Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PR - Big book > 13.1 > Flashcards

13.1 Flashcards

1
Q

Organelle summary - DRAW (p. 283)

A

RER - synthesis and modification of secretory, membrane-bound and organelle proteins

SER - DETOX, glycogen breakdown in liver, steroid synthesis in gonads (“the detox was smooth”), lipid manufacture/metabolism

Golgi - modification and sorting of proteins, some synthesis - the PACKAGER, also adds sugars to proteins (GLYCOSYLATION)

Peroxisome - metabolize lipids and toxins with hydrogen peroxide; contains enzyme called CATALASE which converts h2o2 to H2O + O2

Lysosomes - contains acid hydrolase (“lysing”) for digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

euchromatin

A

less dense than heterochromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

nucleolus

A

the ribosome factory

NO membrane surrounding it

consists of DNA, RNA pol, rRNA, protein components of ribosome

site of transcription of rRNA by RNA pol I

protein ribosome is transported into the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

nuclear localization sequence

A

larger proteins (>60 kDaltons) cannot freely enter the nucleus, they need a sequence of basic amino acids called a NLS - transported inside by specific transport mechanism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

mitochondria

A

single circular DNA molecule -> encodes rRNA, tRNA, and several proteins of the ETC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

all proteins start translation in the…? what is the signal sequence…?

A

ALL PROTEINS START translation in the cytoplasm

some proteins (secreted proteins, lysosomal proteins) have an amino acid sequence at their N-terminus called a SIGNAL SEQUENCE

the SS recognized by the signal recognition particle (SRP), which binds to the ribosome, forms a ribosome-SRP complex

ER has SRP receptors, the peptide is “pushed” into the ER lumen

after translation, the signal peptide is removed from the polypeptide by SIGNAL PEPTIDASE

for secreted proteins, the signal sequence is REMOVED

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

two sites of protein synthesis

A
  1. free ribosomes in cytoplasm
  2. ribosomes bound to rough ER

free ribosomes -> head to peroxisome, mitochondria, nucleus, or cytoplasm

rough ER -> secreted to extracellular environment, or plasma membrane, or membrane or interior of ER, GA, Lysosome (traffic’ed through VESICLES) => interior of ER, Golgi, lysosome, and extracellular environments are in a sense CONTIGUOUS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

integral membrane proteins have… TD

A

have hydrophobic amino acid residues called transmembrane domains – these DOMAINS are essentially signal sequences found in the interior of protein (NOT AT N-TERMINUS)

TDs are NOT REMOVED

TDs are threaded through the ER membrane during translation

portion of protein in the ER lumen faces the EXTERIOR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

ER additional functions

A
  1. post-translational modification of proteins (sometimes glycosylates)
  2. disulfide bond formation occurs in ER lumen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

default target for proteins of secretory path

A

PLASMA MEMBRANE

targeting signals are needed if a protein ends up elsewhere (GA, ER, lysosomes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

disulfide bonds occur in…

A

oxidative conditions

Golgi, ER, and extracellular are OXIDATIVE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

a protein produced in secretory pathway that needs to be sent to an organelle outside of the S-pathway needs…

A

…localization signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cellular Protein Traffic - DRAW (p. 290)

A

p. 290

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

GA - 3 purposes

A
  1. modification of proteins made in RER (especially oligosaccharide chains)
  2. Sorting and sending proteins (MAIL FACILITY)
  3. synthesis of macromolecules to be secreted
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

acid hydrolase

A

they only function in acidic environments - safety mechanism

a phagocytic vesicle fuses with lysosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

cell wall of bacteria, plants, and fungi

A
  1. bacteria -> peptidoglycan
  2. plants -> celluose
  3. fungi -> chitin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

colligative property

A

identity of particle is not important

  1. vapor-pressure depression
  2. boiling point elevation
  3. freezing-point depression - solute causes melting point to decrease
  4. osmotic pressure
18
Q

vapor pressure

A

adding more solute decreases vapor pressure (salt water)

boiling - atmospheric pressure = vapor pressure

19
Q

ion channels

A

involved in facilitated diffusion, down a EC gradient

20
Q

pores are found

A
  1. double nuclear membrane
  2. outer mitochondrial membrane
  3. Gram-(-) bacterial outer membrane
21
Q

