Chapter 3 - The Cell Flashcards
1
Q
Three theories
A
- Spontaneous Generation
- Cell Theory
- Endosymbiosis
2
Q
All living things (single and multi-cellular) are made of cells that share some common characteristics. What are those characteristics?
A
- Basic shape
- Internal content
- DNA chromosome(s), ribosomes, metabolic capabilities
3
Q
What are the two basic cell types?
A
Eukarotic and prokaryotic
4
Q
- Contain membrane-bound organelles that compartmentalize the cytoplasm and perform specific functions
- Contain double-membrane bound nucleus with DNA chromosomes
A
Eukaryotic cells
5
Q
No nucleus or other membrane-bound organelles
A
Prokaryotic cells
6
Q
What are the characteristics of life?
A
- Reproduction and heredity
- Growth and development
- Metabolism
- Movement and/or irritability
- Cell support, protection, and storage mechanisms
- Transport of nutrients and waste
7
Q
A solution that has the same solute concentration as another solution. There is no net movement or water particles, and the overall concentration on both sides of the cell membrane remains constant
A
Isotonic solution
8
Q
A solution that has a higher solute concentration than another solution. Water particles will move out of the cell, causing crenation
A
Hypertonic solution
9
Q
A solution that has a lower solute concentration than another solution. Water particles will move into the cell, causing the cell to expand and eventually lyse
A
Hypotonic solution
10
Q
In cells that lack a cell wall, changes in _______ pressure can lead to crenation in hypertonic environments or cell lysis in hypotonic environments
A
Osmotic
11
Q
Bacteria vary in shape, size, and arrangement but typically described by one of three basic shapes. What are those three?
A
- Coccus
- Bacillus
- Spirillum
12
Q
Arrangement of cells is dependent on pattern of ________ and how cells remain attached after division
A
Division
13
Q
- Singles
- Diplococci – in pairs
- Tetrads – groups of four
- Irregular clusters
- Chains
- Cubical packets (sarcina)
A
Cocci
14
Q
- Diplobacilli
- Chains
- Palisades
A
Bacilli
15
Q
What are the two major groups of appendages?
A
- Motility – flagella and axial filaments (periplasmic flagella)
- Attachment or channels – fimbriae and pili
16
Q
Surface coating
A
Glycocalyx
17
Q
What are the three parts of flagella?
A
- Filament
- Hook
- Basal body
18
Q
What are the flagellar arrangements?
A
- Monotrichous
- Lophotrichous
- Amphitrichous
- Peritrichous
19
Q
Guide bacteria in a direction in response to external stimulus
A
Flagellar responses
20
Q
Chemotaxis; positive and negative
A
Chemical stimuli
21
Q
Phototaxis
A
Light stimuli
22
Q
Signal sets flagella into rotary motion _________ or ________________
A
Clockwise or counterclockwise
23
Q
Results in smooth linear direction – run
A
Counterclockwise
24
Q
Tumbles
A
Clockwise
25
Internal flagella, enclosed in the space between the _____ ______ and the ____ ____ _____________
Outer sheath and the cell wall peptidoglycan
26
Periplasmic flagella produce cellular motility by contracting and imparting ________ or _______ motion
Twisting or flexing
27
Fine, proteinaceous, hairlike bristles emerging from the cell surface
Fimbriae
28
Function in adhesion to other cells and surfaces
Fimbriae
29
- Rigid tubular structure made of pilin protein
- Found only in gram-negative cells
- Function to join bacterial cells for partial DNA transfer called conjugation
Pili
30
Coating of molecules external to the cell wall, made of sugars and/or proteins
Glycocalyx
31
What are the two types of glycocalyx?
1. Slime laayer
| 2. Capsule
32
What are the functions of the glycocalyx?
- Protect cells from dehydration and nutrient loss
- Inhibit killing by white blood cells by phagocytosis, contributing to pathogenicity
- Attachment - formation of biofilms
33
External covering outside the cytoplasm
The cell envelope
34
The cell envelope is composed of what two basic layers?
