The four processes of life
Growth, reproduction, responsiveness, and metabolism
Growth
Living things can grow; that is, they can reproduce
Reproduction
Organisms increase in number, producing more like themselves
Responsiveness
Living things ability to respond to their environment
Metabolism
Organisms ability to take in nutrients and use them in a series of controlled, chemical reactions to provide the energy and structure needed to grow, reproduce, and be responsive. Cells store metabolic energy in the chemical bonds of adenosine triphosphat
First chemical similarity between Prokaryotes and Eukaryotes: "they both contain...
They both contain nucleic acid, proteins, lipids, and carbohydrates.
Second chemical similarity between prokaryotes and eukaryotes: "they use the same kinds of...
They use the same kinds of chemical reactions to metabolize food, build proteins, and store energy.
Prokaryote chief distinguishment: "DNA
Their DNA is not coated within a membrane and is one circular chromosome. Also their DNA is not associated with histones (special chromosome proteins found in eukaryotes)
Prokaryote chief distinguishment: "they lack...
They lack membrane enclosed organelles.
Prokaryote chief distinguishment: "their cell walls...
Their cell walls almost always contain the Complex polysaccharide peptidoglycan
Prokaryote chief distinguishment: "they divide by...
They divide by binary fission. During this process, the DNA is copied and cell splits into two cells.
Eukaryotes chief distinguishment: "DNA
Their DNA is found in the cells nucleus, which is separated from the cytoplasm by a nuclear membrane, and the DNA is found in multiple chromosomes. Also, their DNA is consistently associated with chromosomal proteins called Histones.
Eukaryotes chief distinguishment: "They have a number of...
They have a number of membrane-enclosed organelles, including mitochondria, endoplasmic reticulum, Golgi complex, lyosomes, and sometimes chloroplasts.
Eukaryotes chief distinguishment: "Their cell walls...
Their cell walls, when present, are chemically complex.
Eukaryotes chief distinguishment: "They usually divide by...(which is guided by)
They usually divide by mitosis, in which chromosomes replicate and an identical set is distributed into each of two nuclei. This process is guided by the mitotic spindle, an assembly of micro tubules. Division of the cytoplasm and other organelles follows
Prokaryotic Cells
They include bacteria and archaea. Although bacteria and archaea look similar, they are different in chemical composition. The membranes of this world make up a vast heterogeneous group of very small unicellular organisms.
Differentiating Factors of Bacteria
Morphology, Chemical composition, Nutritional requirements, Biochemical activities, and Source of energy.
Three common shapes of Bacteria
Coccus (berry), Bacillus (rod-like), and Spirial
Cocci
These are usually round, but can be oval. When cocci divide to reproduce, the cells can remain attached to one another.
Diplococci
Cocci that remain in pairs after dividing
Streptococci
Cocci that divide and remain attached in chain-like pairs
Tetrads
Cocci that divide in two planes and remain in groups of four.
Sarcinae
Cocci that divide in three planes and remain attached in cube-like groups of eight.
Staphylococci
Cocci that divide in multiple planes and form grape-like clusters.
Bacilli
These divide only across their short axis, thus there are fewer groupings of these then cocci. Most of them appear in single rods.
Diplobacilli
Bacilli that appear in pairs after division.
Streptobacilli
Bacilli that occur in chains.
Coccobacilli
Bacilli that look like cocci
Spiral
These bacteria have one or more twists; they are never straight.
Vibrios
Bacteria that look like curved rods.
Spirilla
Bacteria that have a helical shape, like a corkscrew, and fairly rigid bodies. These use whiplike extermal appendages called flagella to move.
Spirochetes
Another group of Bacteria spirals that are helical and flexible. These move by means of axial filaments, which are contained within a flexible, external sheath.
Additional shapes of Bacteria
Star shape, Rectangular, and Triangular.
What is shape of Bacteria determined by?
Heredity
Monomorphic
Bacteria that maintain a single shape. Genetically, bacteria are mostly this shape.
Pleomorphic
Bacteria that have a number of shapes. Rhizobium and Corynebacterium are examples.
External structures of Prokaryotic cell walls:
1.) Glycocalyx, 2.) Flagella, 3.) Axial filament, 4.) Fimbriae, 5.) Pili
Glycocalyx
The term means "sugar coat." it is a general term referring to substances that surround cells. The bacterial is a viscous (sticky), gelatinous polymer that is external to the cell wall and composed of polysaccharides, polypeptide, or both. Its chemical co
Slime Layer
if the substance is unorganized and only loosely attached to the cell wall, the glycocalyx is described as this.
What can a glycocalyx protect a cell against?
It can protect a cell against dehydration, and its viscosity may inhibit the movement of nutrients out of the cell.
Virulence
This term refers to the degree to which a pathogen causes disease.
Capsule
When the substance is organized firmly attached to the cell wall, a glycocalyx is described as this. These are important to contributing to virulence in bacteria. They often protect pathogenic bacteria from phagocytosis by cells of the host.
Three examples of Capsule containing bacteria.
1.) Bacillus Anthracis, 3.) Streptococcus Pneumoniae, 3.) Klebsiella Pneumoniae
Bacillus Anthracis capsule produced
D- glutamic acid. Because only encapsulated B. anthracis causes anthrax, it is speculated that the capsule may prevent it from being destroyed.
Streptococcus Pneumoniae capsule produced
Streptococcus causes pneumonia only when the cells are protected by a polysaccharide capsule. On the other hand, unencapsulated S. pneumoniae cells cannot cause pnemonia since they are readily phagocytized.
Klebsiella
The polysaccharide capsule that also prevents phagocytosis and allows the bacterium to adhere to and colonize the respiratory tract.
Extracellular polysaccharide (EPS)
A glycocalyx made of sugars. This enables a bacterium to attach to various surfaces in its natural environment in order to survive. Through attachment, bacteria can grow on diverse surfaces such as rocks in fast-moving streams, plant roots, human teeth, m