Cell Signaling
What are the 3 stages of a signal transduction pathway?
Reception, transduction, response
What is homeostasis?
A stable equilibrium of the internal conditions in the body.
If there are 20 centromeres, how many chromatids are there?
40
What is Mrs. Lu's husband's first name?
Brandon
In direct signaling, how do animal cells communicate? Plant cells?
Plasmodesmata
What do the terms Stimulus, Receptor, Effector, and Response mean?
Stimulus: a variable that will cause a response
Receptor/sensor: sensory organs that detect a stimulus. This information is sent to the control center (brain)
Effector: muscle or gland that will respond
Response: changes (decreases or increases) the effect of the stimulus
What does a CDK do?
Phosphorylates a protein to regulate events in the cell cycle.
What is the main difference between a benign vs malignant tumor?
Benign stays in one area, malignant tumors can metastasize to other areas of the body.
What are second messengers?
Second messengers are small, non-protein molecules and ions help relay the message and amplify the response
○Cyclic AMP (cAMP) is a common second messenger
What is the difference between negative and positive feedback?
Negative feedback tries to calm the system down. Positive feedback increases the rate of whatever is happening.
What are the 3 stages of Interphase? Describe them.
G1 - cell is growing and making sure DNA isn't damaged
S - DNA is duplicating
G2 - cell continues to grow
What was Mrs. Lu's highest ACT composite score in high school?
30
What is the difference between paracrine and synaptic signaling?
Both are types of local signaling.
Paracrine signaling: secretory cells release local regulators (ie growth factors) via exocytosis to an adjacent cell
Synaptic: Occurs in animal nervous systems
●Neurons secrete neurotransmitters
○Diffuse across the synaptic cleft- space between the nerve cell and target cell
Come up with an example of positive feedback, and describe the process of what happens.
Examples: child labor, ethylene causing fruits to ripen, blood clotting, etc
What are the names of the 3 checkpoints, and what do they each check for?
G1: growth and no DNA damage
G2: DNA duplicated correctly and growing is still happening correctly
M: the spindle fibers have attached to the centromeres/kinetochores in metaphase
Name 2 internal cell cycle regulators and 2 external cell cycle regulators.
Internal: Cyclins, CDKs
External: growth factors, contact inhibition, and anchorage dependence
How do G protein coupled receptors work?
●Binds to a G protein that can bind to GTP, which is an energy molecule similar to ATP
Why can humans maintain their body temperature even when their environment around them is really cold or really hot?
Humans use negative feedback inhibition to help notice those changes in the environment. This way, they can keep their body temperature around the set point (98.6 F)
Draw the 5 stages of mitosis and label them.
Prophase, prometaphase, metaphase, anaphase, telophase
What is Mrs. Lu's favorite movie?
Pitch Perfect!