Bacterial Cell Structure Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Phospholipids are composed of

A

A polar head (glycerol and phosphate group)
2 fatty acid tails (Non-polar)

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

The purpose of phospholipids

A

Make up the lipid bilayer which is the major lipid component of the membrane

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

Hapanoids

A

Maintains membrane homeoviscosity in bacteria

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

Facilitated diffusion

A

Spontaneous passive transport pf molecules or ions across a membrane with specific integral proteins

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

Active transport

A

Movement of ions or molecules across a cell membrane into a region of higher concentration with the assistance of enzymes requiring energy

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

Respiration (Electron Transport System): proton gradients

A

The energy-released pumps released pumps hydrogen out of matrix space. The gradient created by this drives hydrogen back through the membrane, through ATP synthase. As this happens, the enzymatic activity of ATP synthase synthesizes ATP from ADP

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

Photosynthesis

A

Light goes through the ETC to split water as a source of electrons to produce oxygen

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

Ion gradients as driving force for co-transport

A

When driving ions and molecules pair up and move in the same direction

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

Environmental sensing and signal transduction

A

The process by which a cell responds to substances molecule move in outside the cell through signaling molecules found in the surface and inside the cell

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

Cytoplasm

A

Water, Macromolecules (proteins, DNA, RNA), Molecular building blocks and metabolites (AA, nuclei acids, sugars), Inorganic ions (K+,Na+, Cl-)

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

Nucleoid

A

Biggest structure in a cell and holds all the genetic information in a bacterial cell

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

How do cations (Mg^2+, K+, Na+) help tightly pack DNA?

A

They associate with the phosphate groups to neutralize the charge

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

How do small positive charged proteins help to tightly pack DNA?

A

They act as scaffolding for the bacteria to wrap around which also neutralizes the charge

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

How do topoisomerases help tightly pack DNA?

A

They preform supercoiling

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

Is the nucleoid an organell?

A

Not membrane-bound so no

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

Polyhydroxybutyrate

A

Used for carbon storage

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

Cyanophycin

A

Used for nitrogen storage

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

Volutin

A

Used for phosphorus storage

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

Where are sulfur globules observed?

A

Thiomargarita namibiensis

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

What do sulfur globules consist of?

A

Elemental sulfur

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

Gas vesicles

A

Provide buoyancy to the cells allowing the cells to regulate their position in a water column in response to light or nutrient levels

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

Carboxysomes

A

Contains RuBisCO which is involved in the conversion of inorganic carbon into organic matter during photosynthesis

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

O2 competes with CO2 for RuBisCO

A

Ensures an oxygen-free environment for carbon fixation

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

O2 fixation produces 2-phosphoglycolate

A

Inhibits some of the other enzymes involved in photosynthesis: accumulation is toxic

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

Is Carboxysome protein encased?

A

Yes they are likely a precursor to the organelles in eukaryotes

26
Q

Are magnetosomes organelles?

A

Yes which is rare in bacterial cells

27
Q

What do magnetosomes do?

A

Cause cells to align with magnetic fields and is believed to allow these bacteria to navigate with respect to Earth’s magnetic field

28
Q

Bacterial cell wall

A

Protects bacterial cell from changes in osmotic pressure and mechanical/sheer forces and give bacterial their shape

29
Q

What is the structure of the bacterial cell wall?

A

A NAM (N-Acetylmuramic acid) and a NAG (N-Acetylglucosamine) bonded wth an peptide chain attached to the NAM subunit

30
Q

What is a Monodermic cell?

A

A one-cell membrane with a thick peptidoglycan external layer to cell membrane

31
Q

What color does a Monodermic cell stain in gram staining?

A

Purple/violet because it is gram-positive

32
Q

What are some distinguishing characteristics of monodermic cells?

A

teichoic acid and lipoteichoic acid (adds strength and rigidity to the cell wall)

33
Q

What is a Didermic cell?

A

two cell membranes (inner and outer) with a thin peptidoglycan layer positioned in the periplasmic space (between the two membranes)

34
Q

What color are Didermic cells when they are gram stained?

A

Pink because they are gram-negative

35
Q

What distinguishing characteristics are there for Didermic cells?

A

Lipopolysaccharides on the outer layer of the outer membrane

36
Q

Why do Didermic cells have two phospholipid bilayers?

A

Shields peptidoglycan from hist immune system and from lysozyme

37
Q

Filament

A

Extends outward from the cell in a helical structure

38
Q

What is the purpose of the filament in the Flagella

A

Acts like a screw propeller

39
Q

Hook

A

A curved adaptor that is comprised of FlgE

40
Q

What is the purpose of a hook on a flagellum?

A

Forms the transition from the basal body to the filament

41
Q

Basal body

A

Constructed as a series of disks stacked on top of eachother

42
Q

What is the purpose of the basal body in the flagellum?

A

Anchors the flagella in the cell envelope and interfaces with the motor that drives rotation

43
Q

Motor

A

in the plasma membrane and looks like a thread spool for the bottom

44
Q

What is the purpose of the motor in the flagellum?

A

Converts energy from the proton motive force to drive rotation of the filaments

45
Q

Monotrichous

A

Single flagella at one end

46
Q

trichous

A

hair

47
Q

Lophotrichous

A

Multiple flagella located at one or both ends

48
Q

lopho

A

tuft/crested

49
Q

Peritrichous

A

multiple flagella spread all over the surface of the cell

50
Q

Internal flagella

A

keep the flagellar filament shielded inside the periplasm (spirochetes)

51
Q

Bacterial specialized external structure

A

Pilus/fimbria

52
Q

Composition of Pilus/fimbria

A

Pilin protein subunits

53
Q

What is the primary role of pilus/fimbriae?

A

Adhesion

54
Q

What is the secondary role of pilus/fimbria?

A

Movement: twitching motility and conjugation

55
Q

What are capsules composed of?

A

Polysaccharides

56
Q

What are the roles of capsules?

A

A shield from the immune system
Retain water to prevent desiccation
Adherence to surfaces: Biofilms

57
Q

What are surface arrays (S layers)?

A

A regular, crystalline-like layer of protein that serves as a suit of armor

58
Q

Where are S-layers found?

A

Many bacteria (both G+, G- and archeons)

59
Q

What do S-layers protect the cell from?

A

Infection by bacteriophages
Blocking penetration by predatory bacteria
Shielding the cell from attack by a host’s immune system

60
Q

What are S-layers made of?

A

acidic and hydrophobic amino acids (some covalently attached to sugars)

61
Q

Where are S-layers located?

A

Anchored to the outer layer of a cell (peptidoglycan in G+, lipopolysaccharides in G-, plasma membrane in acheons that lack a rigid cell wall)