A patient presents with blue sclera that results in an inability to form procollagen from pro-α chains. What disease does he have?
List the four main phases of mitosis in order.
Prophase, metaphase, anaphase, and telophase
When does mitosis occur in the cell cycle?
Mitosis occurs after G2 and before G1 in the cell cycle
When does DNA synthesis occur in the cell cycle?
After G1 and before G2 in the cell cycle
In this image, what two tumor suppressor genes normally inhibit G1-to-S progression?
Rb and p53
During which phase of the cell cycle can a cell enter G0?
Which phase of the cell cycle is usually the shortest?
Which phase of the cell cycle is shortened in rapidly dividing cells?
What is the relationship between cyclin-dependent kinases and cyclins?
Cyclins are regulatory proteins that are translated and activate cyclin-dependent kinases at appropriate times in the cell cycle
Permanent and stable cells are typically in which phase of the cell cycle?
Rb and p53 tumor suppressors prevent which transition in the cell cycle?
Transition from G1 to S phase; defective cells are not allowed to undergo DNA synthesis
_____ (Permanent/stable/labile) cells remain in G0 and regenerate from stem cells.
_____ (Permanent/stable/labile) cells enter G1 from G0 when stimulated.
_____ (Permanent/stable/labile) cells never go to G0 and divide rapidly with a short G1.
Neurons, skeletal and cardiac muscle, and red blood cells are examples of _____ (permanent/stable/labile) cells.
Hepatocytes and lymphocytes are examples of _____ (permanent/stable/labile) cells .
Name four examples of labile cells
Labile cells (bone marrow, gut epithelium, skin, and hair follicles)
What happens to cell cycling when there is a mutation in a tumor suppressor such as Rb or p53?
There is unrestrained growth in the cell, and thus an increased likelihood to develop a malignancy
List the three components of interphase.
G1, S phase, and G2
What are the main functions of the rough endoplasmic reticulum?
The synthesis of secretory (exported) proteins and the addition of N-linked oligosaccharides to proteins
Name two types of cells that are rich in rough endoplasmic reticulum.
Goblet cells (secrete mucus) and plasma cells (secrete antibodies)
What is the histologic term for rough endoplasmic reticulum in neurons? What substances are synthesized there?
Nissl bodies, which are the site of enzyme (such as ChAT) and neuropeptide synthesis
_____ (Free/Attached) ribosomes synthesize cytosolic and organellar proteins, whereas _____ (free/attached) ribosomes synthesize secretory proteins.
List two functions of the smooth endoplasmic reticulum.
Steroid synthesis and the detoxification of drugs and poisons
Give two examples of cells that are rich in smooth endoplasmic reticulum.
Liver hepatocytes and steroid-hormone-producing cells of the adrenal cortex
The Golgi apparatus functions as the distribution center for what?
Synthesized proteins and lipids
List three places to which the Golgi apparatus sends proteins and lipids.
The plasma membrane, lysosomes, and secretory vesicles
Clathrin is a protein that transports vesicles from the trans face of the Golgi apparatus to where?
Clathrin directs from trans-golgi to lysosomes and from plasma membrane to endosome
What type of protein-bound saccharides is modified in the Golgi apparatus?
N-oligosaccharides (on asparagine)
In patients with I-cell disease, the failure to add mannose-6-phosphate to proteins in the Golgi apparatus leads to what deficit?
There is no signal that targets lysosomal enzymes to the lysosome, resulting in exocytosis of the enzymes