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The Cell Flashcards

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1
Q

Cell theory

A

All living things are made of cells
All cells arise from preexisting cells.
Cells are the basic functional unit of life.
Cells carry DNA that is passed from parent to daughter cell

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2
Q

Prokaryotes

A

Single celled organisms. No nucleus, genetic material is in a single circular molecule located in the nucleoid region
Carry out the electron transport chain using the cell membrane

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3
Q

Eukaryotes

A

Unicellular or Multicellular organisms. Contains membrane bound nucleus. Reproduce via mitosis.

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4
Q

Organelles

A

Enclosed in semifluid cytosol, house working equipment within eukaryotic cells. Has own hydrophilic membrane that electrostatically interacts with the aqueous environment of the inner cell to regulate what enters the organelle.

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5
Q

Cytosol

A

Semifluid that allows for the diffusion of molecules throughout the cell.

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6
Q

Nucleus

A

Houses deoxyribonucleic acid (DNA), which is organized into chromosomes, which are organized by histones (linear DNA wraps around so it can be tightly packed). Enclosed by a double membrane envelope that has nuclear pores that allow genetic material to enter and leave.

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7
Q

Nucleolus

A

Housed inside the nucleus, and is location where ribosomal RNA is produced (ribosomes)(Takes up 25% of nucleus space and is seen as a dark spot inside nucleus)

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8
Q

Mitochondria

A

Contains an outer and inner membrane. Inner membrane is folded into cristae and contains enzymes for electron transport chain (used to make ATP). Intermembrane space holds mitochondrial matrix. Mitochondria divides independently from cell via binary fission and can trigger apoptosis by releasing mitochondrial enzymes into cytoplasm.

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9
Q

Lysosomes

A

Contain hydrolytic enzymes that can break down substances ingested by endocytosis as well as cellular waste. If these enzymes are released, the cell can experience autolysis.
Work in conjunction with Endosomes: which transport, package, and sort cell material travelling to and from the membrane

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10
Q

RER

A

Studded with ribosomes that allow the translation of proteins destined for secretion from cell

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11
Q

Endoplasmic Recticulum

A

Series of interconnected membranes and is continuous with the nuclear envelope of the nucleus.

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12
Q

SER

A

Used for lipid synthesis and detoxification. Transports proteins from RER to Golgi

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13
Q

Golgi apparatus

A

Consists of stacked membrane-bound sacs in which cellular products can be modified, packaged, and directed to specific cellular locations. Modifies cellular products by adding carbohydrates, phosphates, sulfates, or signal sequences

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14
Q

Peroxisomes

A

Contains hydrogen peroxide and can break down very long chain fatty acids via Beta-oxidation. Also participate in phospholipid synthesis and the pentose phosphate pathway.

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15
Q

Cytoskeleton

A

Provides stability and rigidity to the structure of the cell, while also allowing transportation pathways throughout the cell. Includes: Microfilaments, Microtubules, & Intermediate filaments.

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16
Q

Microfilaments

A

Made of actin. Provides structural protection for the cell and works with muscle contraction when paired with myosin. Also form cleavage furrow during cytokinesis of mitosis.

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17
Q

Microtubules

A

Composed of tubulin. Create pathways for motor proteins like kinesis and dynein to carry vesicles. Contribute to structure of cilia and flagella (9 pairs in a ring with 2 in the middle (9 + 2)).
Centrioles are found in centrosomes and are involved in microtubule organization in the mitotic spindle.

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18
Q

Intermediate filaments

A

Involved in cell-cell adhesion and maintenance of the integrity of the cytoskeleton. (Ex. keratin and desmin)

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19
Q

Epithelial tissues

A

Cover body & line its cavities in order to protect cells from invasion and desiccation. Absorb & secrete, also participates in sensation

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20
Q

Parenchyma

A

Functional part of the organ, made up of epithelial cells

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21
Q

Characteristics of epithelial cells

A

Polarized, with one side facing lumen or outside world and the other facing blood vessels or structural cells

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22
Q

Simple Epithelia

A

One layer of epithelial cells

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23
Q

Stratified epithelia

A

Many layers of epithelia cells

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24
Q

Pseudostratified epithelia

A

Appears to have multiple layers due to differences in cell heights, but actually have only one layer

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25
Epithelial shapes
Cuboidal : cube-shaped Columnar : long and narrow Squamous : flat and scale-like
26
Connective tissue
Supports body and provides framework for epithelial cells
27
Stroma
Formed by connective tissue to support organ structure by secreting materials to form an extracellular matrix. Includes: bone, cartilage, tendons, ligaments, adipose tissue, and blood
28
Domains of life
1. Archaea (prokaryotes) 2. Bacteria (prokaryotes) 3. Eukarya (eukaryotes)
29
Archaea
Often extremophiles and use chemical sources of energy (chemosynthesis). Similarities to Eukarya : start translation with methionine, similar RNA polymerases, has histones Similarities to Bacteria : single circular chromosome, divides by binary fission or budding
30
Bacteria
Similar in structure to eukaryotes, and can be both good and harmful to humans. Mutualistic symbiosis : both get something out of relationship Pathogenesis: bacteria harms human
31
Eukarya
Only non-prokaryotic domain
32
Bacteria shapes
Cocci : Spherical-shaped Bacilli : Rod-shaped Spirilli : Spiral-shaped
33
Obligate aerobes
Bacteria that requires oxygen for metabolism
34
Obligate anaerobes
Bacteria that cannot survive in oxygen-containing environments and can only carry out anaerobic metabolism
35
Facultative anaerobes
Bacteria that can survive in environments with or without oxygen and will toggle between metabolic processes based on environment.
36
Aerotolerant anaerobes
Bacteria that cannot use oxygen for metabolism, but can survive in an oxygen-containing environment
37
Cell envelope
Created by cell wall and cell membrane that controls the movement of solutes into and out of the cell
38
Gram-positive bacteria
Cell wall turns purple after crystal violet stain, followed by counterstain with safranin Has a thick cell wall composed of peptidoglycan and lipoteichoic acid
39
Gram-negative bacteria
Cell wall turns pink-red after crystal violet stain, followed by counterstain with safranin Has a thin cell wall composed of peptidoglycan and an outer membrane containing phospholipids and lipopolysaccharides
40
Characteristics of bacteria
May have on, two, or many flagella that generate movement of bacterium toward food or away from immune cells.
41
Chemotaxis
When bacteria move in response to chemical stimuli
42
Bacterial flagella structure
Flagella contains a filament composed of flagellin, a basal body that anchors and rotates the flagellum, and a hook that connects the two.
43
Prokaryotic ribosomes vs Eukaryotic ribosomes
Prokaryotic ribosomes are smaller (30S and 50S) vs Eukaryotic ribosomes (40S and 60S)
44
Binary fission
Prokaryotes multiply. Chromosomes replicates while the cell grows in size, until the cell wall begins to grow inward along the middle of cell, and eventually divides cell into two identical daughter cells
45
Plasmids
Extrachromosomal material in prokaryotes (beyond single circular chromosome) that can contain antibiotic resistance genes or virulence factors.
46
Episomes
Plasmids that can integrate into genomes of plasmids and therefore divide into daughter cells via binary fission
47
Transformation in bacteria
Type of genetic recombination that increases bacterial diversity. Occurs when genetic material from surroundings is taken up by the cell and incorporated into its genome
48
Conjugation in bacteria
Type of genetic recombination that increases bacterial diversity. Occurs when genetic material is transferred from one bacterium to another via a conjugation bridge Plasmid can be transferred from F+ to F- cell or from Hfr cell to a recipient
49
Types of bacterial recombination
1. Transformation 2. Conjugation 3. Transduction 4. Transposons
50
Transduction in bacteria
Type of bacterial recombination that allows for greater bacterial diversity. Occurs when genetic material is transferred from one bacterium to another via a bacteriophage vector
51
Transposons in bacteria
Type of bacterial recombination that allows for greater bacterial diversity. When genetic elements can insert into or remove themselves from genome
52
Bacterial growth pattern
1. Lag phase : bacteria adapt to new local conditions 2. Exponential (log) phase : growth increases exponentially 3. Stationary phase : surrounding resources are reduced, growth levels plateau 4. Death phase : surrounding resources are depleted
53
Capsid
Protein coat that surrounds viruses
54
Virus structure
Contain genetic material, a protein coat (capsid), and sometimes a lipid-containing envelope
55
Characteristics of viruses
1. They are obligate intracellular parasites : cannot survive and replicate without a host cell. 2. Individual virus particles are called virions 3. Infect cells by attaching to specific receptors and can fuse with membrane or be brought in via endocytosis, or can inject genome into cell 4. Reproduces by replicating and translating genetic material using host cell's ribosomes, tRNA, amino acids, and enzymes
56
Bacteriophages
Viruses that target bacteria
57
Characteristics of bacteriophages
Tail sheath : injects the genetic material into bacterium | Tail fibers: allows the bacteriophage to attach to the host cell
58
Characteristics of viral genomes
1. Can be composed of DNA or RNA that can be single- or double-stranded 2. Single-stranded RNA viruses may be positive sense (translated by the host cell) or negative sense (requires a complementary strand to be synthesized by RNA replicase before translation (in nucleus of host cell or brought in by virus))
59
Retroviruses
Contain single-stranded RNA, from which a complementary DNA strand is made using reverse transcriptase. The DNA strand can then be integrated into the genome--MORE INFO HERE
60
Extrusion
Viral progeny are released via cell death, lysis, or extrusion (virus leaves host cell without killing it)
61
Lytic cycle
Type of life cycle for a bacteriophage. Bacteriophage produces massive number of new virions until cell lyses. Bacteria in this phase are considered virulent.
62
Lysogenic cycle
Type of life cycle for a bacteriophage. Virus integrates into the host genome as a pro-virus or prophage, which can then reproduce along with the cell. The provirus can remain in the genome indefinitely, or may leave the genome in response to a stimulus and enter the lytic cycle.
63
Prions
Infectious proteins that trigger misfolding of other proteins, usually converting an alpha helix into a beta-pleated sheet. This decreases the solubility of the protein and increases its resistance to degradation
64
Viroids
Plat pathogens that are small circle of complementary RNA that can turn off genes, resulting in metabolic and structural changes and, potentially, cell death
65
Cytoplasmic/Extranuclear inheritance
Transmission of genetic material independent of the nucleus (mitochondria)

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