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 nucleus

True

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 decreases

False, 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