Na/K ATPase

A

the driving force behind secondary active transport

  1. maintains osmotic balance between interior/exterior
  2. establish resting potential
  3. provide sodium concentration gradient used to drive secondary active transport
22
Q

secondary active transport

A

the transport process is not coupled directly to ATP hydrolysis; ATP is used to create a gradient, which is used to drive the transport of another molecule (coupling)

23
Q

chloride and calcium are…

A

preferentially extracellular

24
Q

clathrin

A

inside the cell involved in receptor-mediated endocytosis

25
Q

ligand and 3 types of signal transduction

A

ligand = key (“ligkey”), usually a hormone or neurotransmitter

the response = signal-transduction

  1. ligated-gated ion channels - an ion channel opens when binding a neurotransmitter
  2. catalytic receptors - enzymatic active site on the cytoplasmic side; enzyme activity initiated by ligand binding at the extracellular surface
  3. G-protein linked receptor - uses a secondary messenger to communicate with enzymes in the cytoplasm (cAMP is important, which AMPLIFIES the signal)
26
Q

G-protein epinephrine pathway (DRAW - p. 309)

A

…

27
Q

cytoskeleton (3 components)

A
  1. microtubules - thickest (25 nm)
  2. intermediate filaments (10 nm)
  3. microfilaments - thinnest (7 nm)

made of noncovalently polymerized proteins

example of QUATERNARY structure

28
Q

microtubule

A

hollow rod, alpha and beta-tubulin

ONLY 1 end can elongate

the other end is anchored to MICROTUBULE ORGANIZING CENTER (MTOC) – within MTOC is a pair of centrioles, which are organized into 9 microtubule triplets

aster - star-shaped, radiate out from the centrioles (Aster = MTOC). Fungi/plants do NOT have MTOC

polar fibers - connect chromosome to the aster

mitotic spindle - whole thing

Also: transport substances within the cell (railroad analogy) - driven by proteins that hydrolyze ATP and act as molecular motors

9+2 arrangement found in flagellum and cilia (9 pairs of MTs form a ring around two lone microtubules in the center). Prokaryotes have different structure.

29
Q

what connects microtubules?

A

each microtubule is bound to its neighbor by contractile protein called DYNEIN causes the movement of filaments past one another

30
Q

what attaches MTs to plasma membrane?

A

basal body (same structure as centriole)

31
Q

microfilaments

A

rods formed in cytoplasm from polymerization of globular protein ACTIN, which form a chain and wrap each other to form ACTIN FILAMENT

PINCHES the parent cell

AMOEBOID movement

32
Q

intermediate filaments

A

heterogenous, wide range of polypeptides

more permanent

provides strong cell structure

33
Q

tight junctions and desmosomes

A

epithelial cells in the gut

the seal is completed by desmosomes

desmosome -> hold cells together at concise points, not bands, composed of fibers that span the plasma membranes of two cells (anchored to plasma membrane by a plaque formed by protein keratin) - found at mechanically-stressed locations (bladder, cardiac)

34
Q

gap junctions

A

heart muscle cells

holes called gap junctions that allow ions to flow back and forth

35
Q

apical and basolateral

A

apical - facing the intestinal lumen

basolateral - facing the tissues

36
Q

gap junctions

A

pore-like connections between adjacent cells (cytoplasms can MIX ions, AAs, carbs, but not polypeptides or organelles)

allow membrane depolarization of action potential to pass from cell to cell

37
Q

prophase

A
  1. nucleolus disappears
  2. spindle and kinetochore fibers appear
  3. centriole pairs move to opposite ends
  4. nuclear envelope converts into tiny vesicles
38
Q

cleavage furrow

A

ring of actin filament that contracts

39
Q

Benzene

A

a mutagen, as is UV

40
Q

what kills a cell?

A

stressors include 1. nitric oxide, 2. toxin 3. cytokines

also, p53 -> apoptosis

41
Q

caspases

A

a type of protease, carries out apoptosis

cysteine in active site

cleave target proteins at aspartic acid sites (cleave-asp)

grouped into initiators and effectors

initiators - respond to extra- or intracellular death signals by clustering together and activating each other

activation of initiators leads to activation of effector caspase to trigger APOPTOSIS (see illustration p. 318)

PR - Big book (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions