Eukaryotes Flashcards
What are the 5 phyla of Eukaryotic organisms?
Algae, protozoa, fungi, plants, animals
What structure is used for cellular locomotion?
Flagella (cilia are also used for locomotion in some protozoa)
What structure is used for moving substances along the surface of a cell?
Cilia
What is the difference between flagella and cilia?
Flagella are few and long.
Cilia are many and short.
What type of algae use flagella?
Euglena
What phyla of organisms often have cilia?
Protozoa (like paramecium)
What is an example of cilia in the human?
The respiratory tract is lined with cells that have cilia to move mucous and debris in the bronchial tubes to clear the lungs.
What is the difference between prokaryote and eukaryote flagella?
Prokaryotic flagella rotate, but the eukaryotic flagellum moves in a wavelike manner.
How are the flagella and cilia anchored to the plasma membrane? What do they consist of and how are they arranged?
Both flagella and cilia are anchored to the plasma membrane by a basal body, which consists of 9 pairs of microtubules arranged in a ring, plus another 2 microtubules in the center of the ring, an arrangement called a 9 + 2 array.
What are microtubules made of?
Microtubules are made up of a protein called tubulin.
Do most non-animal eukaryotic cells have cell walls?
Yes, although they are much more simple than prokaryotic cells.
What 3 phyla have cellulose in their cell walls?
Algae, fungi, plants
When would a eukaryotic cell have a glycocalyx?
When it has no cell wall and has direct contact with the environment.
What is a glycocalyx?
A sticky carbohydrate that strengthens the cell surface, helps attach cells together, and contributes to cell-cell recognition.
Do eukaryotic cells contain peptidoglycan?
No.
Do antibiotics such as penicillin and cephalosporin affect eukaryotic cells?
No, they only act against peptidoglycan, and are therefore safe for human cells.
Is the plasma membrane of a eukaryotic cell different than that of a prokaryotic cell?
The plasma membrane of eukaryotic and prokaryotic cells is very similar in function and structure.
Are all eukaryotic cell plasma membranes the same?
No; each cell membrane has different proteins and carbohydrates, which serve in cell to cell recognition.
Where do bacteria attach on a cell?
On the proteins and carbohydrates on the cell membrane.
What are sterols, and where are they found?
Complex lipids that are only found in eukaryotic cells (with the exception of Mycoplasma, which is a prokaryote that causes leprosy and tuberculosis).
What is the function of sterols?
Sterols help the membranes resist lysis from increased osmotic pressure.
What methods allow for substances to cross the cell membrane?
a. diffusion
b. active transport
c. endocytosis
What is endocytosis?
This occurs when a segment of the plasma membrane surrounds a particle, encloses it, and brings it into the cell.
What is it when the cell membrane projects a pseudopod (false foot), engulfs a particle to bring it in the cell?
Phagocytosis
Where is cytoplasm located in a cell?
- Inside the plasma membrane
- Outside the nucleus
What is the fluid portion of the cytoplasm called?
Cytosol
Only eukaryotic cytoplasm has a cytoskeleton, give 2 examples.
- Microfilaments
- Microtubules
What is a cytoskeleton?
It provides support and shape for the cell and assists in transporting substances through the cell.
Can cytoskeleton move the entire cell?
Yes, as in phagocytosis.
What is cytoplasmic streaming?
The movement of cytoplasm from one part of the cell to another to distribute nutrients.
Many of the important enzymes found in the cytoplasmic fluid of prokaryotes are contained where?
Within organelles of Eukaryotes.
How are organelles bound?
Some are bound by a membrane while others are non-membrane bound.
Name the membrane-bound organelles.
Nucleus ER Golgi Complex Lysosomes, Peroxisomes Vacuoles Mitochondria Chloroplasts
What are the two structures in a cell that are non-membrane-bound, and are therefore not considered to be organelles?
Ribosomes
Centrioles
Name the 4 characteristics of the nucleus.
Contains almost all of the cell’s hereditary information (DNA).
Surrounded by a double membrane called nuclear envelope.
Within nucleus has one or more nucleoli.
Contains some protein called histones.
What is the function of histones?
They are like spools that DNA wraps around to organize it.
What is chromatin?
A thread-like mass of dormant DNA.
During replication what shortens and thickens in to chromosomes?
Chromatin
Do Prokaryotes have Histones?
No.
Is the DNA of a prokaryote enclosed in a nuclear envelope?
No.
How do Eukaryotic cells replicate?
Mitosis and meiosis
Does this happen in prokaryotes?
No.
What is the endoplasmic reticulum (ER)?
An extensive network of channels which are continuous with the nuclear envelope.
What are the two types of ER?
Smooth and Rough
What is the rough ER?
The area that has ribosomes.
What is the function of ribosomes?
They are the sites of protein synthesis (protein factories).
What is the difference between rough and smooth ER?
Smooth ER does not have ribosomes.
What does smooth Endoplasmic Reticulum contain?
Unique enzymes to make Phospholipids, fats, and steroids such as estrogen and testosterone.
What function does the smooth ER in Liver cells perform?
The enzymes of smooth ER in the liver detoxify drugs.
Within the Golgi complex, what is the protein modified into?
glycoproteins, glycolipids, and lipoproteins
What are glycolipids?
A lipid containing carbohydrate groups.
What are glycoproteins?
Molecule that consists of a carbohydrate plus a protein.
What are lipoproteins?
Lipoproteins are molecules made of proteins and fat.
What part of the Golgi complex is the secretory vesicle detached from?
Golgi membrane
From the Golgi membrane, where is the protein delivered to?
Plasma membrane where they are discharged from the cell.
What two transportation methods do proteins use to leave the Golgi complex?
Secretory and storage vesicles.
What are the vesicles of the Golgi complex called?
Storage vesicles
What is an important vesicle that contains digestive enzymes?
A Lysosome
Describe the physical feature of a lysosome.
Membrane-enclosed spheres
What is the vesicle called that stores processed proteins or nutrients?
Storage Vesicle
What is the function of Lysosomes?
They are vesicles which contain as many as 40 different kinds of powerful digestive enzymes which digest bacteria that enter the cell.
What are the functions of vacuoles?
- Storage for nutrients such as proteins, lipids, sugars, water.
- Store wastes and poisons to prevent toxicity to the cytoplasm.
- Used to transport substances within a cell and transport substances to the outside of the cell.
What are Mitochondria?
Rod-shaped organelles which appear throughout the cytoplasm of most eukaryotic cells. They make most of the cell’s ATP. There can be as many as 2000 mitochondria in one cell.
Name the characteristics of Mitochondria?
Mitochondria have a double membrane; the outer membrane is smooth but the inner membrane is arranged in a series of folds called cristae.
The center is a semi-fluid substance called the matrix.
What is the purpose of the cristae in mitochondria?
Convolutions of the cristae provide an enormous surface area on which chemical reactions can occur.
Why are mitochondria so important to cells?
Mitochondria are called the powerhouses of the cell because of their central role in ATP production.
How are mitochondria semi-dependent of the cell?
Mitochondria contain their own ribosomes and DNA. They are able to replicate themselves and make their own proteins.
What is a theory of the origin of Mitochondria?
It is theorized that they evolved from bacteria millions of years ago, which have a symbiotic relationship within the organism.
Where are chloroplasts found?
Only found in algae and green plants.
What do chloroplasts contain?
They contain chlorophyll plus enzymes required for photosynthesis. They also have their own DNA like Mitochondria.
Are they capable of multiplying on their own within each cell?
Yes.
How do chloroplasts and mitochondria replicate?
By binary fission similar to bacteria.
What organelle contains enzymes that can oxidize various substances including alcohol?
PEROXISOMES
What is the end product of the oxidation reaction?
HYDROGEN PEROXIDE (H2O2)
What is catalase?
An enzyme made by peroxisomes that decomposes H2O2 (converts it into H2O + water) so it is safe within the cell.
What is the function of peroxisomes?
To digest bacteria that have invaded the cell.
Ribosomes are attached to which surface of the rough ER?
The outer surface or floating free in the cytoplasm.
What is the function of the Ribosomes in the cell?
They are the sites of protein synthesis in the cell.
Are the Ribosomes in eukaryotic cells larger or smaller than the Ribosomes in the prokaryotic cells?
They are larger (80S instead of 70S) and denser than ribosomes of prokaryotic cells.
What are the purposes of the proteins made by ribosomes?
They are either used inside the cell, or inserted into the plasma membrane or exported out of the cell.
Where are Centromes located?
Near the nucleus.
What is the purpose of the Centrome?
During mitosis they move the duplicated chromosomes towards opposite ends of the cell.
One circular chromosome, not membrane-bound.
PROKARYOTIC
No histones
PROKARYOTIC
No organelles
PROKARYOTIC
Peptidoglycan cell walls
PROKARYOTIC
Reproduce by binary fission
PROKARYOTIC
No true nucleus; no nuclear membrane
PROKARYOTIC
Glycocalyx present as capsule or slime layer
PROKARYOTIC
Plasma membrane has no carbohydrates and lack sterols.
PROKARYOTIC
No cytoskeleton
PROKARYOTIC
Ribosomes are small (70S)
PROKARYOTIC
Paired chromosomes, membrane-bound
EUKARYOTIC
Histones present
EUKARYOTIC
Organelles present: Golgi complex, ER, mitochondria, chloroplasts
EUKARYOTIC
Polysaccharide cell walls
EUKARYOTIC
Reproduce by mitosis
EUKARYOTIC
True nucleus; nuclear membrane; also has nucleoli
EUKARYOTIC
Present in some cells that lack a cell wall
EUKARYOTIC
Plasma membrane has carbohydrates and sterols
EUKARYOTIC
Has a cytoskeleton
EUKARYOTIC
Ribosomes are large (80S)
EUKARYOTIC
