Taxonomy Flashcards
This is the fundamental unit of any living organism because it exhibits the basic characteristics of life.
Cells
What are the two (2) categories of cells?
(1) Prokaryotic
(2) Eukaryotic
What are some microbes that are heeded to be prokaryotes?
Bacteria and Archaea Cyanobacteria
What are some microbes that are heeded to be eukaryotes?
Algae, Protozoa and Fungi
What are some microbes not composed of cells?
Virus Prions and Viroid
What is a true nucleus?
It consists of
(1) Nucleoplasm
(2) Chromosomes
(3) Nuclear membrane
What is the difference between eukaryotic and prokaryotic cells in terms of nucleus?
Eukaryotic cells contain a “true” nucleus, whereas prokaryotic cells do not.
What is the difference between eukaryotic and prokaryotic cells in terms of organelles?
Eukaryotic cells possess a complex system of membranes and membrane-bound organelles, whereas prokaryotic cells do not.
These have have selective permeability, allowing only certain substances to pass through them.
Cell Membrane (found in both eukaryotic and prokaryotic cells)
This is the command center of the cell.
Nucleus
What are the components of the nucleus?
(1) Nucleoplasm
(2) Chromosomes
(3) Nuclear membrane
Where are chromosomes embedded?
Nucleoplasm
This consist of linear DNA molecules and proteins.
Chromosomes
These are located in the chromosomes. Each of this contains the information to produce one or more gene products (usually proteins).
Genes
An organism’s complete collection of genes is referred to as its ___________.
Genotype or genome.
Although most genes code for proteins, some code for two types of ribonucleic acid (RNA) namely:
(1) Ribosomal ribonucleic acid (rRNA)
(2) Transfer ribonucleic acid (tRNA)
What are the characteristics of a particular species of an organism?
(1) Number and composition of chromosomes
(2) Number of genes on each chromosomes
Humans diploid cells have how many chromosomes?
46 chromosomes or 23 pairs
How many genes does one genome approximately have?
20,000 to 25,000 genes
This is a semifluid, gelatinous, nutrient matrix that contains storage granules and a variety of organelles.
Cytoplasm
Which reactions occur in the cytoplasm?
Metabolic reactions
This is a a highly convoluted system of membranes arranged to form a transport network in the cytoplasm
Endoplasmic Reticulum
What is the difference between the rough ER and smooth ER?
Rough ER has ribosomes attached to it, whereas smooth ER does not
This is known as the site for protein synthesis.
Ribosomes
What do ribosomes contain ?
(1) Ribonucleic acid (RNA)
(2) Proteins
This connects and communicates with the endoplasmic reticulum. This completes the transformation of newly synthesized proteins and packages them for storage or export
Golgi complex or Golgi Apparatus (Golgi Body)
These contain lysozyme and other
digestive enzymes
Lysosomes
Where do lysosomes originate?
Golgi complex or Golgi Apparatus (Golgi Body)
These are membrane-bound vesicles where H2O2 (hydrogen peroxide) is generated and broken down
Peroxisomes
These are known as power plants powerhouses or energy factories where a number of this vary depending on the activities of the cell.
Mitochondria
ATP molecules are produced within mitochondria by _____________.
Cellular Respiration
These are membrane-bound structures containing photosynthetic pigments
Plastids
Plastids are a site of?
Photosynthesis
These are examples of plastids that contain chlorophyll.
Chloroplasts
This is a system of fibers in the cytoplasm.
Cytoskeleton
What are three (3) types of fibers in the cytoskeleton?
(1) Microtubules
(2) Microfilaments
(3) Intermediate filaments
(Microtubules and microfilaments are essential for a variety of activities)
These are external structure to provide shape, protection, and rigidity.
Cell Wall (Some eukaryotic cells
contain cell walls)
These are found in the cell wall of fungi.
Chitin
These are found in the cell walls of algae and plants.
Cellulose
Cell walls are present in?
(1) Plants
(2) Algae
(3) Fungi
(4) Most Bacteria
Cell walls are absent in?
(1) Animals
(2) Protozoa
(3) Mycoplasma species
Flagella and cilia contain?
Microtubules
Some eukaryotic cells possess long, thin, whiplike organelles of locomotion called __________.
Flagella
What are some examples of eukaryotic organisms that have flagella?
(1) Spermatozoa
(2) Protozoa
Flagellated cells may contain how many flagella?
One or more
These are shorter, thinner, and more numerous than flagella, and described as being “hair-like.
Cilia
What are some examples of eukaryotic organisms that have cilia?
(1) Some species of protozoa
(2) Ciliated epithelial cells in our respiratory tract
Cross sections of cilia showing the _________________.
9 + 2 arrangement of microtubules.
How are prokaryotes and eukaryotes compared in size?
Prokaryotic cells are about 10 times smaller than eukaryotic cells. Prokaryotic cells are simple compared to eukaryotic cells.
Prokaryotic cells reproduce through?
Binary fission
What is the difference of the cytoplasm of prokaryotic from eukaryotic cells?
Unlike eukaryotic cells, the cytoplasm of prokaryotic cells is not filled with internal membranes.
The cytoplasm of prokaryotic cells is surrounded by a cell membrane, a cell wall (usually), and sometimes a
capsule or slime layer
In prokaryotic cells, this is a selectively permeable barrier. Many enzymes are attached to this where metabolic reactions take place
Cell membrane
In prokaryotic cells, this usually consists of a single, long, supercoiled, circular DNA molecule and serves as the control center of the cell
Chromosomes
In prokaryotic cells, these are small, circular molecules of DNA that are not part of the chromosome (extrachromosomal)
Plasmids
In prokaryotic cells, this is a semiliquid that consists of water, enzymes, waste products, nutrients, proteins, carbohydrates, and lipids materials required for metabolic functions
Cytoplasm
These are cytoplasmic particles that occur in clusters
Ribosomes
What is the function of the ribosomes?
