Term
| Describe the differences between phagocytosis, pinocytosis, and Receptor-mediated endocytosis |
|
Definition
Phagocytosis-grabs out to get food particle(pseudopodium) and brings in as food vacuole
Pinocytosis-plasma membrane creates a vesicle and grabs things nearby
Receptor-mediated Endocytosis- Calls a receptor to catch the ligand and brings it in a coated vesicle |
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Term
| What are lysosomes and are they acidic or basic? |
|
Definition
Membrane-bound pocket
containing hydrolytic
enzymes
Acidic |
|
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Term
| What are the functions of lysosomes? |
|
Definition
Process harvest from phagocytosis
Carry our autophagy(self digestion) |
|
|
Term
| How do lysosomes carry out autophagy? |
|
Definition
Digestion of old organelles
Recycle macromolecules |
|
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Term
| How do lysosomes process harvest from phagocytosis? |
|
Definition
Engulf organisms of food
into vacuole
Lysosome fuses with
vacuole
Contents are digested |
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Term
| What are 4 characteristics of the cell membrane? |
|
Definition
Segregate domains
◦ Serve as barrier to passage of some materials while
allowing passage of others
◦ Allow information to cross (signals)
◦ Provide a surface for organization |
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|
Term
| What is the membrane structure? |
|
Definition
◦ Phospholipid bilayer
◦ Also:
Cholesterol
Proteins
Carbohydrates |
|
|
Term
| What is the Fluid Mosaic model? |
|
Definition
◦ Fluid Mosaic Model
Membrane is mosaic of
phospholipid and
embedded proteins
Random distribution
Free mobility
Not entirely true –
subdomains: Lipid Rafts |
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|
Term
| Describe membrane fluidity? |
|
Definition
-Membranes are
dynamic – components
constantly moving
- Lateral movement
- Non-directed flipping from one side of bilayer rarely happens, not physiologically relevant |
|
|
Term
| What is membrane fluidity affected by? |
|
Definition
Temperature
Unsaturated vs.
saturated hydrocarbons
Cholesterol
Integral proteins |
|
|
Term
| What are the two types of membrane proteins? |
|
Definition
|
|
Term
| When a membrane protein is integral what does it mean? |
|
Definition
- Directly within membrane
Cross membrane (transmembrane)
Embedded in one side |
|
|
Term
| When a membrane protein is peripheral what does it mean? |
|
Definition
-Loosely attached
Associate with phospholipids
Associate with integral proteins |
|
|
Term
| What are the wide range of functions that membrane protein do? |
|
Definition
Transport
Enzymatic activity
Signal transduction
Cell recognition
Intercellular joining
Cytoskeletal attachment |
|
|
Term
| What targets for viruses? |
|
Definition
|
|
Term
| How do membrane proteins target viruses? |
|
Definition
Viruses infect cells by specific binding to cell-surface
proteins
Targets for immunological, pharmacological or genetic
intervention |
|
|
Term
| What are the products of the endomembrane system? |
|
Definition
|
|
Term
| Describe how the transmembrane proteins are made? |
|
Definition
Soluble proteins will be secreted, trans-membrane proteins will
remain in plasma membrane or within the endomembrane
system |
|
|
Term
| Describe membrane permeability |
|
Definition
◦ Selectively permeable, based on size, hydrophobicity
Easily cross: small, uncharged non-polar
Do not easily cross: large, hydrophilic (charged/polar) |
|
|
Term
| What is diffusion and how does it happen? |
|
Definition
◦ Random movement of molecules toward equilibrium
-molecules spread out in space
◦ From High concentration to Low
- ‘Down’ concentration gradient |
|
|
Term
| What is osmosis and how does it occur? |
|
Definition
◦ Diffusion of water across selectively permeable membrane
High water concentration to low
Low solute concentration to high |
|
|
Term
|
Definition
Ability of surrounding solution to cause a cell
to gain or lose water (through osmosis) |
|
|
Term
| What are the terms for hypotonic, isotonic, and hypertonic cells in animals and plants? |
|
Definition
Animal Hypo-Lysed Iso-Normal Hyper-Shriveled
Plant Hypo-Turgid(normal) Iso-Flaccid Hyper-Plasmolyzed |
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|
Term
| What are the three types of transport in the plasma membrane, describe the types of energy required as well. |
|
Definition
Passive transport
◦ Diffusion across
membrane
No energy required
Facilitated Diffusion
◦ Passive transport via
proteins
No energy required
Active Transport
◦ Against concentration
gradient
Energy required (ATP) |
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|
Term
| What tends to happen to cells that are Hypotonic, Isotonic, and Hypertonic? |
|
Definition
Hypotonic solution will cause cell to gain water
fewer solutes in solution than in cell
Isotonic will cause no change
same level of solutes as in cell
Hypertonic solution will cause cell to lose water
more solutes than in cell |
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