The Cell Flashcards
Nucleus
Contains DNA
Controls cellular activity
Plasma membrane
Regulates movement in/out of cell ( selectively permeable)
Phospholipid bilayer
Separates ECF (interstitial) & ICF (cytoplasm)
Ribosome
Site of beginning of protein synthesis
Nucleolus
Produces components of ribosomes (RNA & proteins)
Golgi
Sorts, modifies, packages proteins from RER, sends to destinations
Endoplasmic reticulum (2 types)
Channels surrounding nucleus
Types
-smooth
Contains no ribosomes
Filters drugs/alcohol/chemicals
Production of phospholipids
-rough
Contains ribosomes
Processes and modifies amino acid chains created in ribosomes, encloses in vesicles, sends to Golgi.
Lysosomes
Contains digestive enzymes
Breaks down worn out cell parts and bacteria
Mitochondria
Place for cellular respiration
Input: glucose
Output: ATP
Simple diffusion
Random movement of lipid-soluble substances across membrane in direction of concentration gradient (high>low)
Facilitated diffusion
Movement of water-soluble substances across lipid membrane with help from membrane proteins in the direction of the concentration gradient.
Carrier protein
Membrane protein which binds with water-soluble substance to carry it across the cell membrane.
Channel
Membrane protein which creates a pathway across cell membrane through which water-soluble substances can move.
Osmosis
Diffusion of water across a selectively permeable membrane from high to low concentration.
Hypertonic solution (definition and action on the cell)
A solution whose solute concentrate is higher than inside the cell.
Water moves from high concentration inside the cell to low concentration outside the cell and the cell shrivels.
Isotonic solution (definition and action on the cell)
A solution whose concentration of solutes is the same as inside the cell.
Cell exhibits no change.
Hypotonic solution (definition and action on the cell)
A solution whose concentration of solutes is less than that inside the cell.
Water moves from high concentration outside the cell to low concentration inside the cell and the cell swells.
Active transport
Mechanism moving substances across cell membrane using membrane proteins and ATP against concentration gradient.
Endocytosis
Method for moving large substances (bacteria) into the cell.
Plasma membrane engulfs substance, pinches off into a vesicle, which then travels through the cytoplasm.
Exocytosis
A method for removing large substances (hormones) from the cell.
Substance is enclosed in vesicle and delivered to plasma membrane.
Cytoskeleton (3 types)
Network of fires throughout cytoplasm
Types
- microtubules
- microfilaments
- intermediate filaments
Microtubules (3 functions, 2 types)
Straight hollow rods
Functions
- maintain cell shape
- create tracks for traveling organelles & vesicles
- help to separate chromosomes during cell division
Types
-cilia
Cell extensions on surface which move back and forth like oars, help with movement (ex. Move mucus and debris from lungs)
-flagellum
Whip-like cell extension which undulates, allowing movement. Sperm is only example in humans.
Microfilaments
Solid rods, best known for role in muscle contraction
Also have role in cell division
Intermediate filaments
Rope-like fibers
Maintain cell shape
Anchor organelles
More permanent than microtubules & microfilaments
Functions of membrane proteins (3)
- Regulation of movement of substances in/out of cell
- Communication between cells (receptor proteins)
- Structural support (bind cells together)
Types of structural proteins (3)
- tight junction
- adhesion junction
- gap junction
Tight junction proteins (function and example)
Function: form barriers (preventing movement between cells, allowing movement only through cells)
Example: intestine
Adhesion junction proteins (function and example)
Function: hold cells together but allow stretching
Example: skin
Gap junction proteins (function and example)
Function: allow communication (chemical/electrical) between cells
Example: heart
