Lecture 2 - cell organelles Flashcards
Stromatolites
photosynthetic properties and deposit a calcium carbon sediment and formed fossil. Release oxygen.. Contain cyanobacteria
Evidence that archaea were host cell
Archaea contain DNA with introns and promoters, histones, RNA poly and transcription factors similar to eukaryotes. Also they glycosylate proteins
Nucleus
site of most cellular genetic DNA
Centriole
helps organize microtubules during cell division. organization of microtubules into triplets
Ribosomes
manufacture proteins
ER
site of protein and lipid production
Glycocalyx
saccharides attached to glycolipids and glycoproteins
Nuclear envelope
selectively permeable barrier. Consists of an inner and outer membrane
Inner nuclear membrane
associated with the nuclear lamina protein meshwork that binds to chromatin in non-dividing cells
Outer nuclear membrane
may be covered with free ribosomes and can be continuous with the RER .
Nuclear pores and their complex
control fluids into and out of the nucleus. Complex is 8 fold symmetry. Uses transporting proteins to chaperone
Nucleolus
makes rRNA
3 Pars regions in nucleolus
Pars amorpha, pars fibrosa, and pars granulosa
Pars amorpha
consist of DNA sequences encoding for rRNA. Also known as the nuclear organizer
Pars fibrosa
consist of primary rRNA transcripts
Pars granulosa
represent maturing ribosomal subunits (granules of pars fibrosa)
Nucleolonema
pars fibrosa and the pars graulosa only
Heterochromatin
Heavy staining. When DNA associated with various proteins is clumped
Euchromatin
Light staining. DNA associated with various proteins is unwound.
Binary fission
mode of division for prokaryotes, looped DNA makes an identical copy.
G1 phase of mitosis
growth phase. When cells are doing their normal activity
G2 phase of mitosis
proteins being made for mitosis
S phase of mitosis
synthesis phase
Phases of Mitosis
Interphase (G1), prophase, metaphase, anaphase, telophase, cytokinesis.
Free ribosomes produce what type of proteins
cytosolic and cytoskeletal proteins and proteins for import into the nucleus, mitochondria, and peroxisomes
RER produce what type of proteins
proteins incorporated into membranes, stored in lysosomes, or secreted from the cell. Often need further processing.
5 Functions of ER
cleavage of signal peptide; protein folding; attachement of oligosaccharides; Smooth ER synthesize phospholipids, fats, and steroids; enzymes responsible for detoxification of drugs and other harmful substances
4 steps of protein folding in RER
signal peptide cleaved, elongating protein pushes into lumen with help from chaperones, undergoes proper folding and posttranslation modifications, if cant be folded, translocated to cytosol and conjugated to ubiquitin and degraded by proteosomes.
Golgi apparatus
modifies, sorts, and packages proteins from the ER. Cis and Trans side. Stains with silver
Cis and trans of Golgi
Cis - closest to ER
Trans - transporting the forming vesicle.
Coat Protein II (COP II) vesicle direction
promotes forward movement of vesicles. From ER to cis Golgi
COP I vesicle direction
Promotes retrograde movement of vesicles with help from KDEL receptor. From Trans/cis golgi to ER
Mannose-6-phosphate marker
Marker for segregation for lysosomes.
optimal pH activity for a lysosome
pH 5
secondary lysosome
fusion of a primary lysosome and another vesicle
Peroxisomes
generate hydrogen peroxide. Oxidize harmful substances and long-chain fatty acids
Melanosomes
membrane enclosed granule containing melanin
Lipofuscin
membrane enclosed lipid-containing residues of lysosomal digestion (residual body/tertiary lysosome)
Actin’s intracellular movement
form stress fibers that play a role in contractility and motility by changing contracting to change shape
Actin’s structural role
forming the terminal web attached to the zonula adherens underlying the apical cytoplasm.
Actin’s membrane structures
microvilli and stereocilia
Filopodia
finger-like projections that are used in sensing, locomotion, and cell-cell interaction
Microtubules
heterodimer. can be individual, doublets as seen in cilia, or triplets as seen in centrioles
Axoneme
organization of microtubules into doublets to form the core of cilia (flagella) and the sperm tail.
Actin
Microfilaments
Cilia
Microtubules
Motile cilia
contain a central doublet of microtubules
Primary cilia (non-motile)
lack a central doublet of microtubules
Desmosomes
hold cells together with the next cell
Keratin
intermediate filament. attach to desmosomes.
Zonula Occludens
Tight junctions. occur at the apical sufrace. Prevent material passing between and create cell polarity (orientation).
Zonula adherens
intermediate junctions. Occure below the Zonula occludens and make up the web and hold cells together. Forms the terminal web and anchoring point for microvilli.
Two proteins in tight junctions
claudin and occludin
Hemi desmosome
anchors the basal cytoplasm to the basal lamina of the basement membrane. Cadherins are replaced with integrins.
Two proteins in desmosomes
Desmoglein and desmocollin that insert into plakoglobin and desmoplakin
Proteins in gap junctions
six connexin proteins form a connexon.