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Flashcards in Cells Deck (51)
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1
Q

3 membrane protein types

A
  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
Q

function of membrane proteins - 8

A
  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
Q

cholesterol

A

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

4
Q

glycocalyx

A

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
Q

nucleus

A

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
Q

nuclear lamina

A

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

7
Q

nucleoid

A

irregular shaped region of prokaryote that contains genetic material

8
Q

cytoplasm

A

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

9
Q

cytosol

A

the gel, not the stuff suspended in it

10
Q

ribosomes

A

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

11
Q

ER, rough

A

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

12
Q

ER, smooth

A

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

13
Q

lysosome

A

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

14
Q

golgi

A

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

15
Q

peroxisomes

A

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

16
Q

glyoxysomes

A

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

17
Q

microtubules (MT)

A

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
Q

intermediate filaments

A

support, maintain shape

19
Q

microfilament (MF)

A

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

20
Q

MTOC

A

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
Q

transport vacuole

A

move materials between organelles

22
Q

food vaculole

A

temporary food storage, merge with lysosome to break down

23
Q

tonoplast

A

membrane of central vacuole

24
Q

central vacuole

A

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

25
Q

storage vacuole

A

starch, pigments, toxic substances (nicotine)

26
Q

contractile vacuoles

A

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
Q

cell walls

A

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

28
Q

ECM

A

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
Q

plastids

A

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
Q

carotenoids

A

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
Q

mitochondria

A

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
Q

beta oxidation

A

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
Q

cytoskeleton

A

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

34
Q

plant in hypotonic soln
isotonic
hypertonic

A

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
Q

endomembrane system *what does it not include!

A
  • 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
Q

brownian movement

A

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
Q

cyclosis/streaming

A

circular motion of cytoplasm around cell transport molecules

38
Q

intracellular circulation, 3 components

A
  1. brownian movement
  2. cyclosis/streaming
  3. ER - provides channel through cytoplasm, PM–>nuc membrane
39
Q

extracellular circulation

A

diffusion & circulatory system

40
Q

anchoring junctions

A

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
Q

tight junctions

A

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
Q

gap junction

A

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

43
Q

plasmodesmata

A

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

44
Q

prokaryote, 5 traits

A

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

45
Q

bulk flow

A

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

46
Q

plasmolysis

A

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

47
Q

dialysis

A

diffusion of different solutes across selectively permeable membranes

48
Q

countercurrent exhcange

A

diffusion by bulk flow in opposite directions

49
Q

phagocytosis

A

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

50
Q

pinocytosis

A

active transport of undissolved liquid; PM invaginates

51
Q

receptor mediated transport

A

ligand binds receptor, cell engulfs