Exam 1 Cell Overview Flashcards
smallest unit of life
Cell
2 qualities that characterize life
- replicate
2. Create energy from inanimate matter
Prokaryotic cells
Little organization
ex. bacteria
Eukaryotic organisms
genetic material organized in nucleus
contains membrane bound organelles
compartmentalization
what is the importance of compartmentalization in eukaryotic cells?
Prevents mixing of pathways
allows for more sophisticated functions
allows cell to inc. size
3 eukaryotic cell structures
- cell membrane
- cytoplasm
- cytosol
cytology
the study of the structural components of the cell
Hystology
the study of the integration of cells toform tissues
3 comoponents of integration
- the cells themselves
- the ECM
- tissue fluids
what is the importance of tissue fluids
transport nutrients, hormones. gases and waste to and from cell
why do we stain cells?
to inc. contrast in light or electron microscope
2 most common stains?
- Hematoxylin
2. Eosin
When negative molecular groups bind to positively charged dyes, the stained structure is _______
Basophilic
Basic components attract positively charged dyes like _______ and are termed __________
Eosin, Acidophilic
What type of stain is used in Electron microscopy?
Electron- Absorbing heavy metal ions
Structure tat encloses the cell
Cell Membrane
Structure that anchors the cell to surrounding surfaces
Cell Membrane
5 functions of the Cell Membrane
- Encloses Cell
- area of contact for surrounding cells/environment
- involved in active and passive transport
- anchors cell to surrounding surfaces
- participates in signaling and recognition events
two types of proteins associated with the cell membrane
- integral proteins
2. peripheral proteins
where are integral proteins located
inserted in the phospholipid bi-layer of the cell membrane
where are peripheral proteins located?
attached to the inner or outer surfaces of the cell membrane
What are trans-membrane proteins?
integral proteins that span the entire thickness of the cell membrane
What 3 things can restrict protein diffusion into the cell membrane
- Cytoskeletal components
- cell junctions
- lipid rafts
what is the function of lipid rafts?
Decrease fluidity of the lipid bilayer
what are lipid rafts made of?
cholesterol and sphingolipids
what are caveolins?
proteins that are present in some lipid rafts that reorganize the cell membrane into a pear shape and are used in signaling events and cellular uptake.
what is the function of the glycocalyx?
cell recognition, signaling, mechanical protection
T/F most cells have a single nucleus?
T
what does the Nuclear envelope do?
encloses the nucleus
what are nuclear pores?
pores on the nuclear envelope that control the flow of materials between the nucleus and cytoplasm
what are the 2 unit membranes of the nuclear envelope?
- Outter membrane
2. Inner Membrane
what is the importance of the outer membrane of the nuclear envelope?
contains Ribosomes
what is the importance of the inner membrane of the nuclear envelope?
contains the nuclear lamina
what is the nuclear lamina
a Fibrous sheath composed of lamins that provide the nucleus with mechanical strength
what is chromatin?
DNA with complexed with proteins
what is the nuclear matrix
filamentous material remaining after enzymatic digestion and extraction of the nucleus
what is the function of the ucleoli
production of riosomes
T/F the nucleoli of cells usually stains with Acidic dyes?
F
what are nuclear organizing regions?
responsible for encoding rRNA and determine the umber of nucleoli in cell
T/F cytosol takes up 1/2 of the cell’s volume
T
what is cytosol made up of?
water, ions, sugar, AA, nucleotides, soluble enzymes, cytoskeletal components, mRNA, tRNA
what is the key function of the rER?
protein synthesis
what is the key function of the sER
lipid synthesis, calcium sequestration, steroid hormone synthesis, and detoxification
T/F ribosomes are basophilic?
T
what is ergastoplasm?
accumulations of basophilic, well developed rER in pancreatic cells
what is nissel substance?
accumulations of basophilic, well developed rER in neurons
What is the sarcoplasmic reticulum?
The ER in skeletal and cardiac muscle cells that sequesters calcium ions
what is the golgi complex
consists of a series of flattened cisternae with a convex of cis side that is usually orientated towards the nucleus and a concave or trans side that faces the cell periphery
where are secretory granules located?
present in specialized digestive glands and hormone producing cells
T/F All cells are capable of constitutive secretion
T
what is constitutive secretion?
continuous delivery of growth factors and components of membranes and the ECM to cell surface
T/F constitutive secretion needs no stimulus
T
how does constitutive secretion work?
small vesicles bud off from the golgi (trans region) and fuse with the cell membrane through exocytosis
the accumulation of membranes is balanced by ______
endocytosis
3 types of endocytosis
- Phagocytosis
- pinocytosis
- Receptor Mediated Endocytosis
what is phagocytosis?
ingestionof a solid particulate
which two cells perform phagocytosis in the animal?
neutrophils an dmacrophages
why is phagocytosis important for a cell?
defense mechanism against infectious organisms and removes cell debris
what is Pinocytosis?
uptake of fluid
What is receptor-mediated endocytosis
the uptake of receptor bound material
what is the importance of autolysosomes?
a way for the cell to digest aged or little used organelles
what is a residual body?
whats left when indigestible material is in a secondary lysosome
what are dense bodies?
electron dense bodies, rich in calcium in some cells
unknown function
what is apoptosis?
programmed cell death
which organelle has the capability to metabolize hydrogen peroxide?
Peroxisomes
what is the function of the cytoskeleton?
covers structures that function to maintain cell shape, motility and intercellular transport functions
what are the 3 main components of the cytoskeleton?