Protein synthesis
A rigid exterior that defines the shape of bacterial cells, chemically complex
Bacterial cell wall
What is the primary constituent of bacterial cell wall?
Peptidoglycan (found only in bacteria)
This bacteria has a thick layer of peptidoglycan.
Gram positive bacteria
This bacteria has a thin layer of peptidoglycan.
Gram negative bacteria
These do not have cell walls; they are pleomorphic.
Mycoplasma species
What are the three (3) components of peptidoglycan?
(1) N-acetyl glucosamine
(2) N-acetyl muramic acid
(3) Cross linked peptide
This is a a slimy, gelatinous material produced by the cell membrane and secreted outside the cell wall.
Glycocalyx (slimy layers and capsule)
What are the two (2) types of glycocalyx?
(1) Slimy layer
(2) Capsule
This glycocalyx is loosely connected to the cell wall.
Slimy layer
This glycocalyx is highly organized and firmly connected to the cell wall.
Capsule
These produce a slime layer.
Pseudomonas
These possess a capsule, which serves an antiphagocytic function.
(1) Klebsiella pneumoniae,
(2) Neisseria meningitidis, and
(3) Streptococcus pneumoniae
These are bacteria that possess flagella.
Motile bacteria
These are whiplike appendages composed of threads of protein called flagellin.
Flagella
The flagella are whiplike appendages composed of threads of protein called ___________.
Flagellin
This species have flagella over entire surface
Peritrichous bacteria
This species have tuft of flagella at one end
Lophotrichous bacteria
This species have one or more flagella at both ends
Amphitrichous bacteria
This species have single polar flagellum
Monotrichous bacteria
These are hair like structures, most often observed on Gram-negative bacteria.
Fimbriae and Pili
Fimbriae and Pili are composed of a polymerized protein molecules called ________.
Pilin
How are Fimbriae and Pili different from flagella?
Fimbriae and pili are thinner than flagella, have a rigid structure, and are not associated with motility.
What is the function of Fimbriae and Pili?
They enable bacteria to anchor themselves to surfaces
Some bacteria possess a ________ for conjugation.
sex pilus
These are capable of forming thick-walled spores as a means of survival.
(1) Bacillus
(2) Clostridium
This is known as the process of spore formation; this is not necessarily reproduction.
Sporulation
These have been shown to survive for many years and are resistant to heat, cold, drying, and most chemicals
Spores
Usually one spore is produced in a bacterial cell, which generates into one _______________.
vegetative bacterium
Endospores can be visualized using a ___________.
spore stain
What is the difference between the cell membrane of eukaryotic and prokaryotic cells?
Eukaryotic cells contain membranous structures and many membrane bound organelles; most prokaryotic cells possess no membranes other than the cell membrane that encloses the cytoplasm.
This is the process by which prokaryotic cells reproduce. In this, one cell splits in half to become two daughter cells.
Binary fission
What happens before a prokaryotic cell divides in half?
Before a prokaryotic cell divides in half, the chromosome must be duplicated
This is the time it takes for binary fission to occur
Generation time (varies from one species to another and depends on growth conditions_
What is the generation time of Escherichia coli?
Escherichia coli has a generation time of about 20 minutes
This is the science of classification of living organisms.
Taxonomy
Taxonomy consists of what?
(1) Classification
(2) Nomenclature
(3) Identification
This is the arrangement of organisms into taxonomic groups (known as taxa).
Classification
What is the sequence of Taxa?
“King David Came Over for Good Spaghetti”
(1) K for Kingdom,
(2) D for Division,
(3) C for Class,
(4) O for Order,
(5) F for Family,
(6) G for Genus, and
(7) S for species
The science of taxonomy was established based on the _________.
Binomial system of nomenclature.
What composes the binomial system of nomenclature?
(1) Genus
(2) Epithet
How is the genus abbreviated?
single capital letter
What does the abbreviation “sp” mean?
Single species
What does the abbreviation “spp” mean?
More than one species
What are the five kingdom system of classification?
- Bacteria and archaea—Kingdom Prokaryotae
- Algae and protozoa—Kingdom Protista
- Fungi—Kingdom Fungi
- Plants—Kingdom Plantae
- Animals—Kingdom Animalia
Why are viruses not included in the five kingdom system of classification?
Viruses are not included because they are acellular.
What is the three domain system of classification?
- Archaea (prokaryotic)
- Bacteria (prokaryotic)
- Eucarya (all eukaryotic organisms)
The three domain system of classification is based on what?
The Three-Domain System is based on differences in the structure of certain ribosomal RNA (rRNA) molecules among organisms in the three domains.
The most widely used technique for gauging diversity or “relatedness” of organisms is called _______________.
rRNA sequencing
Ribosomes are composed of two subunits namely:
(1) Small subunit
(2) Large subunit
This subunit is composed of only one rRNA molecule
Small subunit
The small subunit is coded by a gene called ________ in prokaryotes
16s rRNA
The small subunit is coded by a gene called ________ in eukaryotes
18s rRNA
How do you determine the relatedness among organisms?
To determine how closely related one prokaryotic organism is to another, scientists compare the sequence of nucleotide base pairs in the 16S rRNA gene from one of the organisms with the sequence of base pairs in the16S rRNA gene from the other organism.
The more similar the sequence of base pairs, the more closely related are the organisms.