Cell wall and cell membrane
35
Maintains cell integrity
The cell envelope
36
Determines cell shape, prevents lysis (bursting) or collapsing due to changing osmotic pressures
Cell wall
37
What is the primary component of the cell wall?
Peptidoglycan
38
Unique macromolecule composed of a repeating framework of long glycan chains cross-linked by short peptide fragments
Peptidoglycan
39
- Thick, homogeneous sheath of peptidoglycan
- 20-80 nm thick
- Includes teichoic acid and lipoteichoic acid: function in cell wall maintenance and enlargement during cell division; move cations across the cell envelope; stimulate a specific immune response
- Some cells have a periplasmic space, between the cell membrane and cell wall
Gram-positive cell wall
40
- Composed of an outer membrane and a thin peptidoglycan layer
- Outer membrane is similar to cell membrane bilayer structure
-Outermost layer contains
lipopolysaccharides and lipoproteins
(LPS)
- Lipid portion (endotoxin) may become
toxic when released during infections
- May function as receptors and
blocking immune response
- Contain porin proteins in upper layer
– regulate molecules entering and
leaving cell
- Bottom layer is a thin sheet of
peptidoglycan
- Periplasmic space above and below
peptidoglycan
Gram-negative cell wall
41
What are the two different groups of bacteria demonstrated by Gram stain?
1. Gram-positive bacteria
| 2. Gram-negative bacteria
42
Thick cell wall composed primarily of peptidoglycan and cell membrane
Gram-positive bacteria
43
Outer cell membrane, thin peptidoglycan layer, and cell membrane
Gram-negative bacteria
44
Differential stain that distinguishes cells with a gram-positive cell wall from those with a gram-negative cell wall
The Gram stain
45
Retain crystal violet and stain purple
Gram-positive
46
Lose crystal violet and stain red from safranin counterstain
Gram-negative
47
Important basis of bacterial classification and identification
The Gram stain
48
Practical aid in diagnosing infection and guiding drug treatment
The Gram stain
49
In ____________, the cell membrane surrounds the particle and pinches off to form an intracellular vacuole.
Phagocytosis
50
In ___________, the cell membrane surrounds a small volume of fluid and pinches off, forming a vesicle
Pinocytosis
51
In receptor-mediated ___________, the uptake of substances is targeted to a specific substance (a ligand) that binds at the receptor on the external cell membrane
Endocytosis
52
- Dense gelatinous solution of sugars, amino acids, and salts
- 70-80% water
- Serves as solvent for materials used in all cell functions
Cell cytoplasm
53
- Single, circular, double-stranded DNA molecule
- Aggregated in a dense area called the nucleoid
- DNA is tightly coiled
Bacterial Chromosome
54
- Small circular, double-stranded DNA
- Free or integrated into the chromosome
- Duplicated and passed on to offspring
- Not essential to bacterial growth and metabolism
- May encode antibiotic resistance, tolerance to toxic metals, enzymes, and toxins
- Used in genetic engineering
Plasmids
55
- Made of 60% ribosomal RNA and 40% protein
- Consist of two subunits
- Prokaryotic differ from eukaryotic ribosomes in size and number of proteins
- Site of protein synthesis
- Present in all cells
Ribosomes
56
- Intracellular storage bodies
- Vary in size, number, and content
- Bacterial cell can use them when environmental sources are depleted
- Examples: glycogen, poly b-hydroxybutyrate, gas vesicles for floating, sulfur and phosphate granules (metachromatic granules), particles of iron oxide
Inclusions and granules
57
Many bacteria possess an internal network of protein polymers that is closely associated with the cell wall. What is this called?
Cytoskeleton
58
Inert, resting, cells produced by some G+ genera
Endospores
59
What are some examples of gram positive endospores?
Clostridium, Bacillus, and Sporosarcina
60
What have a 2-phase life cycle?
