Feedback Loops
What term describes the stability of an organism's internal environment maintained through a dynamic equilibrium
Homeostasis
Most biological catalysts that speed up metabolic reactions without being permanently altered belong to which class of macromolecules?
Proteins (Enzymes)
Passive transport requires no extra cellular energy because molecules move in which direction relative to the concentration gradient?
down the concentration gradient (high to low concentration)
Active transport requires extra cellular energy (ATP) because molecules are moved in what direction relative to the gradient?
against the concentration gradient (low to high concentration)
What general term refers to specific molecules that bind to receptor proteins for signaling purposes?
Ligands
In this type of feedback loop, the output (or product) intensifies the response to cause amplification.
Positive Feedback Loop
What process occurs when the output of a metabolic pathway is used as an input to control and inhibit the overall process?
Feedback Inhibition
What is the specific term for the simple diffusion of water across a cell membrane?
Osmosis
Active transport using membrane vesicles to move large particles INTO the cell is called what?
Endocytosis
Which chemical signal classification involves hormones traveling through blood vessels to distant target cells?
Endocrine signaling
Name the four essential components present in all feedback loops.
Receptor, Stimulus, Effector, and Response
Name two environmental conditions that can cause an enzyme to undergo denaturation.
pH and Temperature
Facilitated diffusion helps large or polar molecules cross the membrane; name the two types of transport proteins used.
Channel proteins and Carrier proteins
Nerve cells secreting neurotransmitters out of the cell to send signals throughout the body is an example of which bulk transport process?
Exocytosis
Differentiate between autocrine, paracrine, and juxtacrine chemical signals based on target cell location.
Autocrine affects self/same cell, Paracrine diffuses to nearby cells, and Juxtacrine requires direct contact
During thermoregulation when body temperature is too high, what organ acts as the receptor and what response occurs in the capillaries?
the Hypothalamus (receptor) and Capillary Dilation / Sweating (response)
How do chemical inhibitors regulate enzyme-catalyzed metabolic pathways?
by binding to enzymes to slow down reaction rates
What happens to a cell placed in a hypertonic solution, and why?
It shrivels because water concentration is lower outside the cell
In the Sodium-Potassium pump, how many of each ion are moved across the membrane per 1 molecule of ATP used?
three Na+ ions moved OUT and two K+ ions moved IN
Why do intracellular receptor ligands need to be small/nonpolar, whereas membrane receptor ligands are large/polar?
small/nonpolar ligands diffuse across the membrane, while large/polar ligands cannot cross
In blood sugar regulation, which specific pancreatic cells release glucagon when blood glucose levels drop too low?
Alpha cells in the pancreas
Cells control metabolism by switching enzyme synthesis on or off; what does a catalyst NOT do to a reaction?
It does not make a reaction occur that cannot otherwise occur
If a cell (15% NaCl, 85% H2O) is placed in an environment with 5% NaCl and 95% H2O, what solution type is the environment and what happens to the cell?
Hypotonic solution and the cell will swell
Give an example from the notes of a human cell using endocytosis to maintain homeostasis.
white blood cells engulfing bacteria to fight infection
During signal transduction, which enzymes add phosphate groups (phosphorylation) and which enzymes remove them (dephosphorylation)?
Kinases (add phosphate) and Phosphatases (remove phosphate)