Flashcards in Chapter 1 - The Cell Deck (35)
What cell membrane is composed of.
Semi fluid cytosol - allows for diffusion of molecules throughout the cell.
Organizing proteins around which linear DNA is wound.
Package and order DNA into structural units called nucleosomes (grouped I to sets of 8, called histone octamers) Histones are the chief protein component of chromatin, acting as spools around which DNA winds. Play a role in gene regulation.
Histone -> histone octamer -> nucleosome -> chromatin
What is the cytoskeleton made up of (3)
1. Microfilaments (ACTIN)
2. Microtubules (TUBULIN)
3. Intermediate filaments
What are kinesin and dynein?
Motor proteins which pass along microtubules in the cell cytoskeleton
Found in centrosome.
Organizing centers for microtubules - organized in 9 triplets with a hollow centre.
During mitosis, centrioles move to opposite sides of the cell and organize the mitotic spindle.
One copy of a newly replicated chromosome (joined to the other copy by a single centomere)
Functional parts of an organ
Examples of connective tissues:
**CT often produces and secretes COLLAGEN and ELASTIN.
Start translation w methionine
Contain RNA polymerases
Associated DNA with histones
Known for using alternate sources of energy
When both humans and bacteria benefit from the relationship.
(Ie not a pathogen)
Gram positive cell wall
Thick peptidoglycan layer
Lipoteichoic acid (immune reaction)
No outer membrane
Stains crystal violet
Gram negative cell wall
Thinner peptidoglycan layer
Phospholipid and lipopolysaccharide outer membrane
(Lipopolysaccharide = immune resp, stronger than Lipoteichoic acid)
Stains SAFRANIN (red-pink) counterstain
Ability of a bacterial cell to detect chemical stimuli and move toward or away from it (via flagella)
Small DNA molecule, separate from the chromosomal DNA, that can replicate on it's own.
Linked with advantages such as antibiotic resistance.
Eg: sex factors are plasmids that contain the genes necessary for donor make bacteria to form the sex pili (appendage used for conjugation)
4 basic tenets of cell theory
1. All living things are composed of cells
2. The cell is the basic unit of life
3. Cells arise only from preexisting cells
4. Cells carry genetic info (DNA) from parent to daughter cell
Forms of genetic recombination (4) (ways for prokaryotes to obtain genetic information outside of binary fission)
A subset of plasmids that is capable of integrating into the genome of the bacterium
Transformation (genetic recombination)
Integration of foreign genetic material into the host genome. Foreign material often come from lysis of other nearby bacteria.
Gram-negative rods are often able to carry out this process.
Conjugation (genetic recombination)
Forming of a conjugation bridge between a donor male (+) and donor female (-) via "sex pili".
Transduction (genetic recombination)
Only one of these processes that requires a vector (virus that carries genes from one bacteria to another).
Bacteriophages (viruses that infect bacteria) can accidentally trap a segment of DNA during assembly. When it goes to infect another bacterium, it releases this trapped DNA into the new host cell, giving it additional genes.
Transposons (genetic recombination)
Genetic elements capable of inserting and removing themselves from the genome.
If a transposon is inserted within a coding region of a gene, that gene may be disrupted.
Bacterial growth phases (4)
1. Lag phase
2. Exponential phase (log phase)
3. Stationary phase
4. Death phase
Physical structure of a virus (5)
Genetic material (DNA or RNA, single or double stranded, linear or circular)
Protein coat (capsid)
Envelope containing lipids (sometimes)
Specific to bacteriophages:
Tail sheath (act as a syringe)
Tail fibers (recognize and connect to host cell)
Viral progeny produced by a virus once it has hijacked a cell's machinery. Virions are released to infect other cells.
Material of which the chromosomes of organisms other than prokaryotes (bacteria) are made of.
Consists of protein, DNA, and RNA.
What receptors do HIV viruses bind to on white blood cells?
CD4 and CCR5
What is a retrovirus
Single-stranded RNA virus
Carries enzyme called reverse transcriptase
What happens after a cell has been infected by a virus? (This is how the virus reproduces) IE where in the cell does it go?
TRANSLATION of genetic material
Viral DNA must go to nucleus
Gets transcribed to mRNA
mRNA goes to cytoplasm where it is translated to proteins (by the ribosomes)
+-sense RNA viruses go directly to the cytoplasm to become proteins
--sense RNA viruses need to make a complementary RNA strand via RNA replicate, and then can be translated to make proteins.
DNA from retroviruses goes to the nucleus where it can be integrated into the host genome.
What components are used to translate RNA into proteins?