Bio- Ch 1 Flashcards
(91 cards)
1
Q
Cell theory
A
- All living things are composed of cells
- Cell is basic functional unit of life
- Cells arise only from preexisting cells
- Cells carry genetic information through DNA and it passes from parent to daughter cell
2
Q
Viruses
A
Unable to reproduce on their own
:. Not considered living organisms
3
Q
Eukaryotic cells
A
Contain a true nucleus (enclosed with membrane)
-can be uni/multicellular
4
Q
Cell membranes
A
Contain phospholipids
-hydrophilic ends and hydrophobic core
5
Q
Cytosol
A
Suspends organelles
-allows diffusion of molecules throughout cell
6
Q
Nucleus
A
- Contains DNA organized into chromosomes
- chromosomes have coding regions called genes
7
Q
Nuclear membrane
A
Double membrane with nuclear pores
8
Q
Nuclear pores
A
Allow for 2-way exchange of material between nucleus and cytosol
9
Q
Nucleolus
A
Subsection of nucleus
-where rRNA is synthesized
10
Q
Mitochondria
A
- outer and inner membrane
- can divide independently of nucleus via binary fission
- trigger apoptosis by releasing mitochondrial enzymes into cytoplasm
11
Q
Outer membrane (mitochondria)
A
Barrier between cytosol and mitochondria
12
Q
Inner membrane (mitochondria)
A
Folded into Cristae
-contains enzymes for electron transport chain
13
Q
Inter-membrane space
A
Between inner and outer membrane
14
Q
Mitochondrial matrix
A
Inside the inner membrane
15
Q
Apoptosis
A
Programmed Cell death
16
Q
Lysosomes
A
- have hydrolytic enzymes that break down substances ingested by endocytosis and cellular waste products
- of enzymes are released, leads to autolysis
17
Q
Endoplasmic reticulum (ER)
A
- series of interconnected membranes
- continuous with nuclear membrane
18
Q
Rough ER
A
Studded with ribosomes
-permit translation of proteins
19
Q
Smooth ER
A
Used for lipid synthesis and detoxification
20
Q
Golgi apparatus
A
-consists of stacked membrane bound sacs where cellular products = modified, packages and directed to specific cellular locations
21
Q
Peroxisomes
A
- contain H2O2 (hydrogen peroxide)
- can break down long chain fatty acids via Beta Oxidation
- participate in phospholipid synthesis and pentose phosphate pathway
22
Q
Cytoskeleton
A
Provides stability and rigidity
-provides transport pathways for molecules within the cell
23
Q
Types of cytoskeleton
Microfilaments
A
Composed of actin
- provides structural protection from cell
- cause muscle contraction through interactions with myosin
- helps with cleavage furrow during cytokinesis
24
Q
Types of cytoskeleton
Microtubules
A
- composed of tubulin
- create pathways for proteins–like Kinesin and Dynein–to carry vesicles
- contribute to structure of Flagella and Cilia
25
Cilia and flagella organization
Nine pairs of microtubules in a ring with two microtubules in center (9 + 2 structure)
26
Centrioles
- found in centrosomes
- involved in microtubule organization in mitotic spindle
- nine triplet microtubules with hollow center
27
Types of cytoskeleton
| Intermediate filaments
Involved in cell-cell adhesion
- maintenance of integrity of cytoskeleton
- anchor organelles
- examples: keratin, Desmin
28
Epithelial tissues
- covers the body
- lines cavities
- protection against pathogen invasion and desiccation
- some absorb and secrete substances or participate in sensation
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Parenchyma
Formed from epithelial cells
| -functional parts of organ
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Epithelial cells = polarized
One side faces lumen (outside world) and another faces blood vessels and structural cells
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Simple epithelia
Have one layer
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Stratified epithelia
Have many layers
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Psuedostratified epithelia
Appear to have multiple layers-Bc of differences in cell heights- but actually have only one
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Cubodial cells
Cube shaped epithelial cells
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Columnar cells
Long and narrow (column like) epithelial cells
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Squamous cells
Flat and scale-like epithelial cells
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Connective tissue
Supports the body
- provides framework for epithelial cells
- examples: bones, cartilage, blood, tendons, ligaments, adipose tissue
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Connective tissue function
-form stroma- support structure- by secreting materials to form an extra cellular matrix
39
Prokaryotes
Do not have membrane bound organelles
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Nucleoid Region
Where genetic info organized in a single circular molecule of DNA is concentrated
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Three domains of life
Archaea
Bacteria
Eukarya
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Archaea
Extremophiles--live in harsh environments
| -use alternative sources of energy like chemosynthesis
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Archaea similarities to Eukaryotes
- translations starts with Met
- similar RNA polymerases
- histones
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Archaea similarities to Bacteria
- single circular chromosome
| - divide by binary fission / budding
45
Bacteria
Similar structure to eukaryotes
-complex relations to humans
Ex) symbiosis, pathogenesis
46
Cocci
Spherical bacteri
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Bacilli
Rod-shaped bacteria
48
Spirilli
Spiral shaped bacteria
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Obligate aerobes
Bacteria that require O2 for metabolism
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Obligate anaerobes
Cannot survive in O2 environments
| -carry out anaerobic metabolism
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Facultative anaerobes
Survive in environments with or without oxygen
| -toggle metabolic processes based on environment
