Cell communication

Question 1

Fluid Mosaic Model of Plasma Membrane

Answer 1

Phospholipid Bilayer, Proteins, Cholesterol

Question 2

Types of membrane proteins

Answer 2

transmembrane, integral, peripheral. Usually glycosylated

Question 3

Transmembrane Protein

Answer 3

Channel Proteins, Spans membrane

Question 4

Integral Proteins

Answer 4

Hydrophobic region that anchors it to the phospholipid bilayer. Usually has polysaccharides on it

Question 5

Peripheral Protein

Answer 5

Electrostatic, Not actually anchored

Question 6

Why is it important to separate inside and outside of the cell with plasma membrane?

Answer 6

Compartmentalization. Creates Gradients, islets nutrients

Question 7

Channel Protein

Answer 7

Allows polar, large molecules to pass through the plasma membrane. Form barrel in membrane. Very specific

Question 8

Carrier Proteins

Answer 8

Actually bind the thing trying to get through and cause conformational change, carries it through the membrane

Question 9

Porins

Answer 9

Holes in membrane that all simple diffusion. Not specific, not common in animal cells

Question 10

What is the significance in the membrane proteins being glycosylated?

Answer 10

Happens in Golgi and RER, recpetors, play role in signaling, for barriers

Question 11

What gives cell receptors their recognition capabilities?

Answer 11

Polysaccharides. On exterior of cell receptor where the ligand binds.

Question 12

Adhesion Proteins

Answer 12

Gap Junction, Tight Juction, Desmosomes, Plasmadesmata

Question 13

Gap Junctions

Answer 13

Nutrient exchange, cell-to-cell communication. Example is heart

Question 14

Tight Junctions

Answer 14

Encircle cells and adhere to cells around it. Seal extracellular space. Example is GI Tract

Question 15

Desmosomes

Answer 15

Spot welds between cells. Mechanical strength. example is Skin

Question 16

Plasmadesmata

Answer 16

Between plant cells. Open channels between the cells that allow nutrients to exchange

Question 17

Glycocalics

Answer 17

Carb Coating around a cell.Not all cells have this. More common in bacteria. Barrier to infection and help in adhesion for cell to cell communication

Question 18

Passive Transport

Answer 18

Doesn’t require ATP. With the concentration gradient. Simple and Facilitated diffusion

Question 19

Simple Diffusion

Answer 19

Passive. Right across the membrane, O2, CO2, lipids. Down concentration gradient

Question 20

Facilitated diffusion

Answer 20

Passive. Traveling down concentration gradient with the help of carrier protein, etc.

Question 21

Active Transport

Answer 21

Requires ATP. Primary and secondary

Question 22

Primary Active Transport

Answer 22

Across membrane and directly coupled with ATP hydrolysis. Na/K Pump

Question 23

Secondary Active Transport

Answer 23

Not coupled with ATP directly. Usually piggy backs off f Primary active transport and goes back down concentration gradient. Glucose/Na Symport

Question 24

Na/K Pump

Answer 24

3Na for every 2K.

Question 25

Resting Membrane Potential

Answer 25

-70mV in cell. Higher concentration of Na outside of cell and higher concentration of K inside the cell.

Question 26

What happens when ligand binds receptor?

Answer 26

Receptor undergoes conformational change that spans the membrane. signal transduction occurs. Activates G protein (peripheral) which activates Adenylate Cyclase (second messenger). Cascade effect

Question 27

What is the second messenger

Answer 27

Adenylate Cyclase

Question 28

What is osmosis

Answer 28

diffusion of water. high concentration to low concentration

Question 29

plasmolysis

Answer 29

destruction of cytoplasm (hypertonic)

Question 30

Cytolysis

Answer 30

destruction of cell (hypotonic)

Question 31

What can withstand hypotonic solution without bursting?

Answer 31

cell walls of plants and bacteria

Question 32

Phagocytosis

Answer 32

Cell eating (solids)

Question 33

Pinocytosis

Answer 33

Cell drinking (dissolved stuff)

Question 34

receptor mediated endocytosis

Answer 34

Triggered via receptors

Question 35

Microtubules

Answer 35

Largest. Made of Tubulin monomer, Form as cylinder in 9+2 fashion. Flagella/cilia. Make up spindle fibers

Question 36

Intermediate Filaments

Answer 36

Medium size. Shape and rigidity of cell

Question 37

Microfilaments

Answer 37

Smalles. Made of actin. Cellular motility. Cytokines (cell division)

Question 38

Which phase of the cell cycle is the longest?

Answer 38

Interphase

Question 39

What phases comprise interphase?

Answer 39

G1, S, G2

Question 40

Heterochromatin

Answer 40

Inaccessible to transcription

Question 41

Euchromatin

Answer 41

Accesible to transcription. loosely packed

Question 42

Prophase

Answer 42

Chromosomes condense, nuclear envelope disappears, centrioles (microtubule organizing center) migrate to opposite poles

Question 43

Metaphase

Answer 43

Chromosomes lined along the metaphase plate. Spindle fibers have attached to the centromeres of each of the chromosomes

Question 44

Anaphase

Answer 44

Sister chromatids pulled apart. Spindle Fibers shortening. Cleavage Furrow Forms

Question 45

Telophase/Cytokinesis

Answer 45

Nuclear membrane forms, cells completely divided.