Classification And Structure Of Prokaryotic Cells

Question 1

Prokaryotic cells

Answer 1

-do not contain membrane-bound organelles
-genetic material is organized into single circular molecule of DNA concentrated in the nucleoid region

Question 2

Archea

Answer 2

-single-celled organisms that look similar to bacteria, but contains genes and several metabolic pathways that are more similar to eukaryotes than porkaryotes
-considered extremophiles = isolated from harsh environments with high temps, high salinity, or no light
-ability to use alternative sources of energy
-hypothesized that eukaryotes and archea similar origin = both start translation with methionine, contain similar RNA Polymeraes, and have histones in their DNA.
-difference with archea is that they have a single circular chromosome, divide by binary fission or budding, and share similar structure as bacteria
-resistant to many antibiotics

Question 3

Bacteria

Answer 3

-cell membrane

Question 4

Bacteria

Answer 4

-all bacteria contain cell membrane and cytoplasm and some have flagella and fimbriae (similar to cilia)
-relationship between human body and bacteria: mutualistic symbiotes and parasite
-mutualistic symbiotes: both humans and bacteria benefit from the relationship
-pathogen/parasitic: no advantage or benefit to the host but instead cause the disease
-three different shapes: coci (spherical bacteria), bacilli, and spirilli
-aerobes vs anaerobes: aerobes = bacteria that uses oxygen; anaerobes= bacteria that doesn’t use oxygen, rather uses fermentation or other form of cell metabolism
-facultative anaerobes: switches between using oxygen and/or other forms of cell metabolism
-aerotolerant anaerobes: unable to use oxygen for metabolism but is not harmed by the presence of oxygen in the environment

Question 5

Prokaryotic cell structure

Answer 5

-no nucleus, no nuclear envelope
-no membrane-bound cell organelles
-single-celled organism = the cell must be able to perform all of the cellular functions on its own
-contains cell wall, cell membrane (made out of phospholipids like eukaryotes), ribosome, DNA (nucleoid region), and flagella
-cell wall + cell membrane = envelope
-cell wall: provides structure and controls the movement of solutes in and out of cells. Two types: gram positive and gram negative
-gram positive = staining is deep purple color; made from peptidoglycan and contains lipoteichoic acid
-gram negative = staining is pink-red color; smaller amounts of peptidoglycan

Question 6

Differences between prokaryotic vs eukaryotes

Answer 6

-prokaryotes don’t have a mitochondria, instead the cell membrane is used for the ETC and ATP generation
-prokaryotes contain cytoskeleton, but not as complex as eukaryotes
-prokaryotes contain ribosomes, but these are different than those found in eukaryotes because they are smaller in size