Prokaryotes Flashcards
What is the three-kingdom classification of life?
Bacteria, Archaea and Eukarya
What are the main structures in a Prokaryote?
- An outer layer of the capsule
- Cell wall under the capsule
- Plasma membrane as the inner layer
- Cytoplasm filling the inside of the cell
- Nucleoid which is the genetic material or DNA of the cell
- Brown spherical structures called ribosomes
- Plasmid which contains extra genetic material or DNA
- Several small thread-like structures (pili) are present over the capsule. Each one is called a pilus.
- Two long thread-like structures emerging from cytoplasm are called flagella.
What is seen when a cell-wall of a gram-positive bacteria?
Gram-positive bacteria have only a single membrane that is covered by a thick peptidoglycan wall.
Teichoic and Lipoteichoic acids extend through the peptidoglycan layer and to the outer surface
What is seen when a cell wall is gram-negative in a bacteria?
gram-negative bacteria have two membranes: the outer membrane and inner membrane and between them a periplasmic space.
What is the mechanism of the Flagellum?
The long part extruding from the cell and responsible for cell movement is called the filament which is made up of the protein flagellin. The filament is attached with a hook to a rotating rod
What is the function of the Flagellum?
Flagella are filamentous protein structures found in bacteria, archaea, and eukaryotes, though they are most commonly found in bacteria. They are typically used to propel a cell through liquid (i.e. bacteria and sperm).
Where is the DNA found in Prokaryotes?
Nucleoid
What is the Nucleiod?
Is the space within a prokaryotic cell where the genetic information, called the genophore
what are the diverse environments prokaryotes can live in?
Soil, Water and Human body
What is Archaea?
Often found in extreme environments, utilise various energy sources: light, metal ions, hydrogen
What is Bacterial diversity?
based on SSU rRNA sequences
What are the three global nutrient cycles that prokaryotes drive from?
The Carbon Cycle, The Nitrogen Cycle, and The Sulphur Cycle
What is the difference between prokaryotes and eukaryotes?
Prokaryotes have a circular genome, while eukaryotes have a linear genome
Describe how the prokaryotic cells appear compared to the eukaryotic cells?
The prokaryotic cells are much smaller than the eukaryotic cells
How many kingdoms of life are currently recognised?
Three: bacteria, archaea, and eukaryotes
Why is rDNA used to measure evolutionary time?
It mutates extremely slowly and it is universally present in all organisms
Which kingdom is the most diverse?
Bacteria
What is the main constitute of the cell wall of gram-positive bacteria?
peptidoglycan
which of these statements describes why E. coli is Gram-negative?
Crystal violet is washed out of the cell by ethanol
What is the organelle called that is responsible for swimming behaviour in bacteria?
flagellum
Both, bacteria and eukaryotes have a cytoskeleton. T or F
True
Which properties make Archaea more difficult to study in the lab than true bacteria?
Archaea live under environmental conditions that are difficult to reproduce in the lab
Differences between Archaea and bacteria
The DNA of Archaea is organised into chromosomes and bound by histones, whereas bacteria have neither.
Lipids in the plasma membrane of Archaea are ether-linked, whereas the lipids of bacteria are ester-linked
Which group of Archaea is closed related to eukaryotes?
Heimdallarchaeota
What is not a function of plasma membrane?
being freely permeable to all molecules
In a lipid bilayer, [insert correct answer] fatty acid tails face each other within the bilayer and form a region that excludes water.
hydrophobic
Gases such as oxygen and carbon dioxide cross the plasma membrane by…
passive diffusion
Simple diffusion is the tendency of molecules to move:
down their concentration gradient
Which of the following is a vesicle mediated transport mechanism?
exocytosis
what property of the phospholipid molecule provides for some fluidity of the plasma membrane?
unsaturated hydrocarbon cis-double bonds leading to kinked tail
When a cell is exposed to hypertonic medium, its protoplast (membrane enclosed cytoplasm ) will swell. T or F
False
How is the asymmetry of the plasma membrane generated?
through the unequal distribution of specific lipids
How does the presence of internal membranes affect the evolution and functions of eukaryotic cells?
Functions are compartmentalised and trafficking between compartments is important
Which compound do methanotrophous bacteria live on?
CH4
what is mostly to be found in a inner layer of the lipid bilayer?
fatty acids
if you wanted to reduce the amount of cholesterol in your diet, which of these food or food products would you exclude?
chicken
what is the process of denitrification
the reduction of nitrate to nitrogen
which is not a function of ER?
protein sulfation
which organelles does the cis-side of the Golgi communicate with via vesicle trafficking?
endoplasmic reticulum
why is the endoplasmic reticulum a network of membrane tubules band cisterns?
To keep transport pathways short between the site of protein production and all designations within the cell and to increase its surface to allow for more ribosomes to bind
why does the endoplasmic reticulum not correspond directly with the outside of the cell?
because the presence of the “Golgi lock”
in which export pathway from the Golgi apparatus are products stored before release?
regulated secretion pathway
what is the function of peroxisomes
oxygen reduction
what provides the energy for nuclear uptake of proteins?
RanGTP
what is the typical microtubule pattern of a basal body?
9x3
what is the purpose of the mitochondrial electron transport chain?
creating a proton gradient which can be used to generate ATP
which reaction takes place in hydrogenosomes
anaerobic production of ATP from pyruvate
which process is common between mitochondria and chloroplast
the creation of a proton gradient