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Aerotolerant anaerobes
Cannot use O2 for metabolism but can survive in an O2 environment
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Envelope (bacteria)
Formed from Cell wall and cell membrane of bacteria
| -control movement of solutes into and out of cell
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Gram-positive cell walls
- turn purple Bc take in the crystal violet stain
| - have thick cell wall made of peptidoglycan and lipoteichoic acid
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Gram negative
- turns pink-red Bc takes in counterstain, saffranin
- thin cell wall composed of peptidoglycan
- outer membrane has phospholipids and lipopolysaccharides
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Chemotaxis
Moving in response to chemical stimuli
| -move using one, two or many flagella that help it move toward food or away from immune cells
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Flagellin
Basal body that anchors and rotates flagellum
| -hook connects it body and flagella
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Electron transport prokaryotes
Carried out using cell membrane
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Binary fission (prokaryotes)
The way prokaryotes multiply
- chromosome replicates while the cell grows in size
- cell wall divides cells into identical daughter cells
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Plasmids
Carries Extrachromosomal material
| -may contain antibiotic resistance genes --virulence genes
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Episomes
Plasmids that can integrate into the genome
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Genetic recombinations
Increase bacterial diversity
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Sources of genetic recombination
| Transformation
Acquisition of genetic material from the environment
| -can be integrated into bacterial genome
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Sources of genetic recombination
| Conjugation
Transfer of genetic material from one bacterium to another across Conjugation Bridge
- plasmid transferred from F+ to F- cells.
- portion of genome transferred from Hfr cell to recipient
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Sources of genetic recombination
| Transduction
Transfer of genetic material from one bacterium to another using a bacteriophage as a vector
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Sources of genetic recombination
| Transpoons
Genetic elements that can insert into or remove themselves from the genome
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Bacterial growth
Lag phase
Exponential phase
Stationary phase
Death phase
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Lag phase
Bacteria adapt to new local conditions
| -not much growth
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Exponential phase
Growth then increases exponentially
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Stationary phase
Resources are reduced, growth levels off
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Death phase
Resources become insufficient, bacteria die off
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Virus structure
Genetic material
Capsid
Lipid containing envelope (sometimes)
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Capsid
Protein coat
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Obligate intercellular parasites
| Virus
Cannot survive and replicate outside of a host cell.
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Virions
Individual virus particles
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Bacteriophages
Viruses that target bacteria
| -have tail sheath and tail fibers
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Tail sheath
Injects the genetic material into a bacterium
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Tail fibers
Allow bacteriophage to attach to the host cell
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Viral genomes
- composed of DNA or RNA
| - single stranded or double stranded
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Positive sense
- single stranded RNA
| - can be translated by host cell
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Negative sense
Single stranded RNA
| -complimentary strand must be synthesized using RNA replicate, which can then be translated
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Retroviruses
Single stranded RNA genome
- complimentary DNA strand is made using Reverse Transcriptase
- DNA incorporated into host genome
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How virus can infect
attach to receptor
- fuse with plasma membrane
- brought in by endocytosis OR
- inject their genome into the cell
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Virus reproduction
Replicate and translate genetic material using the host cell's ribosomes, amino acids and enzymes
85
Viral progeny release
- cell death
- lysis
- extrusion (leave with membrane, keeping host intact)
86
Bacteriohages: Two life cycles
Lytic cycle
| Lysogenic cycle
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Lytic cycle
Bacteriophage produces massive numbers of new virions until cell lyses
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Virulent
Bacteria in lytic cycle
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Lysogenic cycle
Virus integrates into host genome as a provirus or prophage
- reproduces along with cell
- provirus leaves genome in response to environmental factors and eventually enters lytic cycle
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Prions
Infectious proteins
- trigger misfolding of proteins
- converts alpha helix structure to Beta pleated sheets
- this decreases solubility and degradability of misfolded protein
91
Viroids
Plant pathogens that are small circles of complimentary RNA
- can turn off genes
- result in metabolic and structural derangement of the cell and potential death
