PHSYL 201A - Cell Physl

Created by Ameera Gani

Interior of the cell consists of?
- Nucleus - Cytoplasm (outside nucleus)

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TermDefinition
Interior of the cell consists of?- Nucleus - Cytoplasm (outside nucleus)
Functions of plasma membrane- Physical Barrier - Cell communication - Structural support - Transport
Structure of a phospholipid- POLAR head - faces environment - NONPOLAR tail (unsaturated tail = DB = kink) - faces core
Purpose of steroids Maintain membrane fluidity (prevents FA's from packing together = decreases fluidity)
Membrane proteins: purpose of integral (intrinsic) proteins- ion channels/transporters
Membrane proteins: purpose of peripheral (extrinsic) proteins- inner or outer surface of membrane
Membrane proteins: purpose of glycoproteins - protein w/ attached carb - extracellular of plasma membrane
T/F: Lipids are responsible for selective permeability of the cell False, proteins are
Cell junctions: components of desmosomes - adhering junctions: anchor cells, structural integrity - plaques: anchoring point for cadherins - cadherins: link cells - intermediate filaments: anchor surface of desmosomes to cells, structural
Cell junctions: components of tight junctions & where's it found- found in epithelial tissue - occludins: impermeable, linking adjacent cells
Cell junctions: components of gap junctions- connexons: electrically couple cells
Components of the nucleus- chromatin: DNA for proteins (condensed = chromosome) - nuclear envelope - nuclear pores - nucleolusL makes rRNA
T/F: RBC's have no nucleusTrue
T/F: skeletal muscle cells have 1 nucleus False, they are multinucleate
Function and components of ribosome- no membrane - protein synthesis (has small and large subunits) - functional ribosomes: free in cytoplasm or bound to ER
Function of rough ER- granular (ribos bound to surface) - sacs - synthesize proteins (post-translational modification)
Function of smooth ER- agranular - branched - synthesize lipids, store Ca, detoxify drugs
Function and components of golgi apparatus- cisternae: membrane bound sacs - post-translation modification of proteins in Rough ER (packaged into vesicles) and secreted via exocytosis
Function of lysosomes- digestive enzymes - degrade debris (recycle)
Function of peroxisomes- oxidative enzymes (removes H from molecule)
Function of mitochondria- cell resp - have own DNA: double stranded circular DNA
Function and components of cytoskeleton- non membrane bound - maintain cell shape
Steps of Phagocytosis- cell eating: extension of plasma - ex: WBC 1. recognize bacteria 2. attachment of bacteria to phagocyte 3. pseudopodia ingest bacteria into phagosome 4. fuses lysosome with phagosome = phagolysosome 5. destruct bacteria via digestion enzymes 6. release end products via exocytosis
Pinocytosis- indentation of plasma membrane - nonspecific proces
Steps of receptor-mediated endocytosis 1. receptors bind ligands 2. clathirin forms pit and concentrates to make vesicle 3. vesicle travels
T/F: as size of concentration gradient increases, rate of transport decreasesFalse, rate of transport increases (greater force)
Factors influencing rate of diffusion (passive) - magnitude of force: increased conc = increased mag - membrane surface area - permeability: Smaller/regular shape is better for them to get in Temperature: higher is better Distance: smaller distance = faster rate
Osmosis Water: high to low conc - need active transport to alter water movement - flows from solution with lower solute to higher solute
Carrier mediated facilitated diffusion - no energy - high to low - GLUT (glucose: high -> low)
Channel mediated facilitated diffusion - no energy - selective - voltage/ligand/mechanically gated
Primary active transport- Na/K pump
Secondary active transport - cotransport: two substances in same direction (ex. Na/Glucose) - Countertransport: two substances in opp directions (ex. Na/H) - electroneutral: no net movement of charge
Properties of receptors- specificity - saturation - affinity - plasma membrane (is it transmembrane) - intracellular
Intracellular receptors- alters transcription of mRNA - alters rate of protein synthesis
Examples of water-soluble chemical messengers hormones, neuroT's - cannot cross plasma membrane
mechanism of receptors that are ligand-gated ion channels - first messenger binds to receptor = opens ion channel - ions cross membrane - change in electrical properties