BIO 100 EXAM#2 University of Maine Questions with 100% Verified Answers Latest Update

BIO 100 EXAM#2 University of Maine Questions with 100%
Verified Answers Latest Update

Question: Answer:
LECTURE#6 LECTURE#6
Cell Communication Cell Communication


Question: Answer:
The "gatekeeper" of the cell Plasma membrane
1. all cells have one
2. membranes are semi-permiable
3. separates the cell from its environment
4. biologically important molecules are transported cross the
membrane
5. hydrophobic phospholipid bilayer
6. Large molecules and charged molecules cannot pass through, but
small molecules,
and hydrophobic molecules can


Question: Answer:
Areas of abundance to scarcity Concentration of Gradients


Question: Answer:
1. "easier" Downhill energy Passive transport
2. Movement from high to low concentration
3. Requires no energy
4. Small moleculed diffuse through the membrane
5. Larger molecules and ions enter through protein carriers (Channel
proteins, some of
which can open and close, and carrier proteins)

,Question: Answer:
1. "harder" Uphill energy Active transport
2. Movement from low to high concentration
3. Requires added energy
4. Active carriers use energy from ATP
5. Energy changes the shape of the carrier
6. Energy produces a concentration gradient


Question: Answer:
Movement of molecules across a membrane, up a concentration Active carrier proteins
gradient. AC proteins
use energy from breakdown of ATP
EX) Sodium-potassium pump. Na+ and K+ are important for
metabolic functions


Question: Answer:
Water moving passively across a membrane Osmosis


Question: Answer:
Release of substances from the cell.Membrane-enclosed transport Exocytosis
vesicles fuse with the
plasma membrane, and the fusion causes release without destroying
the cell.


Question: Answer:
Inward budding of the membrane to form a vesicle. The opposite of Endocytosis
Exocytosis.
1. non-specific endocytosis: pinocytosis ('cell drinking'
2. specific endocytosis: receptor-mediated
a) particles must bind to receptor proteins; receptors select targeted
substances
b) only selected substances are pulled into the cell

, Question: Answer:
Ingestion of entire cells or "cell eating" Phagocytosis
1. Membrane receptors identify the bacterium
2. Pseudopodia extend around the bacterium
3. creates a food vacuole
EX) Ameobas consuming peramecium


Question: Answer:
Signaling molecules. Hydrophobic SM can cass freely through the Receptors for cell signaling
mambrane to
intracellular receptors, whereas Hydrophilic SM must bind to surface
receptors to affect
the cell.


Question: Answer:
What 7 places can receptors exist in relation to a cell? 1. Outside of the cell
2. On the cell's surface
3. Inside the cell
4. Other surfaces
5. In the form of signaling cascades
6. Inside the nucleus of the cells
7. In the form of activation genes


Question: Answer:
LECTURE#7 LECTURE#7
Energy and Enzymes Energy and Enzymes


Question: Answer:
The sum of all chemical reactions in the body. Transfers energy Metabloism
following the laws of
thermodynamics, primarily, the first 2 laws:
1. Energy can neither be created nor destroyed. Rather, it is
transferred
2. When reactions occur, they become more disordered. Entropy is
the variable that
explains disorder.