Biology Ch. 1: The Cell Flashcards
(159 cards)
1
Q
Num cells in body
A
37 trillion
2
Q
Ratio of bacterial to eukaryotic cells
A
10 to 1
3
Q
Cell Theory
A
- All living things are composed of cells
- The cell is the basic functional unit of life
- Cells arise only from preexisting cells
- Cells carry genetic information in the form of DNA, which is passed from parent to daughter cell
4
Q
Viruses and cell theory
A
No alive because can only replicate by invading other organisms and genetic material is RNA
5
Q
Eukaryotic reproduction
A
Mitosis - two identical daughter cells
6
Q
Cytosol
A
Semifluid within cell, allows for diffusion of molecules throughout cell, suspends organelles
7
Q
Membranes of eukaryotic cells
A
Both cell membrane and organelle membranes contain phospholipids with hydrophilic interior and exterior and hydrophobic core
8
Q
Eukaryotic cells
A
Have membrane bound organelles, a nucleus, and may form multi-cellular organisms
9
Q
Nucleus
A
Contains DNA organized into chromosomes, surrounded by nuclear membrane/envelope
10
Q
Chromosomes
A
Linear strands of DNA already wound around histones
11
Q
Nuclear membrane/envelope
A
Double membrane that contains nuclear pores for two-way exchange or materials between nucleus and cytosol
12
Q
DNA
A
Genetic information, coding regions called genes, linear DNA would around histones then wound into chromosomes
13
Q
Genes
A
Coding regions of DNA
14
Q
Nucleolus
A
Subsection of the nucleus in which ribosomal RNA is synthesized, 25% of nucleus volume, darker spot
15
Q
Mitochondria
A
Power plant of the cells, has inner and outer membrane, can divide independently from nucleus with binary fission, can trigger apoptosis by releasing enzymes into cytoplasm
16
Q
Outer mitochondrial membrane
A
Forms barrier with cytosol
17
Q
Inner mitochondrial membrane
A
Folded into cristae, contains molecules and enzymes for ETC, contains mitochondrial matrix
18
Q
Mitochondria intermembrane space
A
Space between inner and outer mitochondrial membranes
19
Q
Lysosomes
A
Single membraned and contain hydrolytic enzymes that can break down substances ingested by endocytosis and cellular waste products. When enzymes released, autolysis can occur
20
Q
Endoplasmic reticulum
A
Series of interconnected membranes, continuous with nuclear envelope
21
Q
Rough ER
A
Studded with ribosomes
22
Q
Ribosomes
A
Permit translation of proteins destined for secretion
23
Q
Smooth ER
A
Used for lipid synthesis and detoxification, also transports proteins from the RER to Golgi apparatus
24
Q
Golgi apparatus
A
Consists of stacked membrane-bound sacs in which cellular products can be modified, packaged, and directed to specific cellular locations
25
Peroxisomes
Contain hydrogen peroxide and can break down long chain fatty acids via beta-oxidation. Also participate in phospholipid synthesis and the pentose phosphate pathway
26
Cytoskeleton
Provides stability and rigidity to the overall cell, which also providing transport pathways for molecules within the cell
27
Microfilaments
Composed of solid polymerized actin, provide structural protection for the cell (to both compression and fracture) and can cause muscle contraction through interactions with myosin. Also help form the cleavage furrow during cytokinesis in mitosis
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Actin
Forms microfilaments
29
Microtubules
Composed of hollow polymers of tubulin, create pathways for motor proteins (kinesin and dynein) to carry vesicles, contribute to structure of cilia and flagella where they are organized in a 9 +2 structure, attach centrioles and chromosomes during mitosis to help pull sister chromatids apart
30
Tubulin
Forms microtubules
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Kinesin and dynein
Motor proteins whose travel is aided by microtubules
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Cilia
Projections from a cell that are involved in the movement of materials along the surface of the cell, structure supported by microtubules in 9+2 pattern
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9+2 structure
Nine pairs of microtubules in a ring with two microtubules in the center, cilia and flagella structure
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Centrioles
Found in centromeres and are involved in microtubule organization in the mitotic spindle - 9 triplets of microtubules with hollow center
35
Intermediate filaments
Involved in cell-cell adhesion and maintenance of the integrity of the cytoskeleton by increasing rigidity and anchoring organelles (can withstand a ton of tension)
36
Examples of intermediate filaments
Keratin and desmin
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Epithelial tissues
Covers the body and lines its cavities, protects against pathogen invasion and desiccation, some involved in absorption, secretion, and sensation
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Parenchyma
Functional parts of the organ, typically formed by epithelial cells
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Epithelial cells polarization
Can be polarized with one side facing human or outside world and other facing blood vessels or structural cells
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Simple epithelia
One layer epithelial cells
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Stratified epithelia
Many layered epithelial cells
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Puesdostratified epithelia
Appear to have multiple layers due to differences in cell heights but are actually only one layer
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Epithelia layer classifications
Simple, stratified, puesdostratified
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Epithelia shape classifications
Cuboidal, columnar, and squamous
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Cuboidal cells
Cube shaped
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Columnar cells
Long and narrow
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Squamous cells
Flat and scalelike
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Connective tissue
Supports the body and provides framework for epithelial cells, forms stroma in most organs by secreting materials (collagen and elastin) to form extracellular matrix
49
Stroma
Support structure generally formed by connective tissues
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Connective tissues examples
Bone, cartilage, tendons, ligaments, adipose tissue, and blood
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Histones
Organizing proteins that linear DNA is wound around
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Cristae
Infoldings in inner mitochondrial membrane, increase SA for ETC
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Mitochondrial matrix
Space inside inner mitochondrial matrix, contain protons will be pumped to intermembrane space and then will flow through ATP synthase to generate ATP during oxidative phosphorylation
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Cytoplasmic or extranuclear inheritance
Transmission of genetic material independent of the nucleus
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Apoptosis
Programmed cell death
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Endosomes
Transport, package, and sort cell material traveling to and from the membrane - can transport to the trans golgi, the cell membrane, or the lysosomal pathway for degradation
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Autolysis
When lysosomes release enzymes and apoptosis occurs via cellular component degradation
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Exocytosis
Secretion where a secretory vesicle merges with the cell membrane and its contents are released
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Golgi apparatus product modification
Addition of groups, addition of signal sequences to direct delivery of the product
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Three components of cytoskeleton
Mircofilaments, microtubules, and intermediate filaments
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Cytokinesis
Division of materials between daughter cells
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Flagella
Involved in movement of the cell itself, structure supported by microtubules in 9+2 pattern
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Kinetochores
Complexes that attach microtubules to chromosomes to help pull sister chromatids apart
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Tissue types
Epithelial, connective, muscle, and nervous
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Basement membrane
Layer of connective tissue keeping epithelial cells together
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Lumen
Hollow inside of an organ or tube
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Prokaryotes
Do not contain membrane-bound organelles, contain genetic material in single circular molecule of DNA located in the nucleoid region
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Nucleoid region
Region where single circular molecule of DNA is location in prokaryotes
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Three domains of life
Archaea, bacteria, eukarya
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Archaea
Often extremophiles, live in harsh environment (temp, salinity, no light), use chemical sources for energy (chemosynthesis); have similarities to both eukaryotes and bacteria
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Archaea similarities to eukaryotes
Start translation with methionine, similar RNA polymerases, histones
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Archaea similarities to bacteria
Single circular chromosome, divide by binary fission or budding
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Bacteria
Similar structure to eukaryotes, complex relationships with humans including mutualistic symbiosis and pathogenesis
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Mutualistic symbiosis
Both organisms benefit from the relationship
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Pathogenesis
Harm is caused to one organism in the relationship
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Eukarya
Only non-prokaryotic domain
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Bacteria shape classifications
Cocci, bacilli, spirilli
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Cocci
Spherical bacteria
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Bacilli
Rod-shaped bacteria
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Spirilli
Spiral-shaped bacteria
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Bacterial metabolic classifications
Obligate aerobes, obligate anaerobes, facultative anaerobes, aerotolerant anaerobes
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Obligate aerobes
Require oxygen for metabolism
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Obligate anaerobes
Cannot survive in oxygen-containing environments and only carry out anaerobic metabolism
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Facultative anaerobes
Can survive in environments with or without oxygen and will toggle between metabolic processes based on the environment
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Aerotolerant anaerobes
Cannot use oxygen for metabolism, but can survive in an oxygen-containing environment
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Cell envelope
Made of cell wall and cell membrane, contain movement of solutes into and out of cell to maintain concentration gradient
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Gram staining
Bacteria cell wall classification done with a crystal violet stain followed by a counterstain with safranin
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Gram positive
Bacteria that turn purple during gram staining; thick cell wall composed of peptidoglycan and lipoteichoic acid
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Gram negative
Bacteria that turn pink-red following gram staining; thing cell wall composed of peptidoglycan and an outer membrane containing phospholipids and lipopolysaccharides
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Bacteria movement
Possibly have one, two, or many flagella to move bacterium towards food or away from immune cells
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Chemotaxis
Chemical stimulus that causes movement response in bacteria
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Bacteria flagella
Contains a filament, a basal body, and a hook
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Prokayotes ETC
Uses cell membrane
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Prokaryotic ribosomes
Smaller than eukaryotic ribosomes
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Eukaryotic ribosomes size
40S and 60S
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Prokaryotic ribosome size
30S and 50S
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Binary fission
Prokaryotes division where chromosomes replicate while the cell grows in size, until the cell wall begins to grow inward along the midline of the cell and divides it into two identical daughter cells, faster than mitosis
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Plasmids
Carries extrachromosomal material in prokaryotes, may contain antibiotic resistance or virulence factors, some are episomes, not considered in genome because not necessary for survival
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Episomes
Plasmids that can integrate into the genome
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Virulence factors
Traits that increase pathogenicity, such as toxin production, projections that allow attachment to certain kinds of cells, or features that allow evasion of the host's immune system
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Bacterial genetic recombination
Increases bacterial diversity, includes transformation, conjugation, and transduction
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Transformation
Occurs when genetic material from the surroundings is taken up by a cell, which can incorporate this material into its genome
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Conjugation
Transfer of genetic material from one bacterium to another across a conjugation bridge, form of mating (sexual reproduction), unidirectional from donor male+ (must have sex factor plasmid) to recipient female-, can allow for rapid passing of plasmids
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Conjugation bridge
Facilitates transfer of genetic information, made of sex pili
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Fertility factor conjugation
Fertility plasmid is transferred from F+ cells to F- cells, making them F+cells, can allow for rapid passing of plasmids (ex. antibiotic resistance) because more cells can share plasmids with others
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Hfr cells conjugation
When a donor cells with a sex factor attempts to transfer its entire genome into a recipient, but only a a portion of the genome can be transferred before the bridge breaks. hfr - high frequency of recombination
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Transduction
Transfer of genetic material form one bacterium to another via a bacteriophage vector
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Transposons
Genetic elements that can insert into or remove themselves from the genomee
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Bacterial growth phases
Lag phase, exponential (log) phase, stationary phase, death phase
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Lag phase
Bacteria adapts to new local conditions
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Exponential (log) phase
Growth increases exponentially
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Stationary phase
Resources are reduced, growth levels off
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Death phase
Resources are depleted, so bacteria die
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Virus makeup
Genetic material, a capsid, and sometimes a lipid-containing envelope
115
Viruses
Obligate intracellular parasites, cannot survive and replicate out of a hose cell
116
Virions
Individual virus particles/progeny
117
Capsid
Protein coat of viruses
118
Host cell
Cell that virus uses to replicate and reproduce
119
Bacteriophages
Viruses that target bacteria (do not actually enter, just inject genetic material), contain a tail sheath and tail fibers
120
Tail sheath
Injects genetic material into a bacterium
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Tail fibers
Allows bacteriophage to attach to the host cell
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Viral genomes
May be composed of DNA or RNA, could be single or double stranded or circular
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Single stranded RNA viruses
May be positive sense or negative sense
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Positive sense
Single stranded RNA virus that can be translated by host cell
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Negative sense
Single stranded RNA that requires a complementary stand to be synthesized by RNA replicase before translation
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RNA replicase
-
127
Retroviruses
Enveloped and contain a single-stranded RNA genome which can create a complementary DNA stand using reverse transcriptase, DNA strand can then be injected into the genome
128
Reverse transcriptase
Can synthesize DNA from single stranded RNA
129
Virus cell infection
Attach to SPECIFIC receptors, can enter the cell by fusing with plasma membrane, endocytosis, or injecting genome into cell
130
Virus reproduction
Replicates and translates genetic material using the host cell's ribosomes, tRNA, amino acids, and enzymes
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Viral progeny release
Can be released via cell death, lysis, or extrusion
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Extrusion
A virus leaving a cell by fusing with its plasma membrane
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Bacteriophage life cycles
Lytic and lysogenic cycle
134
Lytic cycle
Bacteriophage products massive numbers of new virions until the cell lyses, viruses termed virulent
135
Virulent
Viruses who are in the lytic phase
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Lysogenic cycle
Virus integrates into the host genome as a provirus or prophage, reproduces along with the cell, can remain in the genome indefinitely or may leave the genome in response to a stimulus and enter the lytic cycle, can potentially take other bacteria genes with them which leads to transduction
137
Prions
Infectious proteins that trigger misfiling of other proteins, usually converting alpha helical structures to beta pleated sheets, decreases the solubility of a protein and increases its resistance to degradation which interferes with cell function
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Viroid
Plant pathogens that are small circles of complementary RNA that can turn off genes, resulting in metabolic and structural changes, and potentially cell death
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Chemosynthesis
Energy generation by some Achaea that uses organic compounds including sulfur and nitrogen based compounds such as ammonia
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Fimbriae
Similar to cilia, some bacteria have them
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Pathogens/parasites
Bacteria that provide no advantage or benefit to the host and cause disease
142
Prokaryote cellularity
Single-celled organisms so they must perform all functions required for life and must protect themselves from the environment - however, some prokaryotes live in colonies where they can communicate with each other
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Cell wall
Forms outer barrier of the cell, provides structure and controls movement of solutes - present in prokaryotes
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Bacteria cell membrane
aka plamsa membrane - similar to eukaryote in that it Is made of phospholipids
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Peptidoglycan
Polymeric substance made from amino acids and sugars, provides structure and protection from hosts immune system to bacteria - found in both gram positive and gram negative cells but a lot more in gram positive
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Lipoteichoic acid
Found in gram positive cell walls, function unclear, may active human immune response
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Periplasmic space
Space between inner and outer cell membrane
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Lipopolysaccharides
Trigger immune response in gram-negative bacteria which is much stronger than the response to lipoteichoic acid in gram-positive bacteria
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Flagella filament
Hollow, helical structure composed of flagellin
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Flagella Basal body
Complex structure that anchors flagellum to cytoplasmic membrane and is motor (rotates up to 300 Hz)
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Flagella Hook
Connects the filament and basal body
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Sex pili
Appendages on a donor male bacteria that create conjugation bridge, bacteria must have plasmid with sex factor to do this
153
Sex factors
Plasmids that hold necessary genes to create piles and thus conjugation bridge, can be integrated into host genome with transformation
154
Vector
A virus that carries genetic material from one bacterium to another
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Virus envelope
Could be composed of phospholipids and virus-speciic proteins, sensitive to heat, detergents, and desiccation (easier to kill)
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Virus replication DNA
Typically must enter nucleus to be transcribed, retroviruses also travel to nucleus to be integrated into genome
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Virus replication positive sense RNA
Stays in cytoplasm and is directly translated into proteins by host cell ribosomes
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Virus replication negative sense RNA
Requires synthesis of complementary strand of RNA via RNA replicase then can be translated into proteins
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Superinfection
Simultaneous infection of a cell, not common because infection with one strain of phage makes the bacterium less susceptible