- microtubules
- microfiliments
- intermediate Filaments
Transports vessicles and other organelles within the cyotplasm
microtubules
what are the 2 microtubule subunits?
Alpha and Beta tubulin
2 components of microfiliments and their functions
- actin - muscle contraction
2. Myosin - directional movement
cytoskeletal structure that helps stabilize the cells shape and restrict protein mobility with transmembrane proteins
microfilaments
T/F intermediate filaments are involved in intracellular transport
F. intermediate filaments are not polorized so do not help with transport
what is the function of intermediate filaments?
anchoring and structural functions
name the 5 families of intermediate filaments
- Keratins
- vimentin
- desmin
- Gial Fibrillar Acidic protein
5 neurofilaments
a number of deposits in cytosol that do not perform specific chemical reactions and not classified as organelles
inclusions
what are the 3 types of inclusions?
- lipid droplets
- glycogen deposits
- pigments
Where do lipid droplets occur?
adipocytes, adrenal cortical cells, liver cells
where are glycogen droplets found?
liver, muscle, and neuron cells
3 types of pigments
lipofuscin, melanin, hemosiderin
non-motile finger-like projections of the cell membrane that function to inc. the surface area of cell
microvilli
projections of cell that beat in synchronous manner to produce unidirectional transport
cillia
where are cillia found?
respiratory tract
what is the name given to the central region of cillia and flagellum?
Axoneme
Arms that extend from A microtubules that attach to the adjacent B microtubules and cause a bending movemeent
Dynein
where is the basal body located?
at the base of the cillia or flagellum
somatic cells multiply by ________
mitosis
gametes increase in number by ________
meiosis
4 phases of the cell cycle
- G1
- S
- G2
- M
What are cyclins?
protein checkpoints that control the cell cycle
what are the 6 phases of mitosis
- prophase
- prometaphase
- Metaphase
- Anaphase
- Telophase
- Cytokinesis
3 types of intercellular junctions
- occluding
- Anchoring
- Communicating
what are the 3 basic components of the cell
cytosol, organelles, cell inclusions
what is hyaloplasm
the basic structureless cytoplasm,
which organelle contains the genetic information for the cell
nucleus
in eukaryotic cells, what separates the genome from the cytoplasm
nuclear envelope
T/F the chromatin of the nucleus is Acidophilic?
F. Basophilic
what are the two types of chromatin
Heterochromatin, Euchromatin
Allows for the passage of RNA from the nucleus to the cytoplasm
Nuclear Pores
what is hyaloplasm?
Basic structurless cytoplasm
what is the point of no return in apoptosis
mitochondrial outer membrane permeabilization
what are the functions of the smooth er
lipid biosynthesis, detoxification, sequestrate of calcium ions
functions of the rough er
segregation of proteins, glycosylation of glycoproteins, synthesis of phospholipids, assembly of multichain proteins
what are the 5 types of intermediate filaments
- tonofilaments,
- vimentin
- desmin
- neurofilaments
- glial filaments
what are stereocilla
absorptive nonmotile projections
considered large microvilli
____ extend from each outer pair of microtubules towards the inner central tubules
radial spokes
____ join each outer pair of microtubules with the adjacent outer pair
Nexin
Double membrand bound large structure containing chromatin
nucleus
double lipid bilayer with nuclear pore complexes
nuclear envelope
Aggrigation of cells and intercellular substances specialized to perform particular functions
Tissue
4 types of tissues in the body
- epithelium
- connective tissue
- Muscle
- nervous tissue
2 types of epithelium
surface and glandular
category of epithelium that consists of sheets of aggrivated cells of similar type
surface epithelium
category of epithelium that makes up secratory cells of the endocrine and exocrine system
glandular epithelium
type of epithelium that covers all of the external surfaces and lines the internal surfaces of the body
surface epithelium
type of epithelium that results from proliferation of surface epithelial cells to underlying connective tissue
glandular epithelium
list some characteristics of epithelial cells
protection, absorption, secretion, excretion, formation of barriers for selective permeability
the protein in the cytoplasmic filaments of epithelial cells
cytokeratin
at the basal surface of epithelial cells that makes contact with underlying connective tissue
basement membrane
what are the 2 layers of the basement membrane
lamina Lucida and lamina densa
connects lamina densa to subepithelial connective tissue
lamina fibroreticularis
3 embryotic germ layers in which epithelial cells derive
- ectoderm
- endoderm
- mesoderm
how is surface epithlium classified?
based on # of layers present and shape of cells
what is simple epithelium
single layer of cells resting on the basement membrane
2 components of connective tissue
cells and matrix
what makes up the matrix of connective tissue
fibers, ground substance, and fluid
what are the 3 classifications of connective tissue
emmbryonic, adult, and special
what are the 4 types of adult connective tissue
loose, dense, reticular, and adipose
what are the 3 types of special connective tissue
cartilage, bone, blood
what are the 6 functions of connective tissue
1 connect
- suspend/give form
- insulation and storage
- defend
- Nutrition
- repair and regeneration
what are the types of fibers found in the connective tissue matrix? (3)
collagen, elastic, and reticular
what is ground substance
amorphoous, formed by principal cells of tissue found in matrix of connective tissue
what are the 3 components of connective tissue
gags, proteoglycans, glycoproteins
types of light microscopy
- bright field
- polarized
- florescence
- phase contrast
- stereo (dissecting)
why is polarized light microscopy important?
cannot see nuclei and shows 3d structure