Principles of Biology (Exam 2) Flashcards
Phospholipid bilayers are ____permeable
semipermeable
within the phospholipid bilayer, the heads are ____ while the tails are ____
heads are hydrophilic, tails are hydrophobic
what is amphipathic
molecules containing hydrophobic AND hydrophilic regions
What substances CAN move through the phospholipid bilayer
small, nonpolar molecules. Oxegyn, carbon dioxide, some water molecules
what substances CAN NOT move through the phospholipid bilayer
large, polar, water-soluble molecules; glucose, ions (H+, Na+, K+, etc.)
What are the tranposrt proteins that assist hydrophobic molecules through the phospholipd bilayer
channel proteins (for water: aquaporins, for ions: Ion Channels) and carrier proteins
define channel proteins (what are the two)
provide corridors that allow a specific molecule or ion to cross the membrane. Aquaporins, Ion channels
define carrier proteins
they undergo a subtle change in shape that translocates the solute-binding site across the membrane
What is diffusion
water moves from higher to lower concentration (greater the difference in concentrations, the greater the rate of diffusion; higher temperature does the same)
what is passive transport
What are the transport proteins that assist hydrophobic molecules through the phospholipid bilayer
channel(for water: aquaporon) and carrier proteins (
what is active transport (give ex)
requires energy (in form of ATP)
EX: Sodium potassium pump
what is osmosis and what are the 3 types
the movement of water from lower to higher concentration of a solution; hypertonic, hypotonic, isotonic
what is hypertonic
has higher concentration of solution; water will move towards it
what is hypotonic
lower concentration of solution; water will move away from it
what is isotonic
which organelle(s) in plant cells deals within maintaining turgid pressure
the vacuole and cell wall
plasmolysis
when the plant cell shrivels up
facilitated diffusion
specific proteins facilitate the passive transport of water and select solutes
what is co-transport
ATP powered pump + channel or carrier proteins, active transport + passive transport… ATP makes more efficient
what is endocytosis and the 2 types
importation of larger particles into the cell; phagocytosis and pinocytosis
what is exocytosis
things losing out of the cell… the cell releasing waste
what is phagocytosis
cell “eating”; bringing in whole particles
pinocytosis
cell “drinking”; absorbing liquids
plant cells become ____ in a isotonic solution
flacid
we want blood cells to remain _____
isotonic
what are the two types of energy
kinetic energy and potential energy
what is kinetic energy
the energy of movement (eg. light, heat, electricity, moving objects)
what is potential energy
stored energy (eg. chemical energy in bonds, battery, membrane potential, rock at top of a hill)
What is the 1st Law of thermodynamics
-the energy in the universe is constant
-energy is often transformed into heat
-energy can be transferred and transformed, but cannot be created or destroyed
What is the 2nd Law of thermodynamics
all energy transformations are inefficient- the amount of useful energy in the universe is decreasing and the amount of entropy (disorder) is increasing
What is entropy
measure of the energy not available for useful work in a thermodynamic process; disorganized, less order
What is free energy
𝝙G; energy available to do work in a chemical reaction
What is an exergonic reaction?
a release of energy; reactants contain more energy than products