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Biology 1134 Exam 2 Questions and
Answers (Expert Solutions)
Q: Transport proteins, 🗹🗹: -Allow for the movement of ions and hydrophilic
molecules across membranes.
-Transmembrane proteins
-Play major role in selective permeability of membranes
-2 types: Channels and Transporters
Q: Channels, 🗹🗹: -Transmembrane proteins
-Form open passageways across the membrane
-Function in facilitated diffusion of ions/molecules.
-Solutes move directly through to get to other side of membrane.
-Up to 100 ions/molecules per sec.
-Most are gated: opening and closing is regulated
-may involve non covalent binding of molecule to chemical protein
-Ex: Aquporin: water movement across membrane.
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Q: Transporters, 🗹🗹: -also called Carriers
-Transmembrane protein
-Binds solute in hydrophobic pocket
-Undergoes conformational change in shape
-Hydrophilic pocket pocket exposed to other side of membrane
-moves between 100-1000 molecules/ions per second
-Ex. of what is moved: organic molecules, hormones, neurotransmitters, waste
Q: Uniporters (Transporter), 🗹🗹: move 1 ion/molecule across membrane
Q: Symporters (Transporter), 🗹🗹: Move 2 or more ions/molecules across a
membrane in the same direction
Q: Antiporters (Transporter), 🗹🗹: moves 2 or more Ions/Molecules in the opposite
direction
Q: Active Transport, 🗹🗹: -Transport of solutes from areas of lower concentration of
the solute to areas of higher concentration.
-Move against their concentration gradient [Low] to [High]
-Energetically unfavorable
-requires an input of energy by the cell
Q: Primary Active Transport, 🗹🗹: -Requires a protein pump to move solutes
-can generate an electrochemical gradient across a membrane
-may be uniporter, symporter, or antiporter
-[Low] to [High]
Q: Protein Pump, 🗹🗹: A transporter protein that directly uses energy to move
solutes against their concentration gradient
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Q: Secondary Active Transport, 🗹🗹: -Uses pre-existing gradients to power active
transport of solutes
-Ex: a preexisting H+ electrochemical gradient drives the active transport of sucrose
Q: Exocytosis and Endocytosis, 🗹🗹: -Transport of large molecules and very large
particles (Ex: proteins, carbohydrates, bacteria)
-Include packaging of substances into vesicles or vacuole
Q: Exocytosis, 🗹🗹: -Material (cargo) within the cell is enclosed within a vesicle
-Vesicle moves to and fuses with plasma membrane
-Cargo is released outside of the cell
Q: Endocytosis, 🗹🗹: -The plasma membrane invaginate around material to be
incorporated into a cell
-A vesicle containing the material forms within the cell
Q: Receptor-Mediated Endocytosis, 🗹🗹: Membrane receptors bind specific
molecules (Ligands). (ex. Proteins, peptide hormones)
-Internal region of membrane binds within coat proteins
-Initiates membrane invagination and vesicle formation
-Vesicle is released into cell
-Usually vesicle fuses with membrane of an organelle
-recepter releases cargo
Q: Pinocytosis, 🗹🗹: -Form of endocytosis
-Cells to take in extracellular fluid
-Important in cells involved in nutrient absorption
- from the Greek, meaning "cell drinking"
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Q: Phagocytosis, 🗹🗹: -Very large vesicle, a phagosome, forms. (ex. macrophages
engulf bacteria).
-Phagosome moved into cell
-Fuses with Lysosome
- from the Greek, meaning "cell-eating"
Q: Metabolism, 🗹🗹: all chemical reactions occurring in an organism
Q: Energy, 🗹🗹: the ability to promote change or do work
Q: Kinetic Energy, 🗹🗹: energy associated with motion
Q: Potential Energy, 🗹🗹: energy an object possesses due to its structure or location
Q: Chemical Potential Energy, 🗹🗹: -Energy stored in chemical bonds
-may be released during chemical reactions
-Glucose stores great deal of potential energy
Q: Thermodynamics, 🗹🗹: The study of energy interconventions
Q: First Law of Thermodynamics, 🗹🗹: -Energy cannot be created or destroyed but
may be transferred or transformed from one form to another
-Explains the quality of energy
Q: Second Law of Thermodynamics, 🗹🗹: -As energy is transferred or transformed
from one form to another it is converted to a lower quality form.
-Increases the entropy (degree of disorder) in a system
-Explains the quality of energy
Biology 1134 Exam 2 Questions and
Answers (Expert Solutions)
Q: Transport proteins, 🗹🗹: -Allow for the movement of ions and hydrophilic
molecules across membranes.
-Transmembrane proteins
-Play major role in selective permeability of membranes
-2 types: Channels and Transporters
Q: Channels, 🗹🗹: -Transmembrane proteins
-Form open passageways across the membrane
-Function in facilitated diffusion of ions/molecules.
-Solutes move directly through to get to other side of membrane.
-Up to 100 ions/molecules per sec.
-Most are gated: opening and closing is regulated
-may involve non covalent binding of molecule to chemical protein
-Ex: Aquporin: water movement across membrane.
, Page | 2
Q: Transporters, 🗹🗹: -also called Carriers
-Transmembrane protein
-Binds solute in hydrophobic pocket
-Undergoes conformational change in shape
-Hydrophilic pocket pocket exposed to other side of membrane
-moves between 100-1000 molecules/ions per second
-Ex. of what is moved: organic molecules, hormones, neurotransmitters, waste
Q: Uniporters (Transporter), 🗹🗹: move 1 ion/molecule across membrane
Q: Symporters (Transporter), 🗹🗹: Move 2 or more ions/molecules across a
membrane in the same direction
Q: Antiporters (Transporter), 🗹🗹: moves 2 or more Ions/Molecules in the opposite
direction
Q: Active Transport, 🗹🗹: -Transport of solutes from areas of lower concentration of
the solute to areas of higher concentration.
-Move against their concentration gradient [Low] to [High]
-Energetically unfavorable
-requires an input of energy by the cell
Q: Primary Active Transport, 🗹🗹: -Requires a protein pump to move solutes
-can generate an electrochemical gradient across a membrane
-may be uniporter, symporter, or antiporter
-[Low] to [High]
Q: Protein Pump, 🗹🗹: A transporter protein that directly uses energy to move
solutes against their concentration gradient
, Page | 3
Q: Secondary Active Transport, 🗹🗹: -Uses pre-existing gradients to power active
transport of solutes
-Ex: a preexisting H+ electrochemical gradient drives the active transport of sucrose
Q: Exocytosis and Endocytosis, 🗹🗹: -Transport of large molecules and very large
particles (Ex: proteins, carbohydrates, bacteria)
-Include packaging of substances into vesicles or vacuole
Q: Exocytosis, 🗹🗹: -Material (cargo) within the cell is enclosed within a vesicle
-Vesicle moves to and fuses with plasma membrane
-Cargo is released outside of the cell
Q: Endocytosis, 🗹🗹: -The plasma membrane invaginate around material to be
incorporated into a cell
-A vesicle containing the material forms within the cell
Q: Receptor-Mediated Endocytosis, 🗹🗹: Membrane receptors bind specific
molecules (Ligands). (ex. Proteins, peptide hormones)
-Internal region of membrane binds within coat proteins
-Initiates membrane invagination and vesicle formation
-Vesicle is released into cell
-Usually vesicle fuses with membrane of an organelle
-recepter releases cargo
Q: Pinocytosis, 🗹🗹: -Form of endocytosis
-Cells to take in extracellular fluid
-Important in cells involved in nutrient absorption
- from the Greek, meaning "cell drinking"
, Page | 4
Q: Phagocytosis, 🗹🗹: -Very large vesicle, a phagosome, forms. (ex. macrophages
engulf bacteria).
-Phagosome moved into cell
-Fuses with Lysosome
- from the Greek, meaning "cell-eating"
Q: Metabolism, 🗹🗹: all chemical reactions occurring in an organism
Q: Energy, 🗹🗹: the ability to promote change or do work
Q: Kinetic Energy, 🗹🗹: energy associated with motion
Q: Potential Energy, 🗹🗹: energy an object possesses due to its structure or location
Q: Chemical Potential Energy, 🗹🗹: -Energy stored in chemical bonds
-may be released during chemical reactions
-Glucose stores great deal of potential energy
Q: Thermodynamics, 🗹🗹: The study of energy interconventions
Q: First Law of Thermodynamics, 🗹🗹: -Energy cannot be created or destroyed but
may be transferred or transformed from one form to another
-Explains the quality of energy
Q: Second Law of Thermodynamics, 🗹🗹: -As energy is transferred or transformed
from one form to another it is converted to a lower quality form.
-Increases the entropy (degree of disorder) in a system
-Explains the quality of energy
