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26 Cards in this Set
- Front
- Back
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Functions of plasma membrane |
Isolates, regulates, communicates |
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Hydrophilic or hydrophobic A. Phospholipid head B. Phospholipid tail |
A. Hydrphyllic B. Hydrophobic |
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Membrane structure consists of |
1. Double layer of phospholipids in which proteins float
2. Lipids, isolate cell from surroundings 3. Proteins, regulate exchange of substances, communicate with environment |
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Which part of a phospholipid is polar and why?
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The head, due to nitrogen phosphate groups |
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Which part of the phospholipid is nonpolar? And why?
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The tale, due to chain of hydrogen carbon bonds
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Cholesterol role in membrane |
1. Makes bilayer stronger 2. Makes bilayer more flexible but less fluid 3. Makes bilayer Les permeable to water soluble substances 4. Flexibility allows for Sales to move without bursting apart |
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If a substance is polar can it pass through the hydrophobic area of a plasma membrane ? |
No |
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Most biological substances are polar or nonpolar?
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Polar |
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There are five types of membrane proteins, what are they?
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1. Transport proteins:channel proteins and carrier proteins 2. Enzymatic proteins 3. Signal transduction: receptor proteins 4. Cell recognition proteins: glycoproteins 5. Intercellular joining: gap junction and tight junctions |
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What do transport proteins do?
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1. Channel proteins- allows small molecules or particles to pass through the membrane, allows hydrogen ions to flow into the mitochondria, aquaPorins facilitate the passage of water. carrier proteins combine with a substance and help it move across the membrane, helps transport sodium and potassium ions across nerve cell membranes
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What do enzymatic proteins do?
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carry out metabolic reactions
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What do receptor proteins do?
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Has a shape that allows only a specific molecule to buy into it.
Molecule then changes its shape which causes the cell to respond The bodies organs are dependent on these proteins |
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What do glycoproteins do and give an example?
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Act as ID tags and cell surface attachment sites
Example- immune system cells recognize bacteria as "foreign" and initiate response to engulf and kill them |
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What do junction proteins do and give an example ?
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Forms junctions between cells
Example: allows molecules through to allow Cilia of cells that line respiratory tract to beat in unison |
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What are gap junction proteins, and give an example?
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Allows for communication between cells
Contains channels between cells to allow passage of hormones, nutrients, ions and even electrical signals between cells. Example- this is important in the heart and smooth muscles, it allows for the flow of ions that is required for the cells to contract as a unit |
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What are tight junctions and what do they do? Give an example?
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Proteins Make cells leakproof Made of the strands of proteins to keep spaces between cells from leaking Found in cells of tissues that serve as barriers Example-intestines, kidney, and the blood brain barrier |
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Plasma membrane is selectively what? Molecules that do cross the membrane do so by moving in response to what? |
Permeable
Concentration gradient |
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True or false Hydrophobic molecules, those that are soluble in lipids, can easily pass through the membrane |
True |
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Referring to the concentration gradient, do molecules tend to move from regions of high concentration to regions of low concentration? Or regions of low concentration to regions of high concentration?
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They tend to move from regions of high concentration to regions of low concentration
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Oxygen and carbon dioxide molecules move into and out of cells by passive or active transport?
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Passive |
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What is iso tonic and give an example? What happens to an animal and plant cell in this environment?
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The solution concentrations are the same on both sides of the membrane
Example- Iv fluid Animal cell is normal plant cell is flaccid |
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What is hypertonic and give an example? What happens to an animal and plant cell in this environment?
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The solution outside of the membrane has a higher concentration of solute which means a lower concentration of water
Salt water Animal cell is shriveled plant cell is plasmolyzed |
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What is hypotonic and give an example?
What happens to an animal and plant cell in this environment? |
The solution outside of the membrane has a lower concentration of salute, higher concentration of water
Drinking too much water Animal cell is lysed(explodes), plant cell is turgid (normal) |
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What is active transport? What type of protein uses active transport? Give an example?
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Cell uses energy to move substances against a concentration gradient
Transport proteins control direction of movement Example-in nerve and muscle cells salt is moved outside the cell wall potassium is moved inside the cell regardless of concentration |
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3 types endocytosis |
Pinocytosis,receptor mediated endocytosis,phagocytosis Pino-cell "drinking", rm-lock and key Phago- cell eating
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Endocytosis |
Bring something into cell |