- Vegetative cell
| - Endospore
61
- Resistance linked to high levels of calcium and dipicolinic acid
- Dehydrated, metabolically inactive
- Thick coat
- Longevity verges on immortality, 250 million years
- Resistant to ordinary cleaning methods and boiling
- Pressurized steam at 120oC for 20-30 minutes will destroy
Endospores
62
- Long, sheathed cylinder containing microtubules in a 9+2 arrangement
- Covered by an extension of the cell membrane
- 10X thicker than prokaryotic flagella
- Function in motility
Flagella
63
What are the locomotor appendages?
Flagella and cilia
64
- Similar in overall structure to flagella, but shorter and more numerous
- Found only on certain
protozoa and some animal cells
- Function in motility, feeding, and filtering
Cilia
65
- An outermost boundary that comes into direct contact with environment
- Usually composed of polysaccharides
- Appears as a network of fibers, a slime layer or a capsule
- Functions in adherence, protection, and signal reception
Glycocalyx
| external structure
66
Beneath the glycocalyx
- Fungi and most algae have a thick, rigid cell wall
| - Protozoa, a few algae, and all animal cells lack a cell wall and have only a membrane
67
Rigid, provides structural support and shape
Cell wall
68
Thick inner layer of polysaccharide fibers composed of chitin or cellulose and a thin layer of mixed glycans
Cell wall in fungi
69
varies in chemical composition; substances commonly found include cellulose, pectin, mannans, silicon dioxide, and calcium carbonate
Cell wall in algae
70
- Typical bilayer of phospholipids and proteins
- Sterols confer stability
- Serves as selectively permeable barrier in transport
Cytoplasmic (cell) membrane
71
Eukaryotic cells also contain membrane-bound organelles that account for _____ of their volume
60-80%
72
- Vesicles containing enzymes that originate from Golgi apparatus
- Involved in intracellular digestion of food particles and in protection against invading microbes
- Participate in digestion
Lysosomes
73
Membrane bound sacs containing particles to be digested, excreted, or stored
Vacuoles
74
Vacuole merged with a lysosome
Phagosome
75
More water outside the cell =
- Hypertonic environment
- Hypotonic cell
- Would move out of cell and cause cell to shrink/crenate
76
More water inside the cell =
- Hypotonic environment
- Hypertonic solution
- Would move into cell and cause cell to swell/lyse
77
Baceteria reproduces asexually through _______ ______
Binary fision
78
Bacterial reproduces sexually through ___________
Conjugation
79
Fimbriae are _______ than flagellla
Smaller
80
Capsule makes it more __________
Pathogenic
81
Capsule is _______ than slime layer
Thicker
82
Nearly all bacteria have a ____ ________
Cell envelope
83
Peptides are _______ molecules
Protein
84
What makes up the cell envelope of a Gram-positive bacteria?
- Cell wall
- Periplasmic space
- Cell membrane
85
What makes up the cell envelope of a Gram-negative bacteria?
- Cell membrane -------\\\\\\\\
- Periplasmic space ----- cell wall
- Cell wall -----------------/////////
- Periplasmic space
- Cell membrane
* Still just two layers
86
Mycolic acid makes the cell more _________
Pathogenic
87
Requires energy
| - Moves things against concentration gradient
Active transport
88
Bulk transoprt
Endocytosis
89
Dense area in cell
Nucleoid
90
Ribosomes are present in all _________ cells
Bacterial
91
Actin filaments are made of _____ _______
Actin protein
92
Centrioles take part in what?
Cell division
93
Contains chromosomes
Nucleus
94
Attached to nucleus
| - Continuous with the end of the ER
Nuclear envelope
95
Protein synthesis occurs where?
Rough ER
96
where does lipid synthesis occur?
Smooth ER
97
Ribososmes
Protein synthesis
98
Exiting cell
Exocytosis
99
Similar t cytoplasm
Stroma
