Topic #3 - Cell Structure Flashcards

1
Q

Cell Wall chemistry

A

Chemically Distinct - peptidoglycan is not anywhere else on planet

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

Periplasmic Space

A

Between Wall & Membrane

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

Cytoplasmic Membrane (or Plasma Membrane)

A

Selectively permeable membrane - moves stuff in & out. Contains lipids & proteins

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

Nucleoid Region

A

Localization of genetic material - no membrane

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

Cytoplasmic Membrane: Permeability Barrier

A

Selectively permeable - Active & Passive Transport

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

Cytoplasmic Membrane: Energy

A

Proton Motive Force: Charge gradient that creates energy (Also conservation)

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

Protein Anchors (Receptors)

A

Integrated or otherwise proteins - important for Transport, Chemotaxi & bioenergetics

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

Water Polarity

A

Positively charged hydrogen side = Ability for it to be a universal solvent (hydrophilic)

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

Hydrophilic

A

Water Loving - polar molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Hydrophobic

A

Water Fearing - Non-polar molecules

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

Amphipathic

A

Both polar & non-polar

Lipids in membranes

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

Lipid Amphipathicity

A

Fatty Acid=Hydrophobic

Glycerol phosphate=Hydrophilic

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

Cell membrane overview

A

6-8 nm thin
Lots of proteins
Unit Membrane

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

Integral Protein

A

Embedded all the way through membrane (transport). Hard to get rid of.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Peripheral proteins

A

Firmly assocated with membrane (usually stuck on integral membranes)

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

Unit Membrane

A

The phospholipid bilayer + Integral proteins. The whole kitten kaboodle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Fluid Mosaic Model

A

Proteins not fixed in space - mobile. (pieces of meat sliding on heating pan with no fixed position)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Hopanoids

A

Bacterial cholesterol - for mobility of proteins in unit membrane. Similar to cholesterol. Most abundant molecule on planet.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Bacteria/Eukarya: Membrane Lipids

A

Linkage of side chain & glycerol with Ester bond (organic acid group)

Fatty Acid Sidechain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Archaea: Membrane Lipids

A

Linkage of side chain & Glycerol with Ether bond (No org. acid group)

Hydrocarbon Side Chain (Isoprene)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Monolayer

A

Found only with tetraethers (super strong) in Archaean hyperthermophiles.

Contrasts with bilayer - no hydrophobicity in between 2 lipids - just one long lipid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Permeability: Simple Diffusion

A

Scarce - need small size & uncharged.

Oxygen, CO2 & water are biggest diffusers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why water diffuses

A

Flexible membrane & weak hydrophobic forces in the middle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Specific Transport Types

A

Active: Spends energy - against gradients
Passive: No energy - with gradients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Simple Transporters

A
  1. Uniporter
  2. Antiporter
  3. Symporter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Uniporters

A

No PMF used - Passive transport QED facilitated diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Antiporter

A

Use PMF - H+ & a substrate move in opposite directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Symporter

A

Use PMF - H+ & substrate move in same direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Proton Directionality in PMF

A

Outside of cell to Inside of cell ALWAYS in simple transport
Doesn’t depend on substrate
In to out: Makes PMF
Out to In: Uses PMF

30
Q

Group Translocation Overview

A

Substrate is chemically modified during transport through the membrane

31
Q

Glucose Phosphotransferase - Group Translocation Example

A

Yields energetic Phosphate from PEP

  1. Membrane spanning protein (2c or not 2c)
  2. P transfered to glucose during transport
  3. P makes transport directional & irreversible
32
Q

Glucose Phosphotransferase Production

A

PEP>ATP

Glucose-6-P is huge b/c Glycolysis is already started

33
Q

ATP Binding Cassette

A

ATP hydrolysis produces the energy in this transporter.

34
Q

ABC - Where

A

In periplasmic proteins (not integrated) binds substrate. Protein docks to membrane spanning complex

35
Q

ATP - How

A

ATP Hydrolysis process (on cassette) docked onto membrane-spanning complex

36
Q

Periplasmic Binding Proteins: Gram + vs. Gram-

A

G+: Periplasmic Binding Protein is free floating (Large periplasm)
G-: Periplasmic Binding Protein always docked

37
Q

Prokaryotes without cell walls

A

Mycoplasmas & Thermoplasma - Have outtermost part is the plasma membrane

38
Q

Osmotic Strength

A

Ability to take pressure of water - the cell wall does it like a car tire

39
Q

Hypotonic

A

Osmotic Strength of environment is less than in the cell

40
Q

Isotonic

A

Osmotic Strength inside & outside of cell are the same

41
Q

Hypertonic

A

Environment has much higher osmotic strength than inside cell. i.e. Saturated salt solutions

42
Q

Lysozyme

A

Degrades bacterial cell wall - a defense mechanism

43
Q

Lysozyme in Hypotonic solutions

A

Cell will burst - More H2O moves into cell than out.

