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Flashcards in Cells Deck (51):
1

3 membrane protein types

1. peripheral = loosely attached, usually hydrophilic and held in place by H-bonds and electrostatic interaction, disrupted by change in ionic concentration/pH
2. integral = usually hydrophobic (interior of plasma membrane is lipid part of phospholipid bilayer); use detergent to destroy membrane and expose
3. transmembrane = form of integral, dif domains dif characteristics

2

function of membrane proteins - 8

1. channel - small charged/polar
2. recognition - glycoproteins (oligosac attached, ex: major-histocompatability on complex macrophage to distinguish between self and foreign)
3. ion channel - gated with voltage, ligand or mechanics (Pressure, Temp, Vibration)
4. porins - certain ions/small polar molecules, aquaporins in kidney/roots
5. carrier - shape change
6. transport - ATP/active or facilitated dif
7. adhesion - attach cells to neighboring cells, anchors for internal filaments/tubules (stability)
8. receptor - binding sites

3

cholesterol

rigidity to membrane of ANIMAL cells; sterols do same in plants and HOPANOIDS in prokaryotes; also, none in yeast

4

glycocalyx

carb coat that covers outer face of cell wall of some bacteria and outerface of PM; consitsts of glycolipids and glocoproteins -- adhesive abilities, barrier to infection or markers for cell-cell recognition

5

nucleus

chromatin = not condensed DNA; chromosome = condensed; 8 histones organize into nucleosome; nucleolous for ribosome synthesis (subunits not put togetehr until cytoplasm); double layer nuclear envelope/membrane with nuclear pores for transport of rRNA, ribosome subunits, dNTPs, proteins (histone, DNA pol); nucleoplasm not cytoplasm

6

nuclear lamina

dense fibrillar network inside nucleus; mechanical support, DNA rep/cell division/chrom organization regulation; intermediate filaments, membrane associated proteins

7

nucleoid

irregular shaped region of prokaryote that contains genetic material

8

cytoplasm

area including cytosol and organelles but not nucleus; cyclosis = streaming movement

9

cytosol

the gel, not the stuff suspended in it

10

ribosomes

60S + 40S = 80S (euk); 50S+30S=70S (pro); made of rRNA + proteins

11

ER, rough

has ribosomes -- creates glycoproteins by attaching polysaccharides to polypeptides as they are assembled by ribosomes, continuous with outer membrane of nucleus

12

ER, smooth

synthesizes lipids/steroid hormones for export; in liver - breakdown of toxic byproducts/drugs/toxins; can store ions (Ca2+ = sarcoplasmic ret)

13

lysosome

vesicle produced from golgi, digestive enzyme, low pH to function (so if an enzyme escapes, inactive in cyto), apoptotic function

14

golgi

transport, cis face for incoming vesicle and trans for outgoing secretory vesicles; cisternae = flattened sacs

15

peroxisomes

breakdown substances H2O2 + RH2 --> R + H2O; use H2O2 to oxidize substances; in liver and kidney; plant - modify products of photorespiration

16

glyoxysomes

peroxisome in germinating seed to breakdown stored FA to generate energy for growth

17

microtubules (MT)

tubulin, support/motility for cellular activities; spindle apparatus to guide chromosomes during division; flagella and cilia - 9+2 array (9pairs and 2 singlets in middle) - animals and lower plants (mosses, ferns)

18

intermediate filaments

support, maintain shape

19

microfilament (MF)

actin, motility - skeletal muscle, amoeba psuedopid, cleavage furrow

20

MTOC

MT organizing center; centrioles, basal bodies (base of cilia/flag); 9x3 array; plants have MTOCs but not centrioles because they divide by cell plate, not cleavage furrow

21

transport vacuole

move materials between organelles

22

food vaculole

temporary food storage, merge with lysosome to break down

23

tonoplast

membrane of central vacuole

24

central vacuole

large, most of plant cell interior; turgor pressue when full - rigidity; store nutrients and carry out lysosomal functions; tonoplast is membrane

25

storage vacuole

starch, pigments, toxic substances (nicotine)

26

contractile vacuoles

single celled organisms use these to collect and pump xs h2o out of cell, prevent bursting, active transport; in protista like amoeba/paramecia in hypotonic env

27

cell walls

in plants, fungi, bacteria, archaea; cellulose, chitin, peptidoglycans, polysaccharides; support, secondary cell wall can develop beneath primary

28

ECM

in animals. area between adjacent cells; beyond PM & glycocalyx; fibrous structural proteins, adhesion proteins & polysacs; support, bind to adjacent cells **collagen, most common, also integrin and fibronectin

29

plastids

found in plant cells. chloroplasts (photosyn); leucoplast (starch storage); chromoplasts (carotenoid storage) ** carotenoids serve two key roles in plants and algae: they absorb light energy for use in photosynthesis, and they protect chlorophyll from photodamage.

30

carotenoids

They serve two key roles in plants and algae: they absorb light energy for use in photosynthesis, and they protect chlorophyll from photodamage. xanthophyll (w/O2) and carotene

31

mitochondria

make ATP; fatty acid catobolism - beta-oxidation (beta-oxidation is the process by which fatty acid molecules are broken down in the mitochondria to generate acetyl-coA, which enters the citric acid cycle, and NADH and FADH2, which are used by the electron transport chain); circular DNA, own ribosomes, endossymbiotic theory

32

beta oxidation

eta-oxidation is the process by which fatty acid molecules are broken down in the mitochondria to generate acetyl-coA, which enters the citric acid cycle, and NADH and FADH2, which are used by the electron transport chain

33

cytoskeleton

MT (cil/flag), MF, intermediate fils; division and motility role in euks

34

plant in hypotonic soln
isotonic
hypertonic

hypo- vacuole swells, turgor pressure (water rushes in because low solute concentration out vs in)
iso- flaccid plant cells
hyper- plasmolyzed, cytoplasm is pulled away from the cell wall (fungal cells also remain turgid because of cell walls, animal cells burst -- cytolysis)

35

endomembrane system *what does it not include!

*no mitochondria/choloroplasts
-network of organelles and structures either directly or indirectly connected that function in transport of proteins/macromolecules in/out of cell, includes PM, ER, golgi, nuc env, lysosomes, vacuoles, vesicles, endosomes

36

brownian movement

particles move due to kinetic energy, spreads small suspended molecules throughout cytoplasm; random motion of particles suspended in a fluid (a liquid or a gas) resulting from their collision with the quick atoms or molecules in the gas or liquid

37

cyclosis/streaming

circular motion of cytoplasm around cell transport molecules

38

intracellular circulation, 3 components

1. brownian movement
2. cyclosis/streaming
3. ER - provides channel through cytoplasm, PM-->nuc membrane

39

extracellular circulation

diffusion & circulatory system

40

anchoring junctions

DESMOSOME- keratin filaments inside attach to adhesion plaques which bind adjacent cells together, providing mechanical stability, and hold structures together (animal cells, found in tissues with mechanical stress - skin epithelium, cervix/uterus)

41

tight junctions

completely encircles each cell and produces a seal that prevents passage of materials between cells, charactersistic of cells lining digestive tract where materials required to pass through cells into blood; ANIMALS; prevent passage of stuff through intercellular space so that materials must actually enter cells in order to pass through tissues

42

gap junction

narrow tunnels between animal cells- CONNEXINS- prevent cytoplasms of cells from mixing, but allow passage of ions and small molecules

43

plasmodesmata

narrow tunnels between plant cells; desmotubule - narrow tube of ER, exchange material through cytoplasms surrounding desmotubule

44

prokaryote, 5 traits

no nucleus, single circular naked DNA, 50S+30S=70S, cell walls = peptidoglycan (archaea = polysac, plant = cellulose, fungi = chitin); flagella are NOT from MT

45

bulk flow

collective movement of substances in same direction in response to force or pressure (blodo)

46

plasmolysis

movement of water out of cell that leads to its collapse (passive transport)

47

dialysis

diffusion of different solutes across selectively permeable membranes

48

countercurrent exhcange

diffusion by bulk flow in opposite directions

49

phagocytosis

active transport, undissolved solid -- WBC engulfs and PM wraps around

50

pinocytosis

active transport of undissolved liquid; PM invaginates

51

receptor mediated transport

ligand binds receptor, cell engulfs