Biology Test 1 - Lec 2

Question 1

dimerization:

Answer 1

when subunits join, monomers forming polymers

Question 2

phosphorylation:

Answer 2

a phosphate (PO43-) group binds to to a protein or other organic molecule, turns many protein enzymes on and off, thereby altering their function and activity.

Question 3

assay:

Answer 3

assessing or quantitatively measuring the presence or amount or the functional activity of a target entity

Question 4

polymerase:

Answer 4

enzyme that synthesizes polymers of nucleic acids

Question 5

peptide:

Answer 5

chain of amino acids

Question 6

The steps of signalling pathway

Answer 6

Signaling Pathway

1) signaling: signaling cell releases signal (small peptide or molecule)
2) receptor: signal binds to receptor (adjacent cell/same cell)
3) signal transduction: intracellular pathway activated, change expression of proteins inside cell
4) Response: cell responds according to signal>receptor>transduction message

Question 7

autocrine signaling:

Answer 7

when cells signal/communicate w/ themselves

examples: melanocytes and skin cell pigmentation, peptide released

Question 8

juxtacrine signalling:

Answer 8

• cells in direct physical contact communicating

- signalling molecule and receptors are on external membranes and touch directly

Question 9

examples of juxtacrine signalling

Answer 9

example: notch signalling in development (do we need to know this from E1a)

Question 10

paracrine signaling

Answer 10

cells that talk to neighbors (20 cell diameters distance)

Question 11

examples of autocrine signalling

Answer 11

examples: melanocytes and skin cell pigmentation, peptide released

Question 12

examples of endocrine signalling

Answer 12

pituitary release peptide into bloodstream, activates adrenal gland to produce cortisol (stress hormone)

Question 13

examples of paracrine

Answer 13

neurotransmitters (across synapse)

Question 14

kinase:

Answer 14

modifies other proteins by chemically adding phosphate groups to them

Question 15

phosphorylation:

Answer 15

adding phosphate to a protein, which causes a change in the protein (turn on and off)

Question 16

transcription factors:

Answer 16

affect gene experssion

Question 17

what chemicals are signaling molecules?

Answer 17

ligands, peptides, proteins

Question 18

Explain notch signaling:

Answer 18

signalling process where ligand proteins bind to the extracellular region, cleaving and releasing intracellular domain that enters the nucleus, modifying gene expression

Question 19

cAMP:

Answer 19

a second messenger that activates kinases and causes phosphorylation

Question 20

G Protein

Answer 20

intracellular portion of transmembrane receptor ??? details on slide 21 lecture 2

Hormone (extracellular) > G Protein > Adenylyl Cyclase > ATP > cAMP > transcription factors in DNA

Question 21

3 Types of Transmembrane Receptors

Answer 21

1) G Protein coupled receptors
2) receptor kinases
3) ligand-gated ion gated channels

Question 22

ECM

Answer 22

scaffolding, mostly made of polysaccarides

Question 23

3 Types of Junctions

Answer 23

Anchoring junctions, tight junctions, gap junctions

Question 24

what are four types of anchoring junctions

Answer 24

adherens junction: cell-to-cell junctions
desmosomes: intermdiate filament, cahderin
hemidesmosomes: intermedia filamen, integrin
focal adhesions: bind cell to ECM

Question 25

adherens junction:

Answer 25

cell-to-cell junctions, use cadherins

Question 26

focal adhesions:

Answer 26

bind cell to ECM, use Cadherins: two cadherins bind cell to ECM

Question 27

Explain the difference between cadherins and Integrins external and internal connections?

Answer 27

Cadherin: cell to cell adhesion, require Ca2+ ions Integrin: cell to ECM connection, no need Ca2+ both transmembrane proteins: external: cell to cell internal: connects cadherin to cytoskeleton

Question 28

Difference between extracellular and intracellular receptors

Answer 28

intra - iigand crosses membrane and binds within the cell extra: binds at receptor site on membrane

Question 29

Describe the acetylcholine receptor

Answer 29

respond to acetylcholine and possibly other signaling molecules

Question 30

Details of Protein Kinase Receptor

Answer 30

See page 23 Lecture 2

Question 31

What are the 3 changes that can in response to Signal Transduction

Answer 31

1) conformational change: (phosphorylation) 2) change in protein-protein interaction 3) degredation

Question 32

What are the adhesive proteins of the ECM

Answer 32

fibronectin - binds to integrin (anchoring junctions) integrin - bind to fibronectin laminin - major protein of basil lamina, structural founcation fo epithelial sheets in digestive track, epidermis, and endothelial cells

Question 33

fibronectin

Answer 33

- binds to integrin at anchoring junctions

Question 34

laminin

Answer 34

protein of basil lamina, major protein of basil lamina, structural foundation for epithelial sheets in digestive track, epidermis, and endothelial cells

Question 35

what are the structural proteins of ECM

Answer 35

collagen: main protein found in bone, cartilage, tendon elastin: elastic, expands and returns to shape

Question 36

collegen

Answer 36

main protein found in bone, cartilage, and tendon, ECM

Question 37

elastin

Answer 37

elastic, expands and returns to shape

Question 38

cadherin

Answer 38

cell to cell binding, self-ordering/self segregation (prefers like cells first)

Question 39

integrins

Answer 39

cell to extracellular matrix binding

Question 40

cell adhesion

Answer 40

connects cells to each other and ECM

Question 41

keratinocytes

Answer 41

cells found on basal lamina (protect against adjoining environment)

Question 42

epithelial:

Answer 42

layers of cells that line outside of body and inside of intestine, vessels

Question 43

basil lamina:

Answer 43

part of ECM that connects to cells via keratinocytes to underlies and support epithelial tissues

Question 44

connetive tissue:

Answer 44

few cells and lots of ECM

Question 45

dynamic instability:

Answer 45

constant breakdown and regrowth of cytoskeleton important for exploring space and restructuring, plus cell division

Question 46

desmosomes:

Answer 46

intermdiate filament, cahderin

Question 47

hemidesmosomes:

Answer 47

intermedia filamen, integrin

Question 48

Why was compartmentalization important in development of protobionts?

Answer 48

molecules are segregated and then replicate. If self-replicating molecules have capacity to catalyze the replication of OTHER molecules, compartmentalization reduces competition. Increases frequency of replication among specific molecules.

Question 49

What characteristics of life do viruses have, what characteristics don't they have?

Answer 49

Can: evolve (prone to mutation), respond to environment, Cannot: metabolize ( rely on host organisms)

Question 50

lytic vs lysogenic

Answer 50

lytic: different molecule w/in cell lysogenic: incorporates in cells DNA

Question 51

fibronectin:

Answer 51

mechanical linkage and focuses regulatory signals to specific integrin sites

Question 52

endothelial versus epithelial

Answer 52

endo - line blood vessels, and lymph system | epithelial: line the

Question 53

epithelial cells

Answer 53

line organs w/ cavities, Functions: secretion, selective absorption, protection, transcellular transport and detection of sensation avascular, so they must receive nourishment via diffusion of substances from the underlying connective tissue