44
Q

Penicillin Functionality

A

Interferes with cell wall synthesis. Stops D-Alanine bonds with DAP

45
Q

Plasmolysis

A

Occurs in hypertonic - Cell shrinks (water sucked out). Membrane pulls away from wall -> Larger periplasm. Cells can usually prevent this.

46
Q

Gram + Peptidoglycan

A

20-80 nm thick (big peptidoglycan)

47
Q

Gram- Peptidoglycan

A

2-7 nm thick (thin layer squashed between 2 membranes) to accompany the outer membrane (not plasma)

48
Q

Gram+ Periplasm

A

Located between wall & cytoplasmic membrane. Has proteins in exoenzymes.

49
Q

Gram- Periplasm

A

Is all the space between all the membranes. Can be quite large. Contains lots of proteins

50
Q

Peptidoglycan Makeup

A

2 Sugars (variable) + 4 amino acids. Change in sugars & how these 2 categories are linked

51
Q

NAG & NAM in Gram Negatives

A

“N-Acetyl” - acetate attached to amino group
Plus Glucose
Plus Amino group
Has Lysine

52
Q

Order of A.A. attachment in G-

A
  1. L-Alanine
  2. D-glutamic acid
  3. Lysine
  4. D-Alanine
53
Q

Order of A.A. attachment in G+

A
  1. L-Alanine
  2. D-glutamic acid
  3. DAP (Different)
  4. D-Alanine
54
Q

How Sugars & AA’s link

A
  1. Glycosyl linkages between NAG & NAM

2. Peptide cross links between D-Alanine & DAP of another

55
Q

Peptide Interbridge

A

Gram Positve only - links side chains of NAG & NAM. Flexibility.

56
Q

Cross-Linked polymer

A

Glycosyl & interbridges make a mesh.

57
Q

Gram + Cell Walls

A

Many layers of peptidoglycan

Teichoic acids

58
Q

Gram - Cell Walls

A
No Teichoic Acids
Few Peptidoglycan layers
Braun's Lipoprotein for connectivity
Porins
Lipopolysccharides
59
Q

Teichoic Acids

A
Perpendicular to peptidoglycan (sticks out)
Ribitol & glycerol - linked by P's
Often made of AA's/Sugar (D-Alanine)
Strength: Bonds to NAM
Negative Charge
60
Q

Lipoteichoic acids

A

Bound to membrane via a lipid

61
Q

Braun’s lipoprotein

A

Connects the peptidoglycan & outer membrane

62
Q

Porins

A

Pores of cells - diffuses larger molecules
Specific of general
3 tube structures w/4 pores (the Christmas Pretzel)

63
Q

Lipopolysaccharides

A
Most outer leaflet of outer membrane (G-)
Rough appearance
Endotoxin
Antigenic
1. Lipid A
2. Core polysaccharide
3. O-Specific polysaccharide (antigen)
64
Q

Endotoxin

A

Toxic component that is part of the cell (makes fevers happen)

65
Q

Lipid A

A

Part of outer leaflet of membrane-
Glucosamine & Fatty Acids
The actual endotoxin

66
Q

Core Polysaccharide

A

Constant for all species

67
Q

O-specific polysaccharide

A

Antigenic determinant
Variable at species level (EColi O157)
Variable to avoid immunity

68
Q

LPS Phosphates influence

A

Makes G- Cells negatively charged (dyeing important)

69
Q

Archaean Cell Walls

A

Lack outer membranes
Pseudopeptidoglycan
Polysaccharide Layers
S-Layer

70
Q

Pseudopeptidoglycan

A

NAM is replaced by other stuff
Glycosyl linkages resist Lysozyme-R
Amino Acids are different

71
Q

Polysaccharide Layers

A

Around archaean cells - not a capsule

72
Q

S-Layer

A

Lattice crystalline interlocking proteins/glycoproteins