Which of the following is not found in a prokaryotic cell?
E. mitochondrion.
Which of the fololowing can only be viewed with an electron microscope?
C. virus
The plasma membrane has the consistency of
A. olive oil
The plasma membrane is called a fluid mosaic because it contains
A. a mosaic of proteins suspended within a phospholipid bilayer.
Eukaryotic cells compensate for a low surface-to-volume ratio by
C. compartmentalizing their activities into organelles
Ribosomal subunits are prduced in which organelle?
A. nucleolus
Assist with cell-to-cell communication
C. channel proteins
Combine with molecules to carry them across plasma membranes
D. transport proteins
Combine with signaling molecules
E. receptor proteins
Participate in metabolic reactions
E. enzymatic proteins
Match - Ribosome
B. no membrane
match - Nucleus
C. double membrane
match - Lysosome
C. single membrane
match - mitochondrion
A. double membrane
The organelle that sorts proteins and sends them to their final destinations is the
A. Golgi apparatus
Plant vacuoles may contain
A. all of these are correct
The interior of a mitochondrion is called the
C. matrix
Which of these structures is involved in protein synthesis?
B. microtubles
Explain why a large surface-area-to-volume ration is needed for the proper functioning of cells.
A cell needs a relatively large surface area for efficient absorption of nutrients and secretion of wastes.
What is the major distinction between a prokaryotic cell and a eukaryotic cell?
A prokaryotic cell lacks a membrane-bounded nucleus, while a eukaryotic cell has one.
List the three types of bacterial appendatges. What do they have in common?
The three bacterial appendages are 1. flagella, 2. fimbriae, and 3. comjugation pili
They are all made of protein
Why is the plasma membrane described as a fluid mosaic?
The membrande is fluid because it has the consistency of oil; it is a mosaic because the many proteins form different patterns at various times in various membranes.
List six type of proteins found in the plasma membrane.
Channel
Transport
Cell recognition
Receptor
Enzymatic
Junction proteins
List the componets of the nucleus and give a function for each.
1. nuclear envelope: defines the nucleus
2. nuclear pore; allows substances to move into and out of nucleus
3. nucleus; produces ribosomal subunits
4. chromatin; becomes chromosomes and contains DNA, organized into genes.
Where are ribosomal subunits produced, and where do ribosomes form in the cell?
Ribosomal subunits are produced in the nucleolus and these subunits are assembled to form ribosomes in the cytoplasm. Many ribosomes are attached to the endoplasmic reticulum, and other occur freely within the cytoplasm.
Contract rough endoplasmic reticulum with smooth endoplasmic reticulum.
Rough ER contains ribosomes, while smooth ER does not. Rough ER synthesizes the polypeptides of proteins and modifies them, while smooth ER synthesizes lipids and detoxifies various chemicals, among other activites.
Describe the function of the Golgi apparatus.
The Golgi apparatus receives transport vesicles from the ER, modifies their contents if necessary, and repackages them in new transport vesicles that takes them to their destinations.
Compare the structure and function of chloroplasts and mitochondria.
Structure: the two main parts of a chloroplast are the thylakoids and the stroma; the two mains parts of the mitochondrion are the cristae and the matrix.
Function: Chloroplasts capture energy from the sun to build carbohydrates. Mitochondria break down mainly carbohydsrates to release energy for ATP production.
List the components of the cytoskeleton
Microtubles, intermedfiate filaments, and actin filabments.
What do motor proteins do?
Motor proteins move vesicles and organelles from one location to another along microtubules or can create movement by interacting with actin filaments.
Compare and contract the internal structure of centrioles with cilia and flagella
Centrioles, cilia and flagella are all composed of microtubles arranged in a particular pattern and enclosed by the plasma membrane.
In centrioles, the patern is 9 triplets with none in the center, while the arrangement of cilia and flagella is 9 doublets with two microtubules in the center.
Contract the primary cell wqall with the secondary cell wall in plants
All plant cells have a primary wall, which is capable of stretching during growth and is composed of cellulose and other compounds. The secondary cell wall has added strength and contains lignin in addition to cellulose.
Lignin adds rigidity but also strength to the cell wall.
Describe the composition of the extracellular matrix of an animal cell.
The extracellular matrix notably contains the fibrous proteins collagen and elastin. It also contains polysaccharides.
Compare adhesion junctions with tight junctions
Adhesion junctions are flexible because intercellular filaments join cytoplasmic plaques.
Tight junctions produce an impermeable barrier because plasma membrane proteins are joined to each other.
Describe the functions of gap junctions.
In gap junctions, plasma membrane proteins form channels that allow small molecules and ions to pass between two adjacent cells.