Lecture 3 - Prokaryotic Cell Flashcards
all living things are made up of what?
cells
what are cells?
the smallest unit of life
what is the cell theory?
That all living things are made up of cells which are the smallest unit of life. All cells arise from pre-existing cells, which is called biogenesis which was coined by Louis Pasteur.
do all cells arise from pre-existing cells? what is the term that describes this?
yes; biogenesis
who is the scientist that came up with biogenesis?
Louis Pasteur
T/F: every cell has a plasma membrane
TRUE
what are the similarities between prokaryotes and eukaryotes?
They both have plasma membranes, ribosomes (which synthesize proteins), cytosol, and DNA (but the way the DNA is present is different)
all cells arose from what?
all cells arose from a common prokaryotic ancestor 3.5-4 billion years ago
what is the difference between the dates of origin between prokaryotic vs. eukaryotic cells?
-Prokaryotic cells: first evolved about 3.5 billion years ago
-Eukaryotic cells: first evolved about 2.1 billion years ago
what is the difference between the domains where they are found between prokaryotic vs. eukaryotic cells?
-Prokaryotic cells: Found in Bacteria and Archaea domain
-Eukaryotic cells: Found in protists, plants, fungi, and animals
what is the difference between the complexity between prokaryotic vs. eukaryotic cells?
-Prokaryotic cells: simple, small
-Eukaryotic cells: large, complex
what is the difference of the structures between prokaryotic vs. eukaryotic cells? do they have cell walls? what else do they have?
-Prokaryotic cells: most have cell walls. Some have capsules, fimbriae, and/or flagella.
-Eukaryotic cells: Plant cells have cell walls; animal cells are surrounded by an extracellular matrix.
do prokaryotic vs. eukaryotic cells have a plasma membrane?
-Prokaryotic cells: Yes
-Eukaryotic cells: Yes
what is the difference of the internal organelles between prokaryotic vs. eukaryotic cells?
-Prokaryotic cells: No membrane-bound organelles
-Eukaryotic cells: Membrane-bound organelles (nucleus, ER, etc.)
what is the difference between the DNA of prokaryotic vs. eukaryotic cells?
-Prokaryotic cells: DNA is free in a nucleoid location (with a single circular chromosome)
-Eukaryotic cells: DNA is within the nucleus (and with one or more linear chromosomes).
do prokaryotic vs. eukaryotic cells have ribosomes?
-Prokaryotic cells: Yes
-Eukaryotic cells: Yes
define morphology
the shape and arrangement of a cell
what is the coccus shape of the cell?
spherical
what are examples of coccus cells?
-Diplococci: in pair (Neisseria gonorrhoeae)
-Streptococci: in chain (Streptococcus pyogenes; strep throat)
-Staphylococci: in grape-like clusters (Staphylococcus aureus; HAIs like sepsis, pneumonia, etc.)
what is the rod shape of the cell? another name for it?
Bacillus - short and rod like
what are examples of rod (bacillus) cells?
-Coccobacillus: short rod
-Bacillus anthracis, E. coli, Clostridium tetani
what are vibrio shaped cells?
short curved rod
what is an example of vibrio cells?
Vibrio cholerae: cholera
what is spirillum shaped cells?
rigid long curved rod (more spirally)
what are examples of spirillum cells?
-Helicobacter pylori: stomach ulcers
-Campylobacter jejuni: diarrhea
what is the spirochete cells?
flexible long curved rod (longer but also spirally)
what are examples of spirochete shaped cells?
-Treponema pallidum: syphilis
-Borrelia burgdorferi: Lyme disease
what is the average size of a prokaryotic cell?
0.3-2 um (micrometer)
Name a vibrio-shaped bacterium and a disease it causes.
Vibrio cholerae causes cholera.
Name a spirochete-shaped bacterium and a disease it causes.
Treponema pallidum causes syphilis.
what are the components of a prokaryotic cell?
-Plasma membrane
-Cell wall (+/- meaning some have it but some don’t)
-Capsule (+/-)
-Flagella (+/-)
-Pili (+/-)
-Cytoplasm with cytosol, cytoskeleton, and internal structures including nucleoid
Plasma Membrane:
what are the structures of the plasma membrane? is it always present in the prokaryotic cell?
-phospholipid bilayer
-proteins
Yes, it is always present.
Plasma Membrane:
what are the functions of the plasma membrane?
-Protects and forms a border
-Semipermeable membrane
-Senses the environment using proteins
-Transports using proteins
-Energy production
Plasma Membrane:
which function is the most important of the plasma membrane?
Energy Production is the most important function! It creates energy in the plasma membrane. Prokaryotes don’t have mitochondria, which is the structure that makes energy.
So energy is produced here in the plasma membrane.
Plasma Membrane:
what are two ways of transport within the plasma membrane?
Passive and Active
Plasma Membrane:
what is passive transport?
When no energy is required and molecules go from high to low concentration - which is down the concentration gradient.
Plasma Membrane:
what are subtypes of passive transport?
-Simple diffusion: O2, CO2
-Facilitated diffusion: glucose (using the help of a protein)
Plasma Membrane:
what is osmosis? what type of transport is it?
Osmosis is the movement of water across a selectively permeable membrane.
It goes from less solute to more solute.
It is part of passive transport
Plasma Membrane:
what is isotonic solution?
When the solute in the cell = the solute outside of the cell.
There is no net water movement.
Plasma Membrane:
what is hypotonic solution? is there net water movement? what is the result?
It is when the solute concentration in the cell is greater and more than the solute concentration outside of the cell. There is net water movement toward the inside of the cell.
The result is lysis. The cell bursts.
Plasma Membrane:
what is hypertonic solution? Is there net water movement?
what is the end result?
It is when the solute concentration outside of the cell is greater than inside the cell.
There is net water movement toward the outside of the cell.
The result is plasmolysis and the cell shrinks.
Plasma Membrane:
what is active transport?
it is the opposite of passive transport. it transports molecules against the concentration gradient from low to high concentration.
It requires energy.
Give one similarity and one difference between simple and facilitated diffusion.
Simple and facilitated diffusion are both types of passive transport. However, simple diffusion doesn’t use the help of proteins, whereas facilitated diffusion does require proteins.
which of the following is NOT a function of the prokaryotic plasma membrane?
1. Protein production
2. Energy production
3. Osmosis
4. Protection
- Protein production; because ribosomes make protein and they are not located in the plasma membrane.
Cell wall:
where is the cell wall located?
is it always present in the prokaryotic cell?
Around the plasma membrane, surrounding it.
No, it isn’t always present.