Term
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Definition
Key property of a plasma membrane; it allows some substances to pass through while keeping others out. |
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Term
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Definition
Phospholipids, proteins, cholesterol for animals, and carbohydrates |
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Term
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Definition
Structure of a membrane; a double layer of phospholipids, arranged tail to tail |
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Term
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Definition
Model of membrane structure where proteins float in a sea of lipids |
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Term
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Definition
Proteins that span the lipid bilayer and provide a pathway for substances to cross |
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Term
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Definition
The movement of a substance from an area of higher concentration to lower concentration due to the random motion of the molecules |
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Term
Which factors affect diffusion? |
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Definition
Temperature, pressure, concentration |
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Term
When does diffusion stop? |
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Definition
When the concentration is equal throughout |
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Term
What is dynamic equilibrium? |
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Definition
When particles are distributed equally; substance can still move but there is no more net change in concentration |
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Term
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Definition
A type of passive transport where a transmembrane protein helps to move substances across the membrane |
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Definition
A transmembrane protein that helps water molecules cross the membrane |
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Definition
The diffusion of water across a membrane |
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Term
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Definition
A homogeneous mixture formed when one substance is dissolved in another |
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Definition
The substance that is being dissolved like sugar or salt |
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Definition
The substance that is doing the dissolving like water |
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Definition
A solution that contains a high amount of solute and fewer free water molecules |
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Term
What happens to a cell in a hypertonic solution? |
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Definition
It will lose water and shrink. |
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Term
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Definition
A solution that has a small amount of solute and a large amount of free water |
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Term
What happens to a cell in a hypotonic solution? |
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Definition
It will gain water and swell. An animal cell may pop (hyPO = POp) |
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Term
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Definition
A solution that has the same amount of solute and free water molecules as the solution to which it is being compared |
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Term
What happens to a cell in a isotonic solution? |
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Definition
Its size will remain the same; molecules will cross the membrane in both directions but there will be no net change |
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Term
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Definition
Any process that uses energy to move substances across the membrane, usually against a concentration gradient, from low to high concentration. |
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Term
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Definition
A membrane protein that uses energy to pump 3 sodium ions out of a cell and 2 potassium ions into a cell |
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Term
Which type of cells have the sodium potassium pump in their membranes |
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Definition
It is found only in animal cells |
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Term
What is the net effect of the sodium potassium pump? |
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Definition
The inside of the cell gains a negative charge. |
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Term
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Definition
A cell surrounds a substance outside of the cell with arms of cytoplasm, engulfing it and drawing it inside, forming a vesice |
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Term
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Definition
The cell releases large molecules when a vesicle that contains these substances fuses with the cell membrane, dumping its contents. |
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Term
Which types of transport are passive? |
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Definition
Diffusion, facilitated diffusion and osmosis |
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Term
Which types of transport are active? |
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Definition
The sodium/potassium pump, endocytosis and exocytosis |
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Term
Which part of a phospholipid is hydrophilic? |
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Definition
The head or phosphate group likes water. |
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Term
Which part of a phospholipid is hydrophobic? |
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Definition
The tails of the phospholipid are the fatty acids and they hate water. |